I’m not sure that it is the pick per se, as I find that I am able to
burn holes in my sheet, with the darn solder itself (so, obviously,
newbie here trying to get solder to melt, and I am focusing too much
in one spot).
You might want to try paste solder as the flux is already in the
formula. You can place the paste exactly where you want it or you can
also use for sweat soldering, or pick soldering It is the heat of the
metal that heats the solder, gets it ready to melt and flow and not
just the flame.
In the case of a bezel, solder the bezel with the highest possible
temperature for formula of solder (hard #75 or medium hard #70).
Since it is Argentium, you may have to go down a grade of solder from
what you might normally use since Argentium melts differently than
sterling or fine silver. Then, making sure the bezel is totally flat
and exactly the same contour where it meets the back sheet, place
some of the paste solder on the inside of the already soldered and
fit bezel on the bottom inside, making sure that the solder is all
around the inside of the bezel. If it is a small bezel then very
little solder spread all around the inside of the bezel, etc. Place
bezel on the back plate where you want to have it attached (soldered
on). Put heat first on the back plate, not directly on the bezel. The
paste solder will start to activate and smoke or in some cases a
small flame will emerge. Continue heating the back plate, moving your
flame all around to heat the entire piece evenly. Do not stop in one
place with the flame as that will cause the holes you are describing.
Keep going round and round on the back sheet and/or back and forth.
Continue heating until you see the shine of the solder, at that point
you bring your flame closer to the bezel and draw out the solder to
the outside bottom side of the bezel and attached to the back plate.
Do not move the bezel, let the heat do the work of bringing the
solder into the correct place. Let cool. All soldering take
practice. You need to know how much product you need to use… little
line, medium sized line etc. to accomplish the project at hand; or
how much of a ball you need to create with a pallion and paste flux
before you will be proficient. So, the old adage always comes to
mind. Practice, Practice, Practice.
You can use brass sheet and work with that as it acts much like
silver and will not have the great expense of silver itself. Just a
small amount of solder goes a long, long way.