Society of American Silversmiths - PUK 5 and PUK Pulse Arc Welders Reviewed, PUK04 Review

As any silversmith knows, silver solder is the ideal material to use when joining sterling pieces by the traditional method of brazing. Sometimes I will receive an object which has been lead-soldered in the area in need of repair (or re-repair). Sometimes the joined area is not visually accessible, and I don't know if lead has been used.

In either case, I cannot use silver solder because the high temperature required will melt any lead in the joint and allow it to form its own alloy with the silver. Not pretty! And, using a low temperature tin/silver solder won't give me a sound joint or good silver color. For this reason, I had been exploring newer technologies for joining metals. I tested laser welders from a few manufacturers, but found that their compartments are too small for working on holloware. In addition, they are expensive to buy and notoriously expensive to repair, and the down-time for repairs can be substantial. I also tested the Mini Pulse III (an arc welder) from Aelectronic Bonding, which had too few welding power options and didn't allow me to get into tight spaces.

I tested a friend's Lampert PUK2 pulse arc welder for a few months, and refined my technique to the point where I felt confident to purchase Lampert's PUK3s Professional, which was developed to weld silver more successfully. I was so impressed that I soon purchased the PUK3s Professional Plus which had a broader power range, additional impulse settings, and five programmable settings.

The 10 electrodes come pre-sharpened on both ends. I wait until I have used all 10 electrodes (20 tips) before sharpening them at the same time with the supplied mandrelled diamond disk. This saves time. I mount the disk in my Foredom handpiece and secure it to the bench over the dust collecting vent. The recommended tip angle is 15%. Electrode replacement in the PUK handpiece can be accomplished within five seconds.

Whether it be pulse arc or laser, welding isn't meant to substitute for brazing large objects. Welding long seams (e.g., on coffeepots or candlesticks) is more time-consuming than simply using the welder to tack a seam in preparation for brazing.

If attaching parts to large bearing surfaces (e.g., a large finial to a coffeepot cover), it's best to tack the part in place, then use the capillary action of torch-brazing to fill the void. Always consider the time it will take to weld or braze and the subsequent clean-up.

The handpiece can be removed in three seconds for welding freehand.

Lampert pulse arc welder highlights

• Uses the same alloy as the piece being created or repaired (no color issues as with solder);
• Tacking eliminates the shifting of joints and the time involved in wiring-up an object;
• Repair objects without harm to stones or patinas;
• Attach findings without losing metal hardness;
• Work on material as this as .0005";
• No firescale or firestain due of argon protective atmosphere;
• Localized heat won't melt nearby joints or damage stones;
• Fill-in porosity with the same alloy;
• Simple and intuitive to operate;
• Certified product safety: GS & CE marks;
• DIN CERTCO certified eye protection in the microscope lens;
• Maintenance-free;
• Small footprint - fits into every workshop;
• Very low cost of consumable materials (electrodes);
• Extremely low argon consumption compared to other systems (I use only 1.5 lpm);
• Touch-screen operation;
• Easy-on, easy-off handpiece nozzle when changing electrodes;
• Built in Germany with attention to the minutest detail - you can see and feel the quality;
• 3-year warranty!

SM5.1 Microscope
PUK® Flow Regulator ($250 value)
Precision Handpiece
(2) Alligator Clips

(6) 0.6mm Inostar Electrodes
Diamond Grinding Wheel
Fiberglass Cleaning Brush

WARNING! Shaded safety glasses and goggles made for oxy-acetylene brazing and welding are NOT intended for arc welding. The flash that's produced when arc welding is much more intense and requires the auto-darkening function found on PUK pulse arc welding microscopes and magnifiers.

This updated articulating arm ($575) allows me to work on larger objects underneath the microscope. It swivels 360 degrees and secures with the twist of only one knob.

Allows for relaxed and fatigue-free working with the welding microscope. It also helps maintain concentration on the workpiece and eliminates fogging and the deposit of eyelash oils on the microscope lens.

Argon gas, which protects the weld from developing oxides, is the other expense for running the PUK. Without gas, the PUK won't run (and you would never produce a successful weld without it, regardless of your chosen welding apparatus). To reduce the cost of argon, I would advise leasing a 300-cubic-foot cylinder (5' tall x 10" diameter). I'm paying $75.20 (Industrial Welders Supply in Rhode Island) per refill (includes hazmat & state tax) plus $50 for the yearly lease. Argon purity of at least 99.997% is recommended by Lampert.

Carbon Dioxide: <1ppm
Nitrogen: <20ppm
Oxygen: <5ppm
THC: <1ppm
Water: <10.5ppm
Dew Point: -76F

I have been running the PUK on 1.5 liters of argon per minute regardless of the alloy I'm working with.

Definitely purchase a Speedwire Welding Wire Dispenser (not a Lampert product).

Welding wire spooled in containers like the ones above make it difficult and time consuming to steady thin wire exactly where you want it (it tends to flop around). The Speedwire Welding Wire Dispenser makes thin wire much easier to weld since it puts it exactly where you want it – without movement. Speedwire allows wire as this as .005" (.127mm) to be dispensed, though, you'll probably be using the more widely available .010" (.25mm) wire. I bought the refillable Speedwire ($23) and coil the sterling wire myself on steel rod in my lathe, then relax the coil by removing the wrapped rod from the lathe and gently annealing it while still attached. Speedwire can also be supplied with pre-installed wire of numerous precious metal alloys. See the Speedwire in use here, and see how the receptical can be filled. For more information and purchasing from the inventor, go here. Speedwire can also be purchased from: Hoover & Strong, Rio Grande, Stuller, among others.

Using this relatively new technology has broadened my scope of options when joining metals. I can mend a pinhole with a dollop of sterling, dress it down, and give it a quick polish without disturbing the patina. The end result: absolutely no indication the piece was repaired - the color is perfect! I can repair a bezel surrounding a piece of glass without removing it. Normally I would be forced to unmount the glass, possibly damaging it in the process. I even used the PUK to weld a steel wire to the end of a hardened steel pin that was buried in a candelabra stem. I heated the stem, melting the lead solder, and pulled the pin out. How slick is that?

When I say I use the PUK every day I'm working, I'm not exaggerating. It was the most prudent (and expensive) purchase I've ever made for my shop, but it's already paid for itself. Once you own this little gem, it will open a whole new world of possibilities. Oh, another plus: Lampert Tools USA offers up to five hours of free training when you purchase a PUK welder. Simply contact owner and goldsmith Robert Sepiashvili in Chicago to make an appointment.

Lampert Tools USA
Robert Sepiashvili
67 East Madison #512
Chicago, IL 60603
866/4PU-K111 (866/478-5111)

Have you ever been so frustrated that you throw-up your hands when welding heavy-gauge silver? Well, let me try to help. As with brazing silver, you know you need to bring up the temperature of the metal in order to solder successfully. The same is true for welding, though, to a lesser extent. Solder is attracted to heat and so is welding wire. There are times when I'm welding a heavy casting or fabricated piece and I will first heat it. Perhaps it's under a heat lamp, hairdryer, or hot air gun. The point is, welding to a cold surface which isn't immediately warmed by the welding process itself will be considerably harder. I'm sure you've noticed how much easier welding wire melts to the base material of a smaller piece. It's because it warms more quickly. Even using the smoothing method may not help get the job done. You may even need insulated gloves when working on larger pieces, especially when using higher power and milliseconds. So, make sure to prepare those larger pieces of metal prior to making your initial weld and let me know how it worked for you.

