Before I turn some pretty celluloid into a pool of molten plastic, can I get some basic instructions on the proper use of a heat gun to loosen a section? Thanks.

Carefully!!

Seriously though, the best way to figure this out is through trialing with a thermometer. I use a small heat gun used for embossing in scrapbooking, it is the same one that Giovanni sells at Tryphon.it and has worked for me for a couple of years. Use a thermometer and hold it in the hot air stream at about 2" from the nozzle and see what the temperature reads. You want about 160deg F if I recall correctly. Move the thermometer away from the heat gun until you figure out where you get this level of heat and no more. That is as close as you want to hold a pen barrel.

Heat the barrel until you can safely hold it when heated for a couple of seconds without burning yourself. If it is too hot, then do nothing on the pen until it cools a bit. Pens will not burst into flames immediately, but the phase change from hot to smouldering to on fire is exceedingly quick. The margin for error is this thin >< when you get it too hot. It will usually take about 30 seconds or so for the pen to become too hot, but this depends on the condition of the celluloid. If it is breaking down already, then it will take much less heat to flambe the pen. The time it takes for the pen to burn also depends on how close you have the pen to the heat source.

Ensure that the pen is always rotating when in the air stream, holding it still will build up heat quickly in one area.

Be very vigilant while heating pens, do not have any other distractions. Any time that I have flambe'd a pen I was not watching closely or paying enough attention to what I was doing.

Disclaimer time: Celluloid burns VERY VERY rapidly, nearly explosively. Always have a glass of water or a bowl to extinguish flames FAST. I once burned a section of a Vacumatic and in the second it took to figure out that it was smoking (not even on fire yet) it burst into flames before I could move my hand 12" to drop it in water. 3/4 of the section dissapeared in that time and was replaced by mounds of ash and pillars of smoke.

Hot celluloid will burn you easily if you are not careful. My fingers are used to the heat and I can take more than most people could, which is not so good really. I have less sense of when the pen is too hot now, so I always work up to the correct temperature. Heat and check, heat and check, always rotating the heated material.

I did remove teeth marks from a Vac blind cap once that were nearly half the way through the material. The whole blind cap was warmed to the point that if I held it anywhere other than vertical it would start to flow due to it being so soft. I was REALLY LUCKY. Also, remember that edges build up heat WAY quicker than sides of a pen, do not heat caplips or edges of barrels very much. Caplips can basically explode into cracked remainders of a cap in no time.

Patience, vigilence and practice are the keys. Try it out on a junker, and keep the windos open, as well as water at your side where it will not be knocked over in your haste to extinguish a burning pen. Once you have seen celluloid burn you will understand why experts are a bit cagey about this.

Ron Z and I have discussed at length putting up a video of celluloid burning to show how dangerous it can be. I think that it is time I actually did make this video.

Cheers,
Sean

Wow, that's why I use a regular hair dryer and warm water.

I've jury rigged a hot plate, pot & dimmer switch into a small oven for the purpose of removing dents & teethmarks. It allows for a more precise temperature for an extended period of time.

I use a small electric oven (inside wich I "cook" flute and clarinet pads when repadding and cure epoxi when repairing crack in clarinet joints) works like a charm.

I have a milwaukee heat gun that I originally bought to remove putty from old windows. It is adjustable and shows a digital output of the heat. It works great for pens since I can adjust the heat output. Having said that, the best temperature guage is your fingers. If it's too hot to hold, its probably too hot for what you are trying to do. These guns are expensive, but I got mine at a house sale for $20. I love how the bite marks on a parker vacumatic pop out with the corrrect amount of heat. That is of course, right before it bursts into flame!
Cheers,
Rob

I paid nearly $160 for a Steinel heat gun with heat control in 10 degree steps, digital readout etc. It sits in my bench most of the time. I prefer to use the small embossing heat guns sold at A. C. Moore. They're smaller, hang on the edge of the bench, and as Sean described, you get a range of heat by varying the distance from the outlet. The outlet is about 1/2" in diameter, so the heat source is more focused than a standard heat gun, which is also a good thing.

And if you have a coupon you can get one for about $9.99.

I use a Craftsman Industrial model that's infinitely adjustable - with a low temp point of around 100 degrees F. I purchased this after some bad experiences with guns that ran way too hot for pen work. The Craftsman isn't cheap - I think I paid around $100 for it, but it sets upright on the bench, has a small nozzle to aid in heating only what's needed, and can be accurately adjusted to any temp. needed. It's also handy for lots of other uses - I was repairing my lawn sprinkler system yesterday and used the gun to heat some poly-pipe to aid in inserting a barbed fitting - worked like a charm - maybe I should have shellacked it in place?

I highly recommend Sean's advice of using a thermometer to check your heat level - it's very disappointing to destroy an otherwise good pen because of over-heating.