Make sure the joint and catch are flat on the bottoms by sanding
them. Use sandpaper (320 or 400 grit) on top of a piece of window
glass, rub the catch and joint in a circular motion on the sandpaper.
Rinse them to remove the residue.
Use water-based correction fluid or ochre to coat the catch
mechanism. Make sure you get it inside the little wheel part. This
will prevent solder from wicking up the catch and freezing it. Dry the
coating well with a soft flame. Make sure there is no residue on the
bottom of the catch.
Coat your main piece with a fire scale inhibitor and dry it with a
soft flame. Add a little flux where your catch and joint will be
placed. Dry it with a soft flame enough so it is no longer bubbly but
has not yet gone to the liquid stage. The flux should be fairly flat,
but still white.
Put on a small chip of solder on top of your fluxed areas. Bring your
piece up to heat just long enough for the solder to slump, but not
flow. You want to wind up with a little bump or pimple of solder.
Now set your catch part up in the self-locking tweezers. Run your
flame around the solder on the one end you want to attach the catch
part, while at the same time holding the catch in the flame to
pre-heat it. When the solder flows, drop the catch down into the
molten solder with a fluid motion. Bring the flame up to concentrate
it on the catch, but keep it moving so you don’t overheat the catch.
As soon as you see the join completed, blow on the catch to cool it.
One quick, strong puff will do it. Now do the same for the joint
There is no substitute for experience. Practice with a couple of
little pieces of copper about 1" x 2" and some of the cheap pin sets.
Practice with the joints first, doing 10 of them. Another piece of
copper and practice putting on 10 catches. Another piece of copper,
and practice putting on both sides of the set so you can control your
flame without flowing the solder on the other pieces and upsetting
them. A couple of dollars and a few hours will be all you have to put
out to become expert at it.
Hope it helps. K.P. in WY