There have been times when I needed to reattach parts to white metal objects or add material to weak joints. In these cases I have been using tin/silver solder and pulsed the material into and onto these areas. It gives a substantially stronger join than traditional tin/lead alloys and also offers a much better silver color. Here I added the tin/silver between the body of the piece and the handle, which originally had a solder seam that was much too thin. The seam is in an unfinished state...

On the foot of the same piece, I reinforced the back so it would better support the weight of the object's body. Many white metal objects were never made for practical use since the alloy is so soft. When blended, I will apply a black patina to blend with the rest of the foot...

Well, this was a not-so-fun project. What you’re looking at is a sterling casserole dish with a dented handle that I tried removing by drilling a hole, tapping it, then pulling. The dent was pretty severe prior to removal, and, unfortunately, I hadn’t taken a picture before the repair. Anyway, the next method of attack was to drill two holes on the opposite side of the dent and try pushing it out with a steel rod. As you can see that worked up to a point but left the surface bumpy. I was going to use sterling wire to fill-in the lower areas and the hole that were left, but decided to use a much more straightforward technique. I cut out the damaged section with a separating disc and made a partial ring to replace it. (Lesson learned for the next project of this type.). I put a bevel on the top corner of the sheet and welded it in place with sterling/platinum wire. I then compacted the welds, leveled the surface with 2000-grit paper and polished.

This little Chinese Export cutie came to me for three new forged toe implants welded in place with Herman's Sterling/5% welding wire.

I'm sure many visiting this blog don't get anywhere near white metal. Should you run into a piece that needs repair, tin/3% silver solder does a fantastic job! On this 12" tall silverplated piece, I used the alloy and the silver setting to mend a deep crack in one of the under-branches. The tin/silver melded beautifully and gave a nice bright silver finish, perfect for a plated piece!

This trach required the inner cannula swivel clasp to be secured. I enlarged the head on top of the tubing with sterling so the clasp wouldn't slip off. The flapper plate's flap was leveled as it wasn't closing completely, allowing air to escape. I added sterling to the tip of the outer cannula which had worn thin.

Above: This trach required the inner cannula swivel clasp to be secured. I enlarged the head on top of the tubing with sterling so the clasp wouldn't slip off. The flapper plate's flap was leveled as it wasn't closing completely, allowing air to escape. I added sterling to the tip of the outer cannula which had worn thin.

My arm rests are topped with rubber from floor tiles – they're extremely comfortable.

When you're welding and your electrode loses its sharpness, extend its pulsing life by turning the knob clockwise one click at a time, increasing the power. Give it a try!

Today was the first time attempting to weld nickel. Not fun. No, not fun in the least. I eventually found a decent setting:

Bronze
Power: 40%
Milliseconds: 2
Mode: Corner

Now here's a snazzy idea! Ya know that threaded sleeve that knuckles down the internal chuck on your handpiece? Your fingers sometimes slip on it, right? Wrap it with some shrink tubing which will give you a better grip!

Have you ever had a drill bit drift off course? Well, that's what happened with this flask cap. I tried drilling-out the hinge pin and it thinned the inside diameters of a couple of hinge knuckles. Instead of trying to round-out the hole by filling it from the inside, I pushed in the thinned area and added metal from the outside, which you see here. The hinge wire provided a form to burnish the thinned area around as well as backing-up the knuckle so the area wouldn't collapse from the pulse.

I tested the wheel against Lampert's standard wheel and the result is impressive, resulting in a sharper point and uniformity of cut = better welding outcomes. Top electrode sharped with Xtra Fine disc...

This sterling rooster decanter required some filling-in of the damaged wire rim. Because of the object’s size, Lampert’s articulating arm made the operation successful.

Another stab totally constructing a piece using the PUK welder. This 2.5" pin took much longer than brazing, but I was able to weld the top prong in place after the moonstone (from high school days) was inserted. The piano wire was again welded inside the tubing, and the overall piece is stronger than if I brazed it because some of the elements were hardened prior to attaching.

1. Braze most attachments;
2. Weld the pin in the tubing;
3. Weld the top prong in place after setting the stone.
The above steps would save time and leave cleaner seams.

It's been years since I made a piece of jewelry. This 3" sterling pin with rutilated quartz was entirely constructed using sterling/5% platinum wire and the PUK pulse arc welder.

Tacking long joints rather than using binding wire guarantees perfectly aligned seams. With sterling, my welding wire will work much better than simply pulsing on the seams as the added platinum gives a much stronger tack. Of course you will still want to heat the piece evenly prior to concentrating the heat on the seam.

As you may have discovered, welding objects with pitch inside can be a challenge. In this particular case I had to cut the cup from the stem, remove the pitch, then char the residue. Welding with char in vacinity will be more successful than having the possibility of pitch oozing into the seam and contaminating it.

There are occasions when I’ll use .020” (0.51mm) sterling wire to weld very thin material, like the ferrule pictured below which is made of .005” (0.18mm) sheet. Practice on some thin-gauge material by drilling holes and using some heavy wire, like what I used. Use the sterling prong setting with 30% power and 3 milliseconds. Put the wire in the hole or over it and place the electrode on the wire at a 45% angle, pointing towards the edge of the hole. On the second pulse, put pressure on the wire so the heat from the pulse will “grab” it and continue filling the hole. It will take some practice, but when you become proficient you’ll fill those holes more quickly than using the normal .010” (0.25mm) wire. Good luck!

Are you keeping your welding sight line clean? Your microscope lenses and underplate gradually get dirty and perhaps you think your vision is failing. Keep a Selvyt cloth and cotton swabs nearby and clean those lenses – often. Your eyes will thank you ;~)

A few days ago I was soldering a white metal foot back on the leg of a silverplated gravy boat. The temperature of the foot got hotter than I expected and the holding tweezer sank into it. Very unfortunate to say the least. Thankfully, I was able to fill the sunk areas with a 96.5% tin / 3.5% fine silver alloy that I normally use as a solder that melts at 450F (232C). I then burnished the form back to its original shape. I used the sterling and prong settings with 35% power and 3.5ms.

This mixed metal necklace came to me with the headed post missing. I hard soldered a sterling wire to the disk and welded it to the back of the dome. Soldering would have changed the color of the piece.

Use a Selvyt cloth to wipe the eyepieces and shielding glass under the magnifier to maintain a clear view of what you’re welding.

These images came to me from a PUK 5 user. She was having trouble with voids in her welds as seen below. The sterling metal thickness is .5mm.

Below is a sample piece I welded using these settings: Power: 20%, MS: 1.5. I used a sharp electrode and placed in on the piece being welded and pushed welding wire's tip against it. The heat drew the wire and deposited it without any edge voids. Placing the electrode directly above the wire and pulsing down may result in the voids. If that's the case, place the electrode tip on the edge of the puddle. Again, this will draw the material to those voids. You can also angle the electrode 45 degrees directly above the puddle and pulse outward toward the void. This will shoot the metal into void.

Do your arms sometimes get fatigued when welding large objects? If so, try resting your arms and the piece you're welding on a pillow! For safety purposes I'm looking for some flame retardant material as a cover.

Feeling pain your arm from welding? It may be from grasping the object for an extended period of time. This leads to diminished blood flow in your arm because of very little movement, which can lead to tendonitis. I have a timer directly above my welder and it's set for 15 minutes. When the alarm sounds, I set the piece down and shake my right arm (the arm I use when holding the object or the handpiece) to get the blood flowing at a normal rate. I also do some shoulder rolls (going backwards) remove any stress in my neck. Keep in mind that I weld a lot of holloware, which can take substantially more time than repointing a prong.

