of teddy bears and gold soldering

[iori]

Went up to Cooksons a couple of days ago and exchanged a handful of notes for a thimbleful of gold (not really a thimbleful, much less ), a few small tools and they threw in a teddy bear & a
lolly. Being 75 I've passed on the teddy bear ( I'm more into meercats actually ) and am looking forward to the lolly, that is unless my thieving labrador gets it first ( and he will, he will). The gold has presented me with a different set of problems i.e.-its annealing and soldering. This is my first experience with solid gold and I think I rather expected it to be similar to silver,I'm making a ring for my wife's birthday, I have already designed and made a prototype in brass and I dipped into one of my books to check on its annealing ( 9ct yellow ), said book told me to heat to red and quench, which I did and aquired a blackened piece of gold which had no discernable difference in its hardness. I have since found out that that particular method could have resulted in its shattering, which no doubt would have left me in the same state !
A different book tells me. that to anneal requires slow cooling and that dipping in a mixture of boric acid ( haven't got any ) and alcohol will guard against the oxide forming. Done the first but not the second. Will coating the whole ring in borax do the same thing. Should I have attempted to anneal it at all or is ,as is bought, 9ct. yellow gold much less malleable than say brass or silver? So to the rituals of soldering. Let's say that I have the ring secured vertically with tweezers ( in a third hand ), covered in borax, except for the seam which I have Aufluxed, a microgram of hard gold solder poised precariously in its appointed place,a few candles is all the light I have, tubular bells plays in the background, I have sent my wife, the dog and the cat also
out of the house. I am alone, torch in hand, is there an incantation I should use?
What can go wro...............
yours
iori

[Dennis]

Iori, you've done the incantation, so now just go for it. It is not so very different from silver, except that being a poorer conductor it does not lose its heat as easily. Make sure the ends to be joined are bright and clean and solder it in subdued light so that you can see if you accidentally overheat one area. I would skip the preventative borax when soldering, because the solder might skitter all over the place instead of being confined to the join. When the gold is at soldering temperature it will be a dull red, so pull the flame away as soon as the join is done. Then let it cool a little and drop it into your heated pickle. Shortly any discolouration will have gone.

Traditionally jewellers solder on a charcoal block for gold as it gives a reducing environment, but I don’t think this is essential. Let us know how you get on, Regards, Dennis.

Boric acid, or boracic acid should be available from you local chemist in small quantities, as I think it is used for surgical dressings. A saturated solution in meths (or vodka) can be brushed onto warmed metal to reduce firescale formation prior to annealing, but keep the bottle and any spills well away from open flames.