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So I was bending a lucite stem over my heat gun and let it sit just a little too long. It melted a little and bubbled. I sanded it down a bit but the bubbles are still there. If I am more aggressive can I get through them or is the material already toast? What's the trick for not melting the stem in the future? Further from the heat source? Lower gun setting? Combination of both?

Joel

It's likely "toast," but it really just depends on how hot you got it and how much of the material turned molten.

While it sounds counterintuitive, I think you get much greater control by using an alcohol burner and passing the stem directly through the flame. In the same manner that you can pass your finger through a flame once or twice without burning it, the same can be done with a rubber or acrylic stem. The difference is that the source of heat is more concentrated and can be directed into or away from specific areas--like edges or very thin spots. For this procedure, you literally pass the stem quickly back and forth through the flame making sure that with each pass, the stem travels beyond the edges of the flame. This can also be done with something as simple as a candle, but it will create soot since you're actually burning the wick and carbon is being released. Give it a try and see how it goes.

Todd

If you use a heat gun:
- keep the stem about 4 to 6 inches from the nozzle
- keep it moving and turning
- watch the stem like a hawk
- make little test bends to see when it's pliable enough

You can get decent control with a heat gun, but it's easy to mess it up, like you found. The most important thing is to keep the stem moving - never let it rest in one place, ever.

I definitely held it to close to the gun then. I was about two inches and not moving much. Good to know. I may try the other method some time as well. Thanks.

Interesting! Naked flame or heatgun? Which one is preferred?

That depends on the maker. I tried Todd's method once, and it didn't work out for me. I also tried boiling water, but that changed the tenon diameter. I tried a toaster oven, but the results of that were spectacular failure - burned stems and a really pissed off wife. I have not tried a sandbox, but I can see how it would work well. All of the above are used by one maker or another with good results.

It boils down to using methods, tools, and materials that you're comfortable with.

I use a heat gun.

As long as you keep it moving, it works great.

I've never tried an alcohol flame, but I have used Tinky's sand box. It works fine but you have to make sure all of the little grains of glass bead are off the stem before bending, or you can leave a bunch of tiny indentations on the surface, which can be removed with more heat.

Wash, rinse, repeat.

Rad

RadDavis wrote:.... but I have used Tinky's sand box.

I also tried that, but Tinky was using the sandbox at the time. Man, was she one pissed off cat.
Seriously, I do have a cat named Tinker.

The heat gun works well for me...tho I have used an oven on a bed of salt as well as boiling water for some limited bending work.
With the heat gun, one has hands on control of the process.
I've not tried the candle or alcohol burner up til this time.

As has been said, keep rotating the stem and moving it..no closer than 6" to the gun's nozzle.
I place a thin solid brass wire ( just less diameter than the smoke passage) thru the stem smoke passage and hold the stem on each end with a small dampened cloth.

I feel the stem periodically( every ten to twenty seconds) to see it's heat and gently test how pliable it is.Bare fingers.

Your fingers can stand to touch pretty hot things MOMENTARILY ..so you can get a feel for how warm and pliable the stem is getting.

There is no set time as stem materials and thicknesses and contours vary.
You must get the material heated through to the center on all sides for a good even bend.
I bend some by eye and hand and others I use a bending radius template to help..as simple as a small glass bottle laying on a potholder..

Once you get the stem bent to the shape desired, keep the bending tension on it firmly until it cools a bit and then while maintaining the bend by hand, dunk the stem in cool water to set and cool the stem.
IF you are bending a stem that MUST fit a fine hard pipe case like the old meerschaums have, you may find that bending a tad beyond required will work well..Most material has some mempory and even tho bent, the stem will come back a bit as it cools and your perfect bend may not be quite right.


Sometimes I have bent stems in two or three operations and looked in between..
Bending stems with ring and grooves/ball can be tricky if you don't heat evenly, ESP if any of your bend is in the ring/groove/ball area.
The ball heats thru slower than the thin grooved section so slow even heating is the ticket there for sure.

Bending by degrees works for the most precise bends but each time you resume bending the stem will need to be brought back up to bending temperature again.

In my experience, high heat is not required..200-240F is sufficient...often less.
Important that the stem be heated evenly all the way thru and from all sides where you want to bend it and a bit on either side.

IF you have the opportunity to buy broken pipes, even an oxidized or badly bitten stem good for nothing is good practice material.Such pipes can be had for far less than the price of a new vulcanite or lucite stem and you may have a pipe or ferrule or other part that can be put to use down the road and give good smoking service again.
Pipe making, if nothing else, is a good way to learn patience and planning.. and it is much more than just that for most of us..Jim

I use a variable setting heat gun with good results. Me and open flame is, generally, a bad idea. Especially when other flamables are close by. I've only had one minor failure early on with a heat gun where I got it too hot and discolored the stem. I use the method Kurt described above. You've gotta keep it rotating and moving and test bend often to see where you're at and what areas need more attention.

One thing to be aware of with heat... If you have a (delrin) tenon epoxied into the stem, you run the risk of losing that epoxy bond with too much heat. Even if you're not heating all the way to the shank, the stem material is a heat sink and the entire stem heats up.