On a related subject, I do a lot of road cycling. When my hands are on the top bar, my fingers are loosely draped over it, otherwise, I would develop numbness in my hands and increased vibration up my arms, which I keep slightly bent.

It happens to all of us: we suddenly end up with a gob of alloy on our electrode. Instead of removing it and replacing with a new one, file the solder off while resharpening the tip. Removing this glob will also make it easier to resharpen your electrode with the diamond disc.

There may be times when you'll receive cracking even when welding annealed sterling. If you have trouble trying to find a resolution, simply use a pulse of some sterling/5% platinum welding wire. It will meld with the standard sterling and produce a bright, crack-free weld.

Are you receiving numerous air pockets which lead to sputtering? After making a deposit of whatever alloy you're using, place your electrode on the edge of the "jelly bean" and pulse. You'll see the bean will level out so that the next deposit you place next to the "puddle" won't trap air. This pulsing levels the bean because the alloy is following the heat of the electrode tip. Think of it as brazing; the solder will travel to the heat. You can test the solidity of your weld by pulsing over the entire surface. If there are air pockets, they will make themselves evident.

There's a specific setting that lends itself to welding with a blunt electrode and sterling/5% platinum or silver/palladium wire. I'm sure it would work fine with JSS wire as well, but I have none left to experiment with. Try this:

A strong, attractive catch starts with a 45° undercut and pulsing wire into it (I used my sterling 50% platinum for strength). So many times I have seen attachments that have been welded around the edge displaying an unfinished appearance. I used blue, pink, peach, and light green 3M radial bristle discs for finishing (https://contenti.com/3m-radial-bristle-discs). I only welded this one side. The catch itself is 4.5mm tall...

These are my most commonly used contacts. Notice that all the plugs and contacts are coded for quick identification.

This electroformed figurine required one of the more difficult welding techniques as the silver on it is only .003" (0.076mm) and it's covering wax. The first image shows the figurine at 13cm tall.

The second image shows where I inserted sterling wire at the top of the figurine's left thigh where there's exposed wax. I continued doing so until there is no more exposed wax. You can see where I started to weld the wires towards the front of the thigh. I then pulsed the wire onto the thinner metal so it won't blow holes into the wax. So, the molten metal from the wire was literally being thrown onto the electroformed silver. That 8mm area was eventually leveled off with additional welding wire. I'm using the prong setting with 35% power and 2.5ms.

This sterling flask came to me because the threaded top wasn't fully engaging the thread. The silver deposits you see have not yet been smoothed as I wanted you to see how I was building up the thread. To see where the low points were that would require more silver, I used a black marker and lightly screwed the top down. I used the sterling/prong/35% power/25ms settings. Very satisfying!

Weld a wire from one end of the hole to the other then pulse additional material onto both sides of the wire while backing away until the hole is filled. Here I used .010" (.25mm) sterling/5% platinum wire.

My customer brought me this 1.5” silver-plated money clip which had come apart. I had to weld one hinge holder back in place and reinstall the steel torsion spring. Pretty easy, right? WRONG! When attempting to reinstall, the spring popped out, hit the far left wall and was never to be seen again s**t!

I had a stash of other tiny springs, but nothing as long as was originally used, but at least the size was perfect. The problem was how to compress all three springs to insert between both sides of the money clip plates. Oy vey! After numerous attempts, even making special pliers, it came to me: weld one of the two “arms” of each spring in place on one plate, then, with the other plate roll over the standing arms to push them down into place, then insert the hinge pin! Brilliant (if I do say so myself ;~)! So, what you’re seeing is three arms welded to the inside bottom plate. I used the silver setting, 50% power, 20ms.

Have you ever had a job like the one below, where there was a split that developed under some engraving? Well, that's exactly what happened with this piece. The two images beneath the top one shows what happened. The paddle material was extremely thin, causing the split from constant flexing. If I had brazed the split, the solder would flowed into the engraving itself, damaging the piece. And this is where the PUK excels. I used a v-shaped graver and went over the split just slightly so to not encroach into the engraving itself. I then pulsed wire into it. This technique saved any engraving on the top surface from being filled. I used the sterling setting with the prong mode, 35% power, and 2.5ms. The filler material was stering/5% platinum as the paddle was hardened.

Below is a sheet of .022" sterling welded to a .038" stainless wire (don't know the alloy). I used the silver setting, thick mode, 50% power and 3ms. No filler was used. The welds are bright and crack-free. This would be the perfect application for attaching a stainless pig tail pinback to a brooch.

Creating a piece of jewelry using hardened material will last longer. Why not try welding your entire piece rather than brazing?

As you know I do a LOT of pulse arc welding. If you've ever had trouble welding sterling, this wire will increase your productivity and give you outstanding results! These are the reasons I use Sterling/5% Platinum Welding Wire on silver alloys and occasionally other metals:

• Crack-free, glossy welds
• Best color wire for all silver alloys
• Stronger joints
• Melds well with other metals including silver solder
• Even works with dull electrodes

LEFT IMAGE: A ring of sterling .750” in diameter x .070” thick and ½ hard. The ring had been deformed prior to rounding. I filed an abnormally wide v-groove where both sides came together. The reason for this was to see just how strong Sterling/5% Platinum (alloy) was when used as a major element, not just as a minor filler. Using a Lampert PUK5 welder, I filled the groove with the alloy to a height of .060”, .010” less than the ring thickness. I then rounded the ring over a tapered mandrel with a rawhide mallet resulting in the image below. My findings while filling the groove prior to rounding the ring:

1. Glossy, crack-free welds even when using a blunt electrode. I discovered the same results when using both the silver and platinum settings on the PUK5.

RIGHT IMAGE: After rounding the ring, I cut the seam and polished one edge to see if there were any welding gaps. There were none under 15x magnification.

This is an alligator clip which I put three layers of shrink tubing on one side, and ground down and polished the copper teeth on the other. This way the rubber, not the teeth, will securely hold the piece you're working on. I placed shrink tubing on the handle as well because the clip can get very hot when welding at high power or milliseconds.

This is an additional way I use Lampert's flexible contact strip. I cut the covering from the majority of the woven cable then put shrink tubing on the end so it won't fray. I can then wrap the strip around what I'm welding and hold it in place with a drawstring cinch like you would find on a rain jacket. This is also more gentle than an alligator clip!

2/8/2018: Tying off cable ends

Below is the back of a beautiful Mexican sterling neckpiece. It was dissembled, polished, cleaned, then restrung with 49-strand coated stainless cable. The cable ends were brought into the tubing and sterling beads were crimped on the cable.

I then welded the beads to the tubing using the prong setting with 25% power and 2.5ms. I clipped the cable ends and used an ultrafine silicone wheel to smooth the crimped beads so there were no sharp edges, gave it a final polish, and degreased the area.

I just purchased one of these knife edge burs to grind out cracks in order to make them easier to fill. I'm sure there will still be times when I'll use my gravers, but this tool makes more sense, especially when getting into tight areas.

Yesterday my furnace flame went out. I welded this copper alligator clip to a steel coat hanger using Argentium welding wire on the universal and wire-feed settings. I then lit a match and fed it under the furnace to ignite the pilot light. Cool!

