Re-Bending a Bent Stem

[AroEnglish]

I’ve got a pipe with a bent stem that wasn't bent to my liking. The bend was slightly more abrupt rather than being gradual. Is it possible to change the bend of a stem after it's been set?

Below are some pictures to give you an idea of what I’m talking about. The first picture is an example of a stem that has a more abrupt bend (though not so bad, in this case). The second photo is an example of a stem with a gradual bend.





A more extreme example of an abruptly bent stem are the one that come from MM. This is just a visual example as I believe MM molds the stems in this shape rather than bending a straight stem.

 

[Chasing Embers]

Is it possible to change the bend of a stem after it's been set?

Yep.

Insert a pipe cleaner into the stem and slowly heat it with a heat gun. The stem will begin to straighten as it becomes soft. Bend it to the desired shape and run cold water over it to set it.

 

[georged]

Getting a smooth bend on a tapered stem is far more difficult than most people would guess. Saddle stems (blades) are pretty straightforward, but tapered ones not so much.

Length and diameter are both difficulty multipliers (shorter & thicker = more ass-kicky)

Definitely work with leather gloves, shield/mask the base of the stem to protect the tenon from heat as much as possible, do NOT be tempted to set the heatgun to high to speed things up, and don't be afraid to bend in stages or segments to achieve the desired shape.

It's possible that the surface of the stem will show some texture after being bent and cooled, from pressure and stretching/compression. If so, "flash" it close to the gun nozzle to soften the surface and let it relax before trying to sand such texture out.

I can pretty much guarantee you won't be happy with the result after your first attempt. No worries, though, just do it again, repeating as many times as it takes to be happy with it. Often you'll talk yourself into being happy to be finished with the work, but it'll bother you the next day, or a week or a month later. If so, just repeat the exercise. Each time you'll get a better feel for pressure, soak time, etc.

Oh yeah... I do NOT recommend holding the pipe in one hand and the gun in the other for all kinds of reasons (too many to list). Mount the gun in a way that lets you use both hands on the pipe.

Finally, an inserted pipe cleaner, besides cotton fuzz having no strength, is one of those "never dies" myth things. 100% unnecessary. The geometry of the situation doesn't require airway support. It will not close or "pinch".

 

[AroEnglish]

Getting a smooth bend on a tapered stem is far more difficult than most people would guess. Saddle stems (blades) are pretty straightforward, but tapered ones not so much.

Length and diameter are both difficulty multipliers (shorter & thicker = more ass-kicky)

Definitely work with leather gloves, shield/mask the base of the stem to protect the tenon from heat as much as possible, do NOT be tempted to set the heatgun to high to speed things up, and don't be afraid to bend in stages or segments to achieve the desired shape.

It's possible that the surface of the stem will show some texture after being bent and cooled, from pressure and stretching/compression. If so, "flash" it close to the gun nozzle to soften the surface and let it relax before trying to sand such texture out.

I can pretty much guarantee you won't be happy with the result after your first attempt. No worries, though, just do it again, repeating as many times as it takes to be happy with it. Often you'll talk yourself into being happy to be finished with the work, but it'll bother you the next day, or a week or a month later. If so, just repeat the exercise. Each time you'll get a better feel for pressure, soak time, etc.

Oh yeah... I do NOT recommend holding the pipe in one hand and the gun in the other for all kinds of reasons (too many to list). Mount the gun in a way that lets you use both hands on the pipe.

Finally, an inserted pipe cleaner, besides cotton fuzz having no strength, is one of those "never dies" myth things. 100% unnecessary. The geometry of the situation doesn't require airway support. It will not close or "pinch".

Thanks for the thorough explanation!

Are there things I should watch out for if I'm bending a vulcanite stem versus an acrylic stem?

 

[Chasing Embers]

Thanks for the thorough explanation!

Are there things I should watch out for if I'm bending a vulcanite stem versus an acrylic stem?

Vulcanite softens more quickly and bubbles can develop in acrylic. Above all, heat slowly.

 

[sleepy57]

I think those MM pipe stems are Plastic not Vulcanite

 

[bassbug]

You might want to try boiling water rather than a heat gun. it will take longer but the risk of burning the stem is all but eliminated.