For example, how do I solder something with epoxy or pearl, or
amber in the design when these elements can not be removed and then
It depends on how much heat gets to epoxy, pearl or amber; too much
and its destroyed. The PUK doesn't solder, it welds, and although the
temperature at the weld point is very high it lasts for only a few
milliseconds and thus is very localised. So localised in fact that
its quite feasible (common, in fact) to hold the item with your
fingers just a millimetre or so from the joint. You just can't do
that with solder because the spread of heat is needed to allow the
solder to flow nicely. Like all welds, the actual joint is rippled;
not smooth like a soldered joint. You don't get nice fillets with a
weld, and the PUK is very poor at filling gaps - it is possible with
the use of filler wire, but is hardly worth the trouble (maybe those
who are more expert would disagree). If a smooth joint is required
from the PUK then you have to dress it afterwards.
Anyway, another question for those who like the PUK - are you
working with argon gas or without? if you are working with gas,
where is the gas connected and how is it fed to the working tip of
the welding hand piece? And is there a huge difference between
working with or without gas?
I use argon; as the makers recommend. The gas is fed into the rear
of the control box and then through the umbilical cord that connects
to the hand piece. When the needle electrode touches the work piece
you first hear the gas coming out around the electrode, then the
"puk" sound (that gives the name of the device) as the arc is struck
and the electrode automatically retracted. I've never used it without
gas and I would imagine that, if I did, the welds would be very poor
- rather like soldering without flux.
As others have said, the PUK (and lasers for that matter) shouldn't
be regarded as a substitute for soldering - its another method of
joining metals and is best regarded as an additional tool in the
armoury rather than a replacement. There are some jobs that are quite
impossible with normal soldering, but trivial with the PUK. Some
metals, such as titanium, are all but impossible to solder, but can
be joined easily with a PUK (or laser).
Like all metal working techniques, you have to climb a learning
curve before you can use a PUK (or laser) properly. The supplier from
whom I purchased mine ran a one-day course, the price of which was
refunded if the PUK was purchased. Maybe you could get the same deal.
Regards, Gary Wooding