If you own a PUK articulating arm and would like more versatility when welding, try welding on top of a lazy Susan (pictured in green). You'll be able to rotate the piece with your wrists rather than constantly raising and lowering your hands. On top of the of the lazy Suisan I have a round block of wood, plastic container covers, and a sandbag, all in place to give me options in welding height. The microscope stays in a relatively constant position, allowing me to sit up straight and not have to bend my neck. With this setup, I can literally weld all day without pain, although, I occasionally get up and stretch.

Below I'm welding small corner dents on this 2' sterling paneled corner piece (one of a pair) for a gaming box. I even filled sharp nicks on the panel faces. Hammering the dents out would have deformed the flat surfaces, rendering the piece useless.

This sterling coffeepot cover had chased beads that were over polished leaving voids. The image on the right shows those voids filled. I used the prong setting feature with 30% power, 1.5 ms, and smoothing mode for speed. After filling the holes from the top, I flattened the resulting weld nodules on the inside using the same settings.

10/5/2017: When a pulse arc welder is your absolute BEST choice for a restoration

The cherub of this sterling bell had broken off at its left toes and right ankle. Since it was originally brazed to the top of the bell, the welder was my only consideration. I was able to make a seamless mend using Argentium welding wire topped with sterling for a perfect color match. Since the cherub was cast, Argentium produced a much stronger join.

The sugar shaker on the right lost its top and the collector requested that I create a new sterling piece using the salt top as an example. I made tubing and raised in the top then welded a cap in place with sterling for a perfect color match. I brazed half-round wire to the tubing and drilled the holes before polishing.

Alloy: Silver
Mode: Prong Tipping (This was a sterling barrel with plastic insert which required a delicate setting).
Power: 30%
MS: 2

What I especially appreciate about the Argentium welding wire is that successful welds without center-line cracking can be accomplished with blunt electrodes, saving time. And as I mentioned previously, this alloy offers impressive results when welding hardened sterling and other silver alloys. And if you're lacking brass welding wire, the Argentium works equally well when welding brass objects. Did you find yourself short of stainless welding wire? Another reason to have Argentium on hand!

One method of welding ring shanks so there are no gaps on the back side is to attach a very thin strip of metal to the back of the seam. Run your electrode into the v-groove over the entire length of the seam, melding the strip to the shank. Then fill the groove with your welding wire. You'll notice there will be no gaps after grinding away the strip after welding.

This sterling ring had been cut open and expanded for a larger finger. I first closed the separation (left) and used a triangular file to form a "V." I then welded the bottom of the V in order to close the split. I filled the V with sterling using .010" in the bottom half and .017" wire to the top, adding extra for burnishing. The reason I used the larger diameter wire was to fill the void more quickly. I filed the seam until there was a paper thickness of metal from the shank. Next came light burnishing of the top and underside to compress the silver. I finished with 2000-grit silicon carbide paper and bronze wool as a final finish to blend with the rest of the ring.

The sterling match safe below required the striker split to be filled with sterling. The thinnest material was .005" while the primary body thickness was .015". I used .017" wire and placed it on a slight angle over the void then positioned the electrode directly over it, pulsing the wire into the approximate .040" wide opening. The wire spread (sprayed) over the entire void. The reason the thinnest material didn't vaporize was because the wire temperature had lowered by the time it attached to those areas.

Before attempting this technique, experiment on a piece of scrap silver to make certain you calibrate the proper settings.

Sterling belt buckle splits aren't unusual because of the pressure exerted upon them when securing the belt. This was the case below; in fact there were breaks on both sides. I opened the splits with a v-shaped graver and filled 3/4 depth with Argentium welding wire which made the repaired area much stronger than using straight sterling. I then topped it off with sterling for a perfect color match. And since the hinge pin was a bit loose I decided to tack it in place so it wouldn't come out.

2. You're using the larger chuck jaws which won't secure the smaller diameter electrodes;

3. When installing electrodes, the oils in your fingers have been deposited in the chuck jaws making them slippery. Remove the chuck jaws and degrease them.

This wrought sterling butter spreader snapped in two probably because it was too brittle. This is another case where Argentium silver welding wire had to be used because of the object's hardened state. I filed all the edges of the break (front and back) to a point and welded the blade to the handle with the Argentium. I continued filling the gap until it was about 2/3 filled. Because the Argentium color doesn't quite match that of standard sterling, I pulsed sterling in the remaining 1/3 of the void then finished it with 2,000-grit paper and 0000 steel wool to match the rest of the piece.

6/8/2016: Do you miss the versatility of the three outlets you had on the PUK04?

5/15/2016: Testing the new PUK5: Welding Argentium Sterling 935 with Argentium silver welding wire

Two pieces of sheet were angled and tacked-welded at the top and bottom corners prior to flooding the v-groove with the welding wire. The sheet was then folded. (The line along the left edge of the weld is not a crack.)

As with the previous test welding Argentium using the PUK04, this test was also successful using the PUK5 and it's programmed welding wire setting of 4ms and 45% power.

Last week I started testing the new PUK5 and comparing it to the PUK04. The PUK5 sits to the right. Preliminary testing compared to the PUK04...

* Smaller footprint;
* Simpler display;
* Single button control;
* Faster welding speeds;
* New "smoothing" feature flattens your welds for quicker finishing;
* More comfortable rubber eyepieces on the microscope (crucial for long periods of welding);
* More affordable: $4,795 (regulator included!). The PUK04 base price was $5,295 not including regulator.

4/9/2016: Brazing to a convex surface.

This Tiffany sterling ladle handle was missing its bird finial. My customer found one that closely matched the original. Normally I would have had to pin the bird in place, but all I had to do with the PUK was tack it in a couple of spots then braze it and apply a patina to give it an aged appearance. Prior to brazing, I drilled a small hole in the ball to let out any moisture that may have remained inside. After the brazing I welded the hole closed.

This fused plate finial support was in two pieces and crushed. Being sterling fused to a copper core meant that I had to add sterling to the edge when reassembling. Normally, the sterling on the top edge would have been burnished over the copper concealing it. The welded sterling accomplished the same thing. Here the welding is in its raw state prior to burnishing and finishing.

This is the top portion of an enormous cast sterling candlestick. It had been dropped on its edge and dented. If I hadn't had my welder, I would have had to cut sterling sheet and brazed it in place. Being able to fill-in the dent went much faster. Since this was a substantial dent, I used .020" (.51mm) dead-soft sterling wire with settings of 9ms, the "thick" setting mode, and 65% power. Welding time was approximately five minutes. All that's left to do is blend the weld with the rest of the rim and polish.

The customer of this sterling inkwell wanted major dents removed but didn't want to go to the expense of having me remove the plaster and push them out. Not a problem, I just filled them in with sterling!

Are you looking to use your electrodes longer between changes? Try grinding a longer taper and don't put a definite point on the end. If you leave a flat that's .001" - .002" in diameter it won't be blown off and you'll be able to use that point for a longer period.

This Chinese vermeil and enamel container cover came to me very sad looking. The best way to repair it was to push up the right side of the finial then cut the soldered connections around the middle. I then reformed each "cup" over a dapping punch and welded the connections with 14K yellow gold. Using any method other than pulse arc welding would have been problematic because I would have had to remove the finial stone and the plating would be destroyed from the heat.

This was one of those "make it salable" jobs for an antique dealer, so I made it look presentable without doing a full restoration which would have been very costly.

