MAPP gas vs Propane?

[awp101]

bsims's comments on heating his CETME MB with propane got me to wondering.

What's the difference between MAPP gas and propane?

I know most 'smiths use silver solder to attach the MB's because it has a higher melting temp than the BATFE regs require (1400 degrees is the minimum IIRC) and I sem to recall most of them saying they use MAPP gas.

If propane doesn't get as hot as MAPP, could that be the reason bsims's MB won't budge?

[bsims]

Correct, MAPP burns alot hotter than propane. You might get high temp silver solder to flow with a propane torch, but it would take awhile. However, Century had never silver soldered their brakes on in the past, and I'm not sure why they'd both silver solder and blind pin it. Heat it often used to loosen things up a bit - the expansion and contraction will often cause parts that are "frozen" together to loosen. That's really what I was trying to accomplish with the propane torch, although based on the result, they may have SS'ed it on as well - who knows.

Brian

[SalBO]

MAPP gas is hotter as Bsims said.......the silver solder temp required is 1100 F. MAPP is also about 4 times the price too.
I got lucky that one I bought a couple years ago uses both and not just propane.