Brazing copper

[Tractor Seabee]

From and old pipefitter; certified sil brazer: Good info above but some not so good. If all your joints are copper to copper you can use what is called Phos Copper or Sil-phos. Both do not need flux on copper to copper. For 1/2 copper tube and fittings you should be ok with a prestolite air-acetylene torch, air/propane may be iffy. I have done up to 1 1/8" OD that way. Mapp gas and O/A are OK but easy to overheat. The joints are heated till the brazing metal sucks up onto the joint like soft solder does. Copper to steel or brass/bronze requires at least 15% silver alloy and flux. For all brazing the materials need to be bright and shiney. As pipes get larger mapp gas, propane/ox, or O/A are needed to get enough heat.

Terminology: Brazing is a lower temp process and the joints are filled by capillary attraction whereas Bronze Welding only deposists on the surface like other welding except it does not fuse with the base material.

 

[ray66v]

You guys know they stopped making MAPP gas in 2008?

All the stuff they sell today is fake. It's just hopped up propane.

I thought I was imagining things, when I noticed it was not heating as fast as it used to.

 

[meos1]

From and old pipefitter; certified sil brazer: Good info above but some not so good. If all your joints are copper to copper you can use what is called Phos Copper or Sil-phos. Both do not need flux on copper to copper. For 1/2 copper tube and fittings you should be ok with a prestolite air-acetylene torch, air/propane may be iffy. I have done up to 1 1/8" OD that way. Mapp gas and O/A are OK but easy to overheat. The joints are heated till the brazing metal sucks up onto the joint like soft solder does. Copper to steel or brass/bronze requires at least 15% silver alloy and flux. For all brazing the materials need to be bright and shiney. As pipes get larger mapp gas, propane/ox, or O/A are needed to get enough heat.

Terminology: Brazing is a lower temp process and the joints are filled by capillary attraction whereas Bronze Welding only deposists on the surface like other welding except it does not fuse with the base material.

Marked as answer - He is right on the money.