This type of restoration was always tricky prior to pulse arc welding since I would have had to use a low-flo lead solder.. The key fob – which was only about two inches in diameter – had its shield reattached twice with laser welders. The customer noticed that I offered a different technology and asked if I would try it. Upon receiving the fob, I removed the previous welded material on the contact points so I could start fresh. I then angled the bottoms of the feet so I could weld into and out of the bottoms, making a complete connection to the ring. I gave the customer a on-year warranty against the shield falling off under normal handling conditions.

The plain portion of the handle on this 13" punch bowl (not including the handles) had to be removed and dents filled with sterling. (It was a casting that was too heavy to pull out the dents.) Reattaching it required no binding wire or other holding device, only four pulses with the welder to secure it in place. I removed the handpiece from its holder and did the welding freehand while looking away when I heard the "beep" – the indicator when the capacitors are about to discharge. A liquid flux was then applied to the seams and the bowl sprayed with liquid flux via a Badger airbrush to prevent firestain.

Sterling test: There are instances when putting a weld under stress is better handled by using a different alloy than what's being welded. In this experiment, I beveled the edges of two flat sheets of standard sterling. The starting dimensions of the sheets butted together were .450" x 1.5" long x .038" thick. I deposited Argentium laser and arc welding solder (76% fine silver) into the "V." The sheet was bent on the weld to the form what you see below, then polished along the welded seam. I found that the solder performed at least as well as Lampert's palladium/silver welding wire – with a better color and at a substantially reduced cost. Remember, you can always leave a few thousandths on an inch in the weld area in order to layer sterling on top for a perfect color match. If you are interested in purchasing the solder, it's currently only available from Cookson Gold in the UK. Their wire is 1.44mm square and will have to be drawn into thinner round wire. The material will soon be available as actual welding wire from Rio Grande.

Argentium Sterling test: I used the same technique using the Argentium laser and arc welding solder on 935 Argentium sterling sheet (below), but this piece was hammered flat after bending. Impressive.

There are times when no other method of restoration is practical other than pulse arc welding. The piece below is a detail of the Hartford Bishop's crozier. It came to me containing lead solder from a previous repair and poorly applied lacquer. Two thistle elements had become detached. I was asked to remove all traces of lead that was used to solder the elements in place. The heat of the torch also discolored the lacquer - what a mess. I was able to reattach the thistles without further damaging the lacquer and coated those areas with Renaissance wax. The crozier will have its lacquer stripped and hand polished at a later date.

There are times when welding that no matter what you do, the weld fails. Perhaps there are minute amounts of dirt on the inside of an object that you can't see or remove. Maybe the inside of a piece was never cleaned after brazing and corrosion developed. There may also be areas that were repaired with unknown solders. Whatever the case, here's a technique I developed when I had this very problem. I was working on a double-walled sterling oil lamp which developed a small hole allowing vegetable oil to leak into the basin. I removed over two cups of oil, but was unable to remove the basin cover to thoroughly remove the residue. A solder seam had opened and needed to be welded closed. I removed the solder in the seam and hoped the oil residue wouldn't contaminate the joint while welding. It did. Whatever setting I used would allow the oil to migrate to the surface. I decided to try something radical. I ramped up the milliseconds to 20, chose the thick setting, and cranked the power to 60%. What happened, I believe, was the seam and surrounding area was cauterized from the extreme blast. Whatever contamination was on the inside of the basin disintegrated and the seam closed. I was now able to continue welding with sterling wire on top of this clean material.

I would never recommend to a beginning welder to attempt such a major step up in milliseconds and power, especially when working with material thinner than .032" (.811 mm). I had been using 2 milliseconds with 50% power prior to the experiment. I would recommend ramping the welding milliseconds and power gradually to see how the metal reacts. What you want to avoid, at all cost, is blowing a huge hole in your piece that will require a major repair.

I have provided a video on making your own coiled sterling wire for Glenn Manning's Speedwire.

The piece below is part of a candelabra. A candle cup broke off of one of the arms and had to be reattached. In this case, I didn't tack-weld both pieces together because soot may have been deposited inside the seam making it more difficult for the solder to flow. I devised a method to hold the pieces together by tacking four wires (prongs) to the bottom of the candle cup. I applied flux inside the seam, assembled both pieces, then pushed the prongs over, securing the arm. This enabled me to rest the tip of the solder wire against each prong when the cup and arm came up to temperature, allowing the capillary action to carry the solder around the seam. After removing the flux I filed off the prongs.

Some of you may be using Lampert's welding wires. I generally use their palladium/silver wire as they're the only company making it. If you're drawing your own wire that's too thick for the Speedwire system, re-use Lamper't spool! I ground away the tabs that hold both plates together, drilled a hole through the inner walls so the wire will stay still while winding, then installed a nylon 1/4" hex head bolt, two washers, and a nut. Voila, a stable method for holding your wire (in my case, below, it's .020"). The nylon components are substantially lighter than steel.

The candlestick below had a stem that was too large for the flexible contact strip to fit around and the other contacts would have left a light mark on this new candlestick. I decided to use aluminum tape to fasten the strip, eliminating the need to refinish the contact area.

10/19/2014: Tool repair. Have you ever dropped a cast iron tool on a cement floor? I have. You cry a little then you reshape it. Or, you braze some brass rod or silver solder to rebuild the tool. Or, you can use your PUK! This cast iron spoon stake chipped when it fell on my cement floor. I used the stainless steel setting on the PUK and rebuilt the missing piece with some heavy mild steel wire, then reshaped the repaired area. (Shown is the welded area prior to finishing). There's no messy flux clean-up and you'll maintain the finish on the rest of your tool – no repolishing. If you have a very heavy T-stake with some porosity, welding will take much less time and without heating a large area with your torch.

10/19/2014: This money clip broke on its spine from too much stress. It was welded back together with palladium/silver wire and built up around the break, adding strength. Welding was the only practical option for this repair because of the inlaid stones. Because of the tension exerted on the spring, silver sheet was welded to the spine for extra support and tapered around the back for a more appealing appearance

If you ever repaired an object containing enamel, you know how difficult it can be, especially if the object requires soldering. You can't use silver solder because of the danger of damaging the enamel. And lead solder won't give you a secure or attractive result, but that's the only method available in your workshop.

If you create or restore enameled objects, you may want to consider a pulse arc welder since the heat is so localized no harm will come to the enamel. This pot needed its handle secured and its dents removed from the single-walled body, double-walled cover, and removeable tea strainer that sits under the cover. There had been a rod extending through both ivory insulators. One end was hard soldered to the handle and the other was peined over on the inside of the pot. Over time, this assembly loosened. I removed both rods then welded new ones to the body, covering the holes. I then drilled holes through the handle for the rods to extend and countersunk the holes. After I reinstalled the insulators over the rods, I attached the handle with the rods protruding through the holes. I then pulsed down over the rods, spreading the silver into the countersinks and securing all parts for an undetectable repair (below).

One of the many strengths of pulse arc welding is the ability to correct mistakes. For instance: you're at the final stage of checking (thickening) the edge of a vase you just spent weeks raising and planishing. Suddenly you discover a stress crack that formed down the side of the piece because the metal became too hard. What do you normally do to repair the crack after you're done swearing? That's right, you solder it or start over with a new piece of metal. The problem is if you use solder, the color difference will stand out like a soar thumb. And this is where welding will save the day. You file a v-groove into the crack and use a wire of the same alloy as the piece itself and fill it in. You've not only saved hours of production time, you've corrected a mistake that will never be detected.

