Most stud welders are essentially capacative discharge welders. They
charge a large (and fairly expensive) bank of capacitors, then when you
push the button the power to them is disconnected from the supply and
they discharge through the stud to the workpiece. Capacitors discharge
AC so 99% of these machines are AC welders. Generally there is a
projection on the stud that hits first so that the arc is controlled to
form a molten pool of metal which the stud is pushed into. Sometimes
studs come with a flux ring in place around the projection to improve
things.

If you don't want the cost of a stud gun or rental on one, why not just
practice being bad at welding? It would seem that you could take a
simple AC buzz box and then attempt to make your electrode (wire or
whatever else you choose) stick to the base metal. With a pinch clamp
type electrode holder, you should be able to let go of the electrode
right away after it sticks. Get the amperage right for sticking and you
may get enough penetration that it will get the job done (at least the
damned things stick too much when you don't want them too!)

Koz

Grant Erwin wrote:

Back when I used to work in ships ('70s) I used to see the insulation guys
laying out large numbers of stud locations, then the welders would move in
with their stud guns and weld studs everywhere, then the insulation guys
would use the studs to hang insulation on the steel bulkheads and
overheads.

Now I want to make a clamshell forge, and I figure I'll need a few dozen
studs welded into the "shells" and wired together with heavy wire to keep
the refractory in place. I don't own a stud gun nor, with the exception of
my shipyard experience, have I ever seen one. I remember them being
sort of
like a spot welder except they were designed so you put a stud into
the gun,
pressed the stud where it needed to go, and pulled a trigger. A big bunch
of sparks flew out and bobs'yer'uncle.

Anyone know anything about stud welding?

Grant Erwin
Kirkland, Washington