I was lucky, and got a spot-welder from a dental laboratory which
closed down. From some testing, I can say it works, but there’s a
but: It works well for all materials I have tried so far, except
silver. Silver just won’t really fuse at any gauge. I tried water,
salted water and flux as electrolyte to improve the weld, but I never
got a reliable fusion.
Is it the silver’s physical properties that are not suited for this
type of welding, or am I doing something not as I should do?
Silver is tough to spot heat because it conducts or wicks heat away
so well. You have to pump more BTU’s into the area then you are
losing to the edges when you braze, weld, fuse, etc. Silver even more
so…
silver, like copper is an excellent electrical conductor so you will
probably have to adjust the setting on the spot welder to get a good
join because of a lack of resistance to create the heat. Rough the
joint up with emery and try again with varying current and time
settings. Clean between each attempt so you are always using the same
conditions.
No matter what process is used (laser, TIG, torch etc) silver is
possibly the most difficult metal to weld due to its high thermal
conductivity and electrical conductivity. Even folks with the super
duper top of the line lasers have difficulty welding silver. There
is not really any way to get around this. So use your neat new welder
for everything but silver and continue to solder your silver.
Jim
James Binnion @James_Binnion
James Binnion Metal Arts
I have used TIG with great success on silver. The beauty is in the
avoidance of fire scale and pitting of a fused joint. The trick here
is to be courageous as very high amperage is sometime required. This
repair was made with the turquoise packed in heat sink gel and the
machine set to spot welding mode at 300 amps for 1/10 of a second.
Take a look at
I’ve added images of a silver charm project to my site. In this
project I used a piece of bar stock I had on hand to roughly produce
a pierced plate for a charm. There was little waste of material. I
spent no time assembling the plate. Much of the work was done with
sprue cutters! It did save some time not having to drill a hole in a
large plate and cut the center piece out. I didn’t have a large
plate anyway, so I worked with what I had! This project demonstrates
the ability to produce defect free silver TIG welds. Take a look if
you have a minute. There’s a link at the bottom of my TIG welding
page. I received a Miller Maxstar150 STH and Maxstar 150STL to play
with. They are far more capable than I imagined for such small
dimensions (H:9 in W:5.5 in L: 13.25 in 13.7 lbs.) I’ve carried
bigger lunch boxes!
How is the tig welding for less pure alloys 10, 14k white and
yellow. And how is it in heavy pieces with sensitive stones? Thinking
school type rings and some yurman pieces. I would assume clean up is
easier than after cooking these types with a torch.