As a restoration specialist, I have been confronted numerous times with this issue. A bracelet or sugar tongs that were flexed so many times a crack developed. Or a spun bowl that wasn't properly annealed when made and cracked on its edge after hitting a tile floor. And that flimsy 18th century goblet that was torqued when hand polishing and cracks opened around its stem. It's very satisfying returning a piece to a customer knowing that a new technology produced a better result.

Are you about to size a ring? Be aware that if you're filling the "V" you made with filler wire will be more brittle than the rest of the ring. And I'm using a ring shank only as an example. On a hardened shank, pulse a couple of layers of sterling in the bottom of the "V" using 2-3ms, thick mode, and 50% power. Add a couple of layers of palladium/silver wire for a stronger connection to the shank and finish off with a thick layer of sterling for a perfect color match.If you find that after welding you have to size up a quarter to one half you should concentrate any hammer blows away from the weld. This will insure that the weld will not split.

Three-knuckle hinges should be easy to make, right? So why do I constantly see them with the center knuckle smaller than the other two? Strange. That center tube MUST be longer than the others so it won't take added abuse.

This 2.75" sterling snuffbox is a case in point. That cover was torn from the hinge. Removing the tight hinge pin would have damaged the outsides of the outer two knuckles. This is where the PUK excels in its duties. Using a triangular graver, I dug a groove between the knuckle and cover on the top and underside. This allowed me to fuse more material between the two components. I wanted to duplicate what would have naturally occurred with silver solder's capillary action drawing the solder between the two components. I fused one thick layer of palladium/silver into the crevices since this alloy would provide a stronger join than sterling. I finished by filling the rest of the crevasse with sterling for a perfect color match to the snuffbox. The images below show the deposited sterling prior to leveling the area.

Below is a fused plate cover to a Matthew Boulton urn. Fused plate (commonly called Sheffield plate), was sterling sheet "sandwiching" a sheet of copper. This was the precursor to electroplating. In order for the cover and rim edges to be connected, a very thin piece of sterling sheet (evident in the image) was lead soldered to the edges, hiding the copper. If I used the same technique to close those edges, the remaining strip may have pulled away from the edge, so welding was the safest and most logical technique to use. I cleaned the area missing this thin sheet and proceeded to reconnect the cover and rim split with palladium/silver wire. It worked brilliantly, as illustrated below. I will top the filler with a heavy thickness of sterling for a perfect color match. This is just one more reason I enjoy using the PUK.

1/15/2014: This money clip developed a stress crack then broke from many years of use. It was welded back together with palladium/silver wire. Removing the coin could have damaged it and brazing the split would have softened the metal with no way to harden the overall clip. Because of the tension exerted on the spring, silver sheet was added to the spine for extra support.

This welder never ceases to amaze me! The perfume bottle top below (actual length 3") was originally a button hook. My customer wanted to use this hook in place of the missing top. I cut the hook and inserted a sterling ball over the rod, then welded it in place with sterling. Pretty straight forward, right? Well, not entirely. You see, the handle was filled with pitch, so the challenge was to weld the ball to the handle without any pitch melting and contaminating the joint. I used a very sharp electrode with a setting of 1ms, thick mode, and 35% power. The heat was so localized that the welding went along flawlessly!

We all have our own techniques when sharpening tools. Below is an image of me sharpening electrodes in a very safe manner. When it's time to sharpen my 80+ electrodes, I do so all at once. I cut a pipe hold-down so I would need only one screw to secure it to my bench over the inset 4" galvanized elbow that connects to my dust collector. I use the diamond sharpening wheel that comes in each package of PUK electrodes. Using very little pressure from my forefinger on my left hand, I quickly "twirl" two electrodes into (not away) the wheel with the thumb and middle fingers of my right hand. Since I'm primarily welding silver and using very little power, I grind relatively slim tapers. Though I have ground as many as four electrodes at once, grinding only two at a time will give you more uniform tips.

I mentioned in an earlier post regarding removing silver solder from a match safe before welding. Though palladium/silver wire may sometimes fill without removing solder, the absolute best and easiest welds are accomplished when solder is not present. Another issue is the presence of a coating over the main alloy, whether it's fine silver or rhodium covering sterling, gold over sterling, and especially lacquer. Always scrape, abrade, or chemically remove this surface in order to work successfully with the underlying alloy.

Today I'm working on a sterling hand mirror which has it mirror-holding bezel lead soldered in place. So, how to remove a handle dent (the customer didn't want any other work done)? In this case, I drilled a hole in the bottom of the handle large enough to insert a burnisher to pop out the dent in the middle of the handle. I then pushed a no-hole sterling ball into the handle and had it drop to the handle bottom, tacking it in place. Below you'll see the ball totally welded in place before I add additional material and blend the handle into the ball.

On objects made of thinner material, it's always best to support the piece from underneath when burnishing so the area won't dent.

Pulse arc welders don't like firestain; it sees it as an oddball alloy and won't react well with it, producing an unsuccessful weld. Remove all firestain from the welding area to expose the pure alloy prior to welding, otherwise, it will be akin to trying to solder over dirty metal.

Here I had a Georg Jensen sterling dinner knife that had been dented on its tip. It was no problem filling in with a .020" / .51mm wire. The resulting restoration is undetectable.

Yesterday I was working on a sterling candelabra that had a candle cup with its internal threads worn down. I used Lampert's palladium/silver wire to fill in the threads and retap the hole. This saved considerable time over brazing a wire into the hole, drilling, then tapping. The reason for using the palladium/silver was because the threads had been hardened from numerous times screwing and unscrewing the cup from its threaded rod. This alloy excels in fusing itself to hardened silver, more so than standard sterling. I then removed the stripped sterling rod from its arm (the bobeche disk is free-floating over the arm), drilled and tapped a hole, then screwed in a new threaded rod before welding it in place with the palladium/silver wire.

The silver creamer below illustrates just how easy and clean it is to get parts ready to braze or solder. A few pulses from the PUK will position the attachment without the fear of movement. No need to worry about binding wire melting or a third hand moving the piece out of place. Tacking this leg in a few spots took only 30 seconds.

There are times when using a glass brush can be messy and even get in the way of a good weld. Plus, the tiny fibers can get lodged in your skin and can be very difficult to find. Today I made this engraving cleaner which will free-up your flexshaft for other accessories. The screw can be loosened and rotated to expose new material.

As with soldering, welding also requires a clean surface. This is especially true with engraving, which can be very deep. When I see oxide build-up (not soot), I reach for the cleaner. The cleaning will also aid in void-free welds.

This rare Jensen piece shows its chased lettering filled with sterling (left). The image on the right shows the finished job. I used 2ms, thick mode, 50% power. The material on this tankard allowed me to use a more powerful pulse. Remember to always start with a less powerful setting so not to blast through the object.

Below is the bottom of a sterling creamer – part of a five-piece teaset that had to have the monograms filled in. The material was too thin to eradicate, and the customer wanted a replacement monogram engraved. See more of monogram filling here.

Top left: I removed all oxide in the engraving with Wright's Silver Polish and a horsehair brush (a typical flux brush). It's best to start with a clean surface. I used silver polish since it's less abrasive than a glass brush or 0000 steel wool.

Top right: the engraving being over-filled with sterling wire (I used these settings: 2ms, thick mode, 50% power).

Bottom right: no trace of the monogram after planishing, abrading, and polishing.

