I was thinking of Smith Little Torch (MAPP/oxygen) and using it
with disposable canisters
Sam, Aside from 'personal working preference' the issue of the tanks
themselves comes down to safety and cost. You certainly don't want
to keep 20 lb propane tanks indoors, regardless of what some seem to
think, it is just plain foolhardy and illegal. You've researched it I
assume so I won't go into the specifics. There is no similar
restriction that I have heard of regarding larger oxy cylinders. But
check you local fire code.
Using the 1 lb oxy bottles will get costly over time for sure.
Here's a nice compromise that my fire marshall is satisfied with... I
have a #80 oxy tank (about 3 1/2 feet tall) which costs about $20 to
fill and lasts me several months. For fuel I use disposable propane
bottles meant for camping equipment, cost about $1.88. The same size
bernzamatic bottles are about $10. The Colemans are low and stable
the Bernz are tall and 'tippy'.
I've never used mapp but if you like it because its hot with air,
you might find propane/oxy hot enough for your working habits.
Any torch with two lines will require either oxy or compressed air.
For ambient air you need a torch designed with a mixer in the head.
So if you want to use the little torch with mapp/air you will need a
compressor of some sort. Balance the step-into cost of that with the
oxy step-into cost, which is basically compressor cost vs oxy tank
purchase or lease and regulator. Compressed air would be safer than
an oxy bottle.
The silversmith I employed used a propane/air torch for most of his
work, which included soldering hollow candlabra bases where the
silver is only about .012" thick. The compressor was noisy but not
overly obnoxious. For heavy pieces he used a propane/oxy torch.
I have seen single hose torches that fit 1lb bottles but I have no
experience with it. Ceratainly an inexpensive option. But I doubt
you'd get the heat control you seek although it would be more
I hope you find some of that useful.