Brazing Gas Question

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I have searched the web but can't seem to find a good answer to this....todays "MAPP" gas ("MAP-Pro" for example) is about 7x as expensive as propane from what I can determine (I compared the cost of the 14.1 oz bottles of MAP-Pro to what I can fill my 20# propane tanks (15# actual) for). For brazing copper it would seem that while MAP-Pro would be faster than propane, for everyday hobbiest work propane would make more sense given the cost difference. Again- this is not in a fab shop where the time difference cost of labor may offset the difference in fuel cost. Has anyone done this comparison? Am I missing anything?
Reply:The MAPP gas burns hotter and as a result gets the work done a LOT faster. A few years ago I bought a Bernzomatic that came with a two pack of cylinders from HD. I'm on my third cylinder and I use it a few times a week. Before I switched to the MAPP gas I burned through a propane cylinder in a couple weeks. It's like the cylinder is bottomless.I did some tests brazing with my Bernzomatic that finally used up a cylinder but I was burning like 10 minutes to get it hot enough. You really need an oxygen to get the heat required to braze but I'm sure you know that. http://weldingweb.com/vbb/showthread.php?t=129421
Reply:Thanks forhire....so you found in your nut and bolt example that the heat loss was so great to make "pure/just" MAP a problem in trying to braze that. I had not considered the heat loss aspect of the material being brazed- thanks very much!  I really appreciate it. It makes sense. If the material was much thinner (copper tube etc.) it would seem that my propane example would work, no?
Reply:Originally Posted by WilbahIf the material was much thinner (copper tube etc.) it would seem that my propane example would work, no?
Reply:We use acetylene when brazing copper, espeically when it comes to refrigeration lines. If the lines that we are brazing are bigger then an 1.5", then I grab the Oxygen bottle to speed things up.. One has to be careful when using Oxygen with Acetylene that you don't put a hole through the material you are trying to braze.. Seen that happen many of times .. I never used propane to braze anything, so i can't really help you on the cost difference.
Reply:Originally Posted by WilbahIf the material was much thinner (copper tube etc.) it would seem that my propane example would work, no?
Reply:Originally Posted by WilbahI have searched the web but can't seem to find a good answer to this....todays "MAPP" gas ("MAP-Pro" for example) is about 7x as expensive as propane from what I can determine (I compared the cost of the 14.1 oz bottles of MAP-Pro to what I can fill my 20# propane tanks (15# actual) for). Am I missing anything?
Reply:Originally Posted by KelvinI once needed to replace a zone valve in the copper tubing in my home heating system. I used a propane-air torch to try to solder the joint, and it took a LONG time to get the joint hot enough to melt the solder. After I finally got it soldered up, I discovered that the zone valve got ruined because it got too hot.