Back to Ganoksin | FAQ | Contact

9K Gold solder pitting problem


#1

Hi everyone

I was asked recently to construct a ring for a friend of mine which
was made up of a 9ct band with two 9ct square wires soldered on to the
surface of the band at the outside edges and a single silver square
wire in the centre which created two channels on the surface of the
ring. Inside the channels I was asked to put 2 twisted pairs of round
fine silver wire which were not to look as if they had been soldered
onto the surface. Simple enough, but the ring was designed as a thumb
ring with a split in the band for expansion over the thumb joint, and
the two ends created by the split had to have 9ct gold caps on them.
I finished the project and the result looked great except that the
outside edge of the ring showed some very small pitting which appeared
on one of the solder joints. I believe that this was caused by the
fact that I had to reheat the ring on several occasions in order to
use different temperature solders so that I did not run the risk of
damaging any of the individual ring components. Unfortunately, the
pitting is not shallow enough to remove by sanding and repolishing as
this could end up distorting the symmetry of the ring.

The pitting I have described is very minimal and almost unnoticeable
but I know its there and I will therefore have to point it out to my
friend. My question for the group is whether there is a way to fix the
pitting without damaging the ring and having to do it all again. I
have thought of using a thermal paste to cover the ring with the
exception of the pitted area and to use a solder pick to place a tiny
ball of easy gold solder on the affected area and flood the pitting
before repolishing the edge, but I am not sure whether this will work
and do not want to risk further damage and possibly additional
pitting.

Does anyone have any ideas?
Kind regards
Julian Paxton


#2

Julian Paxton’s pitted solder problem is much less likely to occur if
he uses hard solder throughout, rather than graduating to medium, or,
worst of all, easy. He can rest assured that, if he has planned the
sequence of operations and is reasonably careful, the work should not
collapse - the hard solder left from a previous join will not melt
again at quite as low a temperature on subsequent soldering with the
same grade of solder. 9 ct easy solder always seems to pit a bit -
possibly because of the zinc content needed to lower its melting point
sufficiently. This is why I try to avoid it. David Kelsall