No one has mentioned it, but I've had good luck with heating sections over a bare 40 or 60 Watt light bulb.
It just hard to see afterwards. *blink* *blink*
Well, looks like Mike set the stage for a little confession time here.
(Thanks alot Mike!
I was in the past a big proponent of this idea. (In fact, months ago, I DID post a post about it when I first thought it was a newly discovered <for me> GREAT idea!) I've learned since that you need to be careful with it.
The good news is (IMO) the heat application is nice and even and slow which on the surface sounds good. The not so good part
(IMO) turns out to be the "slow" part.
If one is not careful, the heat from those bulbs can migrate down the barrel and possibly get it warm enough for not good
things to happen like barrel bulge (where the lever retaining ring presses the softened celluloid outwards creating a ring like bulge) or even warping the barrel. (damhIk, Ijk, ok?) Now, I have found a way to mitigate the odds of that happening and that's to make kind of a wrapped paper toweling insulation blanket around the part of the barrel I DON'T want to get warm and that does help (while I'm there, I also fashion a mini-blanket to go over the section so that the only part directly exposed to the heat is the about 3/4" of the end of the barrel I really want to soften/expand). Honestly, all this extra safeguarding tended to negate the "lazy man's way" of section seperation that I thought this would be to start with. (And, while the insulating "blanket" DOES stop the direct radiating heat, it DOESN'T affect the heat simply migrating down the barrel itself...)
These days, I am much more in favor of sufficiently hot enough heat, focused and applied directly to just the area in question for as little time as possible to accomplish the mission. I think this is the safest method for the surrounding areas of the barrel that don't take so kindly to heat.
Bruce in Ocala, FL