Acetylene VS MAPP

The primary motive for MAPP gas was that it is much safer than acetylene. there is no 15 psi limit and is permissible to use on board ship and in mines. It puts out more temperature than propane but if you are doing any serious welding and brazing it will not be comparable to acetylene. I have actually welded with it and yes it can be done but the heat/flame is not concentrated enough and it is not practical. You also can braze with it but again the heat is very spread out. It is primarily a cutting gas. If you intend to save money by changing over to an alternative to acetylene then change over to propane and be done with it. You cannot weld or braze decently with propane. Propane is an excellent gas for cutting. It takes longer to preheat before actually starting the cut but the cut is cleaner with less slag and the height of the tip while cutting is not as critical. For cutting with fuel gasses you need the two piece cutting tips. It takes a knack to lighting but that is easily overcome. Randy
In my travels a year or so ago I was able to get a good size bottle of MAPP and a small O2 cylinder, it came with one of those MINI torches, its been sitting since. Whats to using my Oxy/Acetylene torches with the MAPP gas?? I sure would like to make use of the gas, how is it compared to the Acetylene in cutting, welding, brazing? Any help would be great.
I will post this over in the welding group too.

I don't have plans to change over to MAPP, but would like to use the cylinder I have unless it means all new tips. I like the idea of using propane to cut, its cheaper and I can get it in town, I assume I need a proper regulator and tips to use propane.

All the "LP" gasses can be used with an acetylene regulator.
Propane, Propylene, Propadiene, Methane (city gas), MAPP (Methyl-Acetylene Poly-Proylene), Flamal, Chemtane. They all work with acetylene regulators. You should use T hoses with all LP gasses, R hoses are for acetylene only. The R hoses will work on LP gasses, but the exposure to LP gas will shorten their life-span.
All the LP gasses are better for cutting than Acetylene, with a cleaner edge, top and bottom, and less heat distortion.
LP gasses will work fine with existing torches, but you will need the LP style cutting tips. One more thing LP gasses do better than acetylene, is that they can really make BIG rosebud tips scream. With acetylene you are limited as to how much gas you can draw at one time, so BIG rosebud tips will tend to fade out and pop a lot. With LP gasses a Victor #15 rosebud can make a HUGE flame and sustain it with no difficulty.
I finally got rid of my big shop acetylene tank. I still have some tiny ones for jewelry work, but I have been working my way through a bottle of Flamal for the last 4 years. At the Divers Institute I am using Chemtane and at South Seattle Comm. Coll. we use Propylene.
MAPP, Flamal, and Chemtane are LP gas mixes designed to develop more heat than Propane, but with the same dense liquid storage. They cost more, but are quite a bit hotter than propane. A bottle of LP gas should last at least 4 times as long as a similarly sized bottle of acetylene.
From what I have heard, MAPP is going away, because one of the constituant gasses, Propadiene, is more valuable to the plastics industry than it is to the welding industry.
My favorite MAPP replacement so far is Chemtane.
Many of the commercial burning shops in Seattle have also switched over to Chemtane.

Might depend on what you do. I've switched from O/A to air-propane. Propane is a lower temperature gas so, I've also switched to using filler alloys that have a lower melt temperature. Instead of using brass/bronze, I'm now using silver alloys, mostly AWS BAg-34, using a propane powered Turbo-Torch as a heat source. One thing I've found is that if you want good results, you must always use Black Flux, no exceptions . You have a bigger HAZ (heat affected zone) with propane but, for what I do, it doesn't matter.
Switching to air-propane simplified my life considerably in not having to deal with a distant gas supplier who likes to keep 9-5 office hours, is closed on weekends, and doesn't deliver, not to mention the cost of tank rentals. Now, I get my propane at the corner service station and run the Turbo-Torches off 40 lb tanks I purchased at the local RV shop.
Costwise, it is probably a wash. The silver alloy filler is more expensive but, an air-propane torch is a lot less expensive to operate than an O/A torch. For me, the payoff is in the convenience in not having to deal with an ornery gas supplier 100 miles away.
I only have one O/A torch now. The only thing I use it for these days is for cutting, and don't do much of that. Haven't refilled the tanks in over 2 years.

Does your O2 consumption go up significantly with Propane/Oxygen? I have read that propane requires twice the O2.
Bob