Posts: 200
Threads: 4
Joined: Feb 2012
Location: Tyler, TX USA
Get some Engelhard Ultraflux, and use something like Aufhauser silver alloy A56-T or similar. Try to avoid the cadmium bearing alloys if you can. If you have trouble sourcing this stuff, hit your local HVAC house and get silphos or one of the copper/phosphorous alloys. Plenty strong, but you need a 0.002/0/003 gap or so. And clean. Acetone is good for cleaning.No side effects, but don't use wife's nail polish remover, it has oil content. Don't make the two surfaces to be joined too slick. A 16 Ra finish won't bond as well as a 125 Ra, so rough it up a little if you have to polish it to size.
Posts: 535
Threads: 39
Joined: Jan 2013
Location: Kelowna, BC, Canada
I've done silver soldering for quite a few years, long before I got an O/A set. For slightly heavier pieces, I often used two regular propane torches. When the whole thing is hot enough, set one aside and keep everything hot with just one while you flow in the solder.
+1 for Tony's comment on Cadmium-free.
Mike
If you can't get one, make one.
Hawkeye, proud to be a member of MetalworkingFun Forum since Jan 2013.