On my PUK bench sits a small anvil for flattening my .010" / .25mm filler wire which comes out of my Speedwire dispenser. There are times when I need a thin piece of sheet to fill a narrow split.

There are times when you'll want to build a heavier thickness on top of what you're welding. Below is a weighted candlestick with the pitch still inside. Previous welds on this piece had not yet been refined, as I simply wanted to get all holes filled first.

I'm using a much heavier .020" / .51mm wire on the edge of <.005 / .127mm sterling. This is a fairly advanced technique, for you'll want to position the electrode on the edge of the wire, pushing a small amount onto the area beneath with a light setting. I'm using the thick sterling setting, 1ms, and 35% power. This would never be enough power to melt the entire wire, but will melt a portion of it. This technique is also allowing for a much thicker base to weld to without blowing through the thinner material beneath. Using a heavier wire will cover the hole much quicker than using .005" / .127mm, and will give me a much thicker base to add heavier amounts of silver. Later burnishing will also result in a smoother surface. Another plus in using thicker material will be found in argon savings.

I discovered this technique yesterday which allows me to free-up my flexible shaft for welding accessories. This $20 Dremel electric engraver, with its 9 power settings, hammers down, massaging the metal while giving a beautiful smooth finish for light filing and sanding. I removed the engraver point, polished the other end, and reinstalled it. The engraver is very loud, so I wear earmuffs. I feel the deposited metal is much less traumatized than when working with many rotary burnishers which "pull" the metal instead of compressing it like a rolling mill.

The area in front of the deposited sterling was finished with a #4 pillar file then 1200-grit wet/dry paper, ready for polishing.

Yesterday I made a hanger for my grinding wheels' truing device. This is an example of successfully welding sterling to cast iron. It's not a pretty connection (I wasn't concerned with aesthetics), though the weld is extremely strong even though there is very little contact between both materials. I used the sterling mode with the thick preset. Periodically removing any soot from the welding area will guarantee a homogeneous meld between weld layers.

I did some stainless welding today with no filler wire. The blade in a dinner knife snapped off its tang. I removed the tang from the sterling handle, welded its circumference, and made it ready for reinsertion. If I had silver-soldered the two pieces back together, there most certainly would have been some etching to the blade from the flux. Cleaning of the tang and welding took all of three minutes!

Up to now I've been demonstrating how fantastic the PUK is at welding silver. You may remember the successful test I performed on pewter. Yesterday I was straightening, leveling, and polishing a white metal sailing trophy. One additional repair was required: reattaching the ship's wheel. White metal generally melts below 300 F (149 C). Since there was a large gap that required filling where the wheel meets the handle, I used some higher temperature lead-free pewter which melts at approximately 450 F (232 C). I used the sterling setting with a time of 1.5ms, thick mode, 35% power. The pewter performed beautifully, filling the gap and leaving a brighter color than a traditional tin/lead solder. (I do no plating, so the pewter color was a great substitute for a silverplated finish. Plus, this was a repair, not a restoration project.) The pewter also gave me a considerably stronger join. Gently bending the wheel back and forth proved the welded areas were successful.

Below is an image of a piece of .040" (1.02mm) sterling sheet that was built-up to a thickness of .105" (2.67mm) using .020" (0.51mm) sterling wire. Notice the lack of voids do to successful melding of weld deposits. I used a setting of 2.5ms / thick mode / 45% power, pulsing over and around the sides of the wire. I then dropped the settings to 1.5ms / thick mode / 45% power, and placed the electrode at a 45-degree angle where the partially melted wire meets the sheet. This allowed the wire to puddle, melding with the sheet and leaving no voids. I then cut a cross-section with a sawblade and finished the face with 2000-grit silicon carbide paper.

When building upon melted wire, make certain that there are no voids underneath, otherwise, the area (when cut on a profile like the piece below), will look like a sponge and will not have structural integrity.

I welded two pieces of .040" (1.02mm) sterling sheet together with .020" (0.51mm) sterling wire, allowing voids (the dark areas of the weld) to develop in the process. I then split the seam by bending, demonstrating what can happen to a joint when not totally filled. Insufficient power was used when the electrode was positioned on top of the welding wire. The result was that portions of the underside of the welding wire didn't fuse to the sheet.

When using a typical 3/4" brass wire wheel in a flexible shaft to remove soot and oxide build-up, use very little pressure and a slow speed. Not doing so may leave brass residue on the piece you're welding and will lead to an unsuccessful weld. Welding doesn't like the presence of an addition metal which isn't part of the alloy you're welding.

Burnisher with slightly flat side, burnisher with slightly flat side, burnisher with slightly flat side, three-sided burnisher, three-sided burnisher, three-sided burnisher.

PUK compactor (teeth were removed, slightly flattened side), four-sided flexshaft mandrel (not pretty, but works well), 45-degree heart bur for cutting grooves, burnisher with slightly flat side, burnisher (top has a slight angle for "massaging" the welded surface), graver for cutting grooves.

This is a double-walled fine silver waste bowl that had many dents. The handles had disconnected from the rim because they were lead soldered. I had to disassemble the inner and outer bowls, remove the dents, reassemble with lead solder, repatinate, and hand polish.

I decided to make a stronger connection where the handles meet the rim, so I welded the dragon toes with sterling (silver soldering would have obviously melted the lead solder holding the two bowls together).

Below is a close-up of a weighted candlestick. The customer didn't want a complete restoration, but to simply repair the stem-to-base connection without removing the dents. The candlestick material was only about .004" (.1mm) thick. I was able to weld the split closed with .010" (.25mm) sterling filler wire using the following settings:

What's amazing is that I didn't have to empty the pitch to perform a successful repair. Upon completion of the weld, I remelted the pitch which filled in any voids around the repair.

1. Grind down the jaw teeth
2. Anneal appropriate diameter brass or copper tubing
3. Force-fit tubing over jaws
4. Use round nose pliers to crimp new non-marring teeth
5. Roll over tips so they touch
6. Flatten and weld corners of tips
7. Slightly round tip corners
8. Polish tips

Filling in dents and welding cracks. I have the trophy sitting on a rolling pneumatic table that can be height-adjusted. I constructed the table out of an old office chair, removing the seat and replacing it with a piece of plywood.

This Kiddush cup was made from very thin material. I reshaped the torn area which extended 3/4 of the way around the stem. I then brought together both sides of the split and welded them together. All voids were filled by welding with sterling wire for a perfect color match. I straightened the stem and leveled the bottom and top rims. I then removed the dried polish and performed a very light hand polishing.

5/10/2012: Welding Objects That Flex
I often receive broken sterling flatware for restoration. Welding these stamped (hardened) pieces back together will result in cracking on either side of the weld due to the flexing of the utensil. This is due to differences in grain structure of the stamped object and the welded filler wire. I recommend using a mini-torch and annealing the very edges of the break. Then file a v-groove on the backside of the break and use filler wire (e.g. sterling for a sterling fork) to fill the groove. This technique makes for a homogeneous connection.

There are many things about the PUK I enjoy. One of those features is the very low argon consumption compared to other systems. I find that I can perform 99% of my welding using only 1.5 liters per minute (lpm).

This is going to blow you away! A friend came to me with an amber and sterling ring. The amber was glued into the setting with decorative wires above, only 1/16" from the amber. As you can see below, the wires had come apart. So, I couldn't remove the stone, and was forced to weld the wires back together (I would have chosen to weld them regardless of whether or not the stone could be removed). If I had used a laser welder and missed the mark, the stone would have fried. But first, I wanted to try the technique I was about to use on a sterling jump ring surrounding a piece of plastic. It worked - no harm came to the plastic. Here's the procedure I used...

