I admire your willingness to ask the question. It demonstrates a
willingness to learn and continually improve your skills which gives
us the only real competitive advantage any of us can have.
This is very hard for anyone to put their finger on without watching
you do it and then picking apart your technique. I’ll give you a
little input, for what it’s worth. I’m assuming these are gold
solder joints. Please don’t be insulted by any of this
over-explaining, you probably know everything I’m about to say…but
maybe there is one little thing that might help you.
-If there are pits in your seam and your seam is as clean as you
describe, I would think you might try a softer flame and let it flow
a little longer, then let it go a little longer still. Sometimes you
will see little bubbles popping on the surface as they float out of
the molten solder. It sounds like an incomplete solder joint. It’s
possible you’re doing it too hot and too fast.
-We did have a guy in the shop who liked to use borax cones and was
have trouble with his seams as well. I asked him to switch to
Batterns flux and it cleared up his problems. I know there is
absolutely no problem with the cones, it was just a variable to
remove and it worked.
-If it’s white gold your having issues with, try using 20K white
weld. You’ll need to use a softer flame, you may need to start by
heating the solder more directly than usual, rather than from the
opposite side of the seam to get it started but you can then pull it
through the seam normally. You’ll want to let this flow longer than
you might normally…but careful not to melt the shank. We have very
few pitting or cracking issues when we use the 20K white.
Just for shop talk purposes and to help you pick apart your
technique, our procedure for soldering an average gold ring that we
are sizing down (forinstance) is this;
-Clean the ring.
-Cut out the piece with saw.
-Bend the shank together with 1/2 round pliers while being careful
not to deform or damage the ring in any way.
-If needed take a saw cut through the seam to true it up and then
bend it closed again.
-Put the top of the ring in cross-locking spring tweezers with the
seam up and the top of the ring down. Put the end of the tweezers
under your bench block.
-Cover the ring with boric acid and alcohol, light it to burn off
-Pick up you piece of solder with your pick-up tweezers and dip it
into your nice clean little puddle of Batterns flux. Set it on top
of the seam.
-Set your flame on the soft side, but substantial enough to get the
solder to flow in a few seconds.
-With your clean solder pick in one hand and your torch in the other
begin heating the seam from the inside of the shank. Use the pick to
keep the solder from popping out of place as the flux evaporates.
-As the solder balls up, without removing the torch, you might use
the pick to position the solder ball over the seam. But it is likely
your picks work is done.
-Continue to heat the joint in a way that the solder flows freely
and equally on each side of the seam and draw it through to the
-Pick up the tweezers in one hand with the torch in the other and
heat the back side of the seam in needed to draw the solder
(normally not needed).
-If it’s not flowing, something is wrong, likely dirty. Stop and
pickle and possibly hang in the sonic. Try again. If still not
flowing…something is on there that shouldn’t be. Might have to cut
through the seam and super clean it…and try again.
Sorry so wordy. Hope it gives you something to try.