Thread: Silver soldering / brazing with propane

Attempt 2 with the same solder and flux was not very successful. Same flux problems - the flux is all burnt away in seconds leaving a black surface, but it takes ages to get the SS hot. The result is that the solder won't stick to the SS. Discovered there's a BOC not far from home, so Monday I will go to BOC and buy some better flux and maybe some rods to play around with.

Originally Posted by isuzutoo-eh

Stainless has lower thermal conductivity than brass, this means that if the size of the materials is equal the SS will keep the heat localised and have less heat sinking. But you have a tiny pimple of brass on a big lump of SS, so you'll need to heat the SS for longer to get it to the same temperature.
You can add the flux after the metal is up to temperature too, using a wooden spatula or a screwdriver (just don't solder it on!), but be careful as it may spit and spatter into your eyes or onto your skin.

I tried the screwdriver trick, but the flux didn't get much of a chance to do anything before being rapidly spat everywhere!

Originally Posted by slug_burner

If you have a gas bbq burner put your ss pipe onto that for extra heat. My dad would silver solder on the kitchen cook top to help his soldering iron along.

WIth my level of skill presently, I think it's best I keep the flux and solder away from the stove top!! I plan to get my rental bond back when I move out!

Went to BOC and purchased some of these.



BOC man said it's impossible to braze or solder stainless without an oxy. I also purchased a MAP gas blow torch - which he also said wouldn't be hot enough.

Then I did this first go with MAP gas and the 45% silver solder rods.

Still hot:



Cooled down and wire brushed only:



Good enough for me!