The wires were then sprung back together. As a precaution, I slipped four layers of index card stock between the wires and the amber to prevent the stone from burning.

Below are the wires reattached with sterling filler wire. I used the filler setting with 1.5ms and 30% power.

This box cover's four corners were all split. I used sterling filler wire on the inside and outside, then compacted the material from the outside to remove any porosity. What appears to be a corner split in the third image is actually a reflection

This bracelet wasn't the thinnest piece I repaired with the PUK, but it did present a new issue: How would pulse arc welding hold up to constant bending?

The split was thoroughly cleaned, then beveled on the back side. I used .010" sterling filler wire and over-filled, spreading and smoothing material on either side of the break to strengthen the area. If I had not added additional support, I would see this piece back in my shop in a short time. I didn't totally compact the filler metal as it would have become too brittle with the possibility of the split re-opening. I decided to simply burnish the surface to remove any surface porosity. This left the filler material a bit more flexible.

Someone had the clever idea to engrave these 1730 caster bodies with "salt" and "pepper." (The tops were left off to show a larger area of the engraving.) Engraving the function of these pieces is certainly not something I would have done, but to each his own. Since the silver was too thin to remove by filing, I used the PUK and sterling wire to fill it in. When I photographed the "after" image I had not yet polished the bottom sections of the casters.

This 5½" Wallace sterling cut glass jar cover was stamped and spun out of extremely thin material. The image on the left shows light coming through three areas of a flower as well as other areas on the piece. These areas were worn through from over polishing. The edges of the open spaces were the approximate thickness of a piece of tin foil (.001"). The PUK worked beautifully, and I used .25mm sterling wire for a perfect color match.

Question from jeweler: I recently purchased a PUK Pro welder and am contemplating a retipping of a Tourmaline. I've completed several successful repairs upon Diamonds and Rubies but haven't worked on softer, heat-sensitive gems. Can you share any advice or point me in the direction of any technical material?

Answer: Tourmalines are inherently fragile stones. Having said this, there should be no problem rebuilding a prong. Firstly, it is advisable to try this technique on a practice setting holding a faceted glass "stone." Use 36-gauge annealed wire (.005") and the lowest possible power setting on your PUK when welding. Welding from the outside of the setting (don't let the electrode pass over the glass), build the prong straight up with the filler wire. When you're happy with the height of the prong, finish it and gently push it over the glass.

I did a comparison test using .030" (0.76mm) sheet standard sterling and Argentium. I used the gap mode with 6ms and 45% power for both alloys. The standard sterling (left) had smaller and slightly rougher welds than the Argentium, and demonstrated more oxide formation. The actual weld diameter sizes were .030" (0.76mm) for standard sterling, and .040" (1.02mm) for the Argentium. Dropping the power to 30% when welding the Argentium gave the same size diameter weld as the standard sterling.

Conclusion: Argentium gave a cleaner and smoother weld with 30% less power consumption as compared to standard sterling.

Today I experimented with welding metals other than the sterling I normally work with. I cut some lead-free pewter sheet that was .040" (1.02mm). I filed the edges of each sheet 90 degrees to make a butt joint. I then used the PUK's gap filler mode with a setting of 6ms and 35% power, running down the center of the joint and overlapping each weld 50% I welded the top and bottom of the joint, with sheet penetration of over 50%. I then sawed through the joint and used 1200-grit silicon carbide paper to see if there were any gaps and found none. I folded the sheet on the joint in half from front to back, then back to front, and found no stress cracking. I continued the folding back and forth which eventually resulted in joint failure. This was because the joint was more brittle than the rest of the sheet. The same failure would have resulted if I had used pewter solder.

Since I was in an experimenting mood, I used the same PUK settings and welded the pewter to the aluminum backing of a safety edge blade with excellent results. The aluminum was then welded to the steel blade - this, too, was successful.

This problem normally would require me to remove the plaster from the handle making sure it's perfectly clean before brazing. I would then have to go in with a scraper and clean around the split to guarantee a successful brazing job. Most handles I repair contain pitch which would have to be fully emptied so to not contaminate the joint (Arc welding and laser welding would have produced enough localized heat to melt the pitch, contaminating the seam.) For this handle, I experimented by removing only the plaster that was attached to the underside of the ragged split (approximately 2" in length) and left the remaining plaster in the handle. Also, I didn't remove the solder from the seam - arc welding and laser welding technology normally wreak havoc when working with solders, but I was curious to see if the PUK would give me a different outcome. I cut a piece of annealed .005" sterling sheet and used it as a shim in the split, exposing about a 1/16" above and below the surface. I then clamped the two sides together and began welding using the PUK's gap filler mode. Positioning the electrode on the top edge of the shim, I was able to melt and "push" the sterling down into the split, successfully filling the most of the void. This process is completed within milliseconds. I then used .010" annealed sterling wire to fill any remaining voids. The end result displayed absolutely no porosity and was undetectable. There was no firescale or firestain to remove, no patina to be reapplied, and a seam that would never split again.

Avoiding Pain When Welding for Long Periods
Les Hubert, Licensed Massage Therapist

The job of a silversmith or any other metal worker demands precision. And this comes with a price if the artisan's hands and arms are called in to provide that precision. With the cooperation of silversmith Jeff Herman, I was able to observe just such an occasion. Jeff informed me that he had been experiencing forearm pain and that this occurred during and after intense concentration with the use of a pulse arc welder. In order to use this device correctly, one has to hold the object being worked on prolonged periods with micro movements. In the following photo, the red ellipse indicates where his pain is located. This pain is caused by a condition called lateral epicondylitis, commonly referred to as tennis elbow.

In this particular case Jeff is asking his muscles to make constant micro movements, where they are at a disadvantage after prolonged periods. Muscles need to adequately contract and elongate in order to pump out fuel waste and bring in fresh fuel. When they are unable to do this, lactic acid builds up in the muscles and connective tissues, creating micro tears. To illustrate, imagine an elastic band that has been burned. Instead of elongating when stretched, its fibers will simply separate and tear.

Below is a video of welding a large object illustrating micro movements of the arm.

With this condition of tennis elbow, one can also find pain leading to the thumb because of the radial nerve that lives in the area between the larger extensor muscles of the forearm (see diagram).

If you are already having problems with these areas, I suggest getting treatment with a licensed professional such as a massage or muscular therapist or physical therapist as soon as possible. If that's not possible in the immediate future, then ice should be applied to the affected area for at least 20 minutes (see photo to right).

Then remove the ice and move the forearm slowly in a circular motion (demonstrated in the video below) for one minute. Repeat this process two more times.

Cryotherapy or ice therapy can quickly help control swelling and pain. Combined with movement it can aid in removing some of the scar tissue in the affected area, thus allowing the body to replace the scar tissue with new and healthy fibers.

When your work demands a steady hand, give yourself plenty of stretch breaks. Every half hour isn't a bad idea. Try mildly ringing out a towel, raising and lowering a weight (I used a sledge hammer that has a hanging hole in the handle), or squeezing a soft ball to aid in lactic acid release.

Try to keep in mind that your body has limits of endurance. It's an incredibly complex and beautiful organism. With your help, as with any tool, if properly maintained, it will continue to serve you well for many years.