PUK 4c Pulse Arc Welder

I have noticed several suppliers advertising the Lampert PUK 4C as if it were a new model at an attractive price. Does anyone know if it is a new model or re-release of an older model? I am also interested in general information about how the PUK 4C would perform on heavy sterling silver pieces. Thanks in advance for any information…Rob

Hi Rob,
Last year I researched this metal joining kit in depth.
I spent a whole day with their UK agent running just about every possible trial on 999 silver and other metals to see if it would do the following.
Join at point contact .5mm die struck little leaves in 999 Ag, some 10mm by8mm prior to high temp enamelling.
The over riding problem I found why it wouldnt do this was the very high thermal conductivity of the metal.
It just wouldnt fuse.
I then sent the identical samples to Lampert in Germany for them to try to do this. Their results were fair but still not good enough for the durability of the product.
Now it works well on low conductivity metals, like s/steel iron etc and some gold alloys.
So will it work on heavy as you say sterling?
My guess is no. Most users of this kit use it for tacking products together prior to normal brazing.
I finished up using an 18ct white gold brazing paste that has the highest melting temp of all white solders.
The real expert with Lampert kit is your own Geoffrey Herman who will probably help out more than I can. Maybe he might run some trials for you ? So if he can get the results you need then your in business.
What are the weight sizes? of heavy sterling you want to join?

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I am no expert on Pulse Arc, but I do have roughly 20 years experience using Laser Star laser welders.

A couple years ago I visited the weekend long Bench Jewelry Conference that Stuller held, and I did one seminar on the Puk Welder. I then sat down and played with the Pulse Arc machines that they had available, and I was pretty impressed at what the machines were capable of.

After several test runs, and admittedly, with the sales folks for the Puk looking over my shoulder I rechanneled an opal inlay, Sterling Silver ring, with good results, and no damage to the opal.

While I am not about to run out now and purchase a Pulse Arc machine, I do think that I could learn to do nearly every kind of weld that I now can do on the laser, with Pulse Arc, BARRING (and for me this is an important distinction!) welding deep inside crevices, holes and under galleries, which the laser excels at.
The arc will always take the shortest path, so welding in deep recesses will not be possible with the Arc.

Were I just starting out, I now think that I would opt for the Pulse Arc, and just send some of the more difficult and specialized work to a Laser Welding Jeweler.

One technique that I use daily on the laser is tack welding parts in place, and then going to the more traditional torch to complete the joints. This eliminates the need for clamps and jigs, allows me to fine tune, adjust, pieces prior to soldering.
The Pulse Arc would be just as effective at this, I believe.

I have PUK 3 and this is exactly what I do with it. A very handy tool for welding jump rings shut and tacking pieces together for soldering. It is possible to retip on heat sensitive stones but can be risky. I have used the Orion machine as well and it is a little better. But I am not going to size a ring with either one of them. And I am not overly impressed with sizing done with a laser.

The only rings that I routinely size using the laser are Platinum. The current trend of setting gemstones quite a ways down the sides of the shank make torch welding Platinum just too risky.
One or two stores that send me work will request that I use the laser to size a Sterling Silver ring, but generally I prefer the torch for sizing rings, over the laser.
The Laser is just one tool, it does some things far better than a torch, andsomethat a torch simply cannot do,while the torch is the better choice for many other operations.

I will say that I do think that a skilled Pulse Arc welder operator could also do a great many of the operations that I reserve for the laser, but neither tools can replace good torch technique for much of what comes across my bench, imo.

I had a 4.0 PUK and recently upgraded to a 5.0. Since I work mostly in silver, the 5.0 has made a huge difference. The 4.0 was fine for jump rings and light tacking but the newest one has the power for easy use with silver. I also like the user interface on the 5.0 - intuitive. And less money than the 4.0 by $1000.

I have been using the PUK to size rings with no problems. We just opened a second store and have a PUK 3 (the older jeweler at the other store hates the laser so I, being the hip new kid am supposed to get it, but the new store doesn’t have 220 so I’ve stolen the PUK) and so far I love this thing. I’ve used two different lasers over the last few years and am really struggling to find situations that the PUK can’t do what the lasers could. I haven’t tried to size a silver ring yet, though, so I may be counting my chickens before my eggs have baskets or spilled milk or something.

If it were my money, I would definitely not by a laser, but certainly wouldn’t buy a PUK, either. I would buy an Orion. There is little to no information available on the PUK. Orion, on the otherhand, has people who have actually given me advice on using my PUK.

Anyway, that’s my two cents.


What problems are you having with sizing?

Hello everyone!

I can’t imagine most users are using the PUK for just tacking.

If anyone is having trouble welding sterling I’ll try to help. But first, take a look at my PUK blog here: Society of American Silversmiths - PUK 5 and PUK Pulse Arc Welders Reviewed, PUK04 Review. If you have questions you couldn’t find answers to, ask away. Sometimes it may be the settings you’re using. Perhaps the electrodes aren’t sharp enough. Maybe your argon pressure is too high or your suction is drawing the argon away from the piece you’re welding.

I’m all ears,


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Hello Brice,

There’s a wealth of resources provided by Lampert to help you be a better welder. Here’s a FAQ page on their site: FAQs on precision welding | Lampert Werktechnik. And here you’ll find numerous PUK welding videos: https://www.youtube.com/results?search_query=lampert+welding. And of course there’s my blog: Society of American Silversmiths - PUK 5 and PUK Pulse Arc Welders Reviewed, PUK04 Review. In North America, technical assistance via phone and e-mail is available from Lampert Tools USA, Inc., Robert Sepiashvili, 866/478 – 5111, info@lampertusa.com.


Well, that’s just incredible, I’ll be up all night now! At least I’ll have plenty of crow to snack on… Truly, thank you for the information! Im still new to the machine, but I’m like it more and more every day.

Too much porosity and it is so slow.

Hello John,

Porosity from laser and pulse arc welding can’t be avoided, though, it can be reduced. John, are you getting any center-line cracking when you weld? If so, that would be a huge contributor to major porosity as well as joint failure. Are you able to take a close-up picture of the weld?

With virtually all of my welds I must burnish the surface to compress the porosity. I can hand burnish or use a rotary burnisher depending on the weld. The metal is heated and cooled, just like casting. The same goes for these forms of welding.

I don’t recall if the PUK 4c has a higher speed setting, but the PUK 5 does.


Yes I have had cracking. I find the welds to not be as strong as a solder joint, nor as neat.