Soldering 10k Gold

I need to repair an old 10k yellow gold ring shank. I can easily get
8k yellow gold solder but cannot find a source for 10k yg ring shank.
Does anyone know of a source. Can 14k be used for the new section of
ring shank? This isn’t much of a ring but holds great nostalgia for
my brother-in-law.

Any help/tips most appreciated!

Unless you suspect the prior use of lower melting solders, there is
often little reason to use a solder as low as 8K. these repair
solders may melt at lower temps, and cost less, but they usually
don’t match the color so well, nor are they as strong, and they’re
much more prone to tarnishing / discoloration. And they can cause
problems the next time the ring needs repair. if at all possible,
use a 10K solder, or even 14K solders to repair the 10K shank.
Remember that solders come in both repair grades, and manufacturing
grades. The manufacturing grades of solder contain the full karet
content of the gold they are marked as, which repair grade solders
are lower. So a 10K repair grade solder will already be slightly
lower in actual karat than 10K. if you drop to a solder marked 8K,
you’ll likely be getting a solder who’s actual karat is not much
above 6K… And personally, I’d recommend actually using the
manufacturing grade of solder if you can, and if the metal being
repaired doesn’t have obvious signs of prior repair. If you’re
worried about melting the gold by accident, then just use an easier
melting grade of solder rather than the lower karat marking.

If you cannot find 10K gold to use for the repair, there’s no
functional reason you cannot use 14K, other than the fact that it
costs slightly more, and the color match may not be as good. You
certainly won’t be the first repairman to use 14K to repair a 10K
ring due to the lack of 10K stock on hand. If you wish, you can
always alloy down a bit of 14K (add the appropriate amounts of an
alloy composed of two parts copper and one part silver, or better
yet, that same alloy where a little bit of the copper is supplied by
a bit of brass (to add a little zinc, which the 10K no doubt has in
it) The only downside to that is likely you’ll then have some left
over 10K which you might not need in the future…