MAPP gas burns hotter. I use it for soldering all the time. It works faster and seems cleaner to me. No real difference in technique except it takes less time to heat the joint. The MAPP (methylacetylene-propadiene 44% and propane 56%) sold in small cylinders contains a substantial percentage of propane. The above ratio is from Bernz-O-Matic. MSDS here:

http://www.bernzomatic.com/bernzomatic/consumer/resources/MSDSMapp.pdf

Timbear - hi, TomH is right - MAPP burns hotter. I was trying to repair a hose bibb at my mother-in-law's house before and was using regular propane to heat the connection (copper pipe to hose bibb end). Propane wouldn't quite get things hot enough to allow the solder to melt/seal properly (the capillary action never happened). A neighbor who was a retired plumber told her I needed to use MAPP gas. I got some and voila! - the joint was fixed in under a minute.

I've used regular propane before when dealing with copper-to-copper connections. However, since the hose bibb thing (2 years ago) I only use MAPP gas for my plumbing repairs...it's faster because it burns hotter. One caution I've read elsewhere is you need to use a soldering/brazing torch tip made for MAPP gas if you need to burn the torch for extended periods - otherwise, a standard propane tip may begin to melt. I haven't experienced it myself - I just read the caution elsewhere.

I hope this helps some - regards! Jim D/West Point, VA

Tom and Jim,

Thanks so much! That will save me some trouble I am sure!