I have spent a lot of time investigating this, since I have been
living in small rentals, and other people's homes. There is a
surprising amount one can accomplish with a good butane torch. For
safety's sake (as well as for more flame adjustability), buy a high
quality one, with as many metal parts as possible, so that it won't
melt in your hand. Most people recommend a Blazer:
This solution isn't very economical, and you will be refilling the
torch quite often, but it is about as safe using your stove. These
torches are sold, for making cr=eme brulee, in kitchen supply stores
(usually the cheapest places to purchase quality refills), and I find
it hard to imagine that your condo association would object to them.
They're great for fusing fine silver wire.
As for the small, "disposable" propane tanks, they are used
regularly, by plumbers, in small, tight, indoor places, and I suspect
they are equally safe (and legal) to use in your condo. Because I
have much less torch experience than you do, I felt safer with the
butane, but I suspect this is a purely emotional reaction. The
advantage of the small propane torch is that you can get a kit for it
with different size tips-see here:
Katherine Palochak told me she uses small propane torches when she
gives out-of-town workshops and is able to get them to do just about
anything she needs them to do.
Albion, CA, US