Our guest writer today is Jeffrey Herman, an internationally renowned silver restoration and conservation specialist, and founder of the Society of American Silversmiths. Jeff kindly took the time to write about the PUK04 Arc Welding System, an incredible tool and a huge asset to anyone’s workshop. Here’s Jeff:
As any silversmith knows, silver solder is the ideal material to use when joining sterling 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 visibly 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 use the PUK04. Pulse arc welding allows me to use solid sterling wire for a perfect color match (silver solders contain less fine silver than sterling).
Since I work on larger objects, I purchased the optional articulating arm. And, I added the argon regulator, which is extremely accurate.
The pulse arc welding principle: non-toxic argon gas is pumped through a handpiece and engulfs the welding area with a protective atmosphere to eliminate firestain. An electric arc (energy flow) is created from the point where the electrode touches the workpiece. As the electrode retracts, the arc is drawn up from the point of contact. Exactly here, melting occurs, and the result is a clean and stable weld.
The high degree of precision is made possible by touching the workpiece with the tip of the electrode. The electrical arc necessary for welding is thus generated from exactly this point. By varying the angle at where the electrode tip touches, welds can be accurately steered in the desired direction and previously applied metal “distorted” or modeled. The heat is so localized that I can handle the object without getting burned, even at 1,640 degrees—the melting point of sterling!
- 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 thin as .001″
- No firescale or firestain due to 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 and ergonomic for work efficiency
- Maintenance-free, small footprint, and very low cost of consumer materials (electrodes)
- Extremely low argon consumption (I use approximately 1.5lpm)
- Touch-screen operation
- Easy-on, easy-off handpiece nozzle when changing electrodes
- 3-year warranty
- It’s a beautifully built piece of equipment
For additional information and examples of what can be accomplished with the PUK04, visit my PUK review page on my site.