I have and idea and thought I would ask the "all knowing" frame builders what they though.

I have a small but noticeable dent in my toptube from a garage door coming down on it. My thought is to heat that area of the frame with a heatgun and then cool it quickly with dry ice. I know this works with thinner metal like car door panels and what not. What about thicker metal like an aluminum frame?

Discuss!

Anyone? Hello?

Is this thing ON? *tap tap

Will this work?

1) Yes

2) No

3) I don't know

4) Pwnt, you're damned idiot!

Please circle what you feel to be the correct answer.

all of the above?

:sadface:

seriously, though, you should try it and let folks know.
is your frame lugged? if it is, you can always replace the top tube if you REALLY mess it up,
but how likely is that?

Not lugged. I personally think it will work. Can't think of a reason it would'nt. But I'm not the brightest crayon in the box so I was looking for a second opinion.

You are likely to do something nasty to the hardness of the aluminum, not knowing what alloy it is, I can't say. Just use some 5 minute epoxy to fill the dent, or a proper filler, and drive on.

oh, its aluminum?
hmmm.... what are car doors made out of?

Aluminum conducts heat too well for the torch/ice to only affect one small area. I doubt this would work on steel tube either. A tube just seems too rigid of a structure. 18g sheet is fairly flimsy which is why the ice trick works on large panels. There can't be any harm in trying, though. How hot does your heatgun get? I don't think you'll harm the Al if you keep it under 300F.

I'm gonna give it a 'go' sometime this week and I'll let ya know. Just gotta find some dryice.

Get a can of Air - hold upside down when you spray and CO2 liquid comes out - very cold.

I don't think it will work either but it never hurts to try.

The old steel frame dent removal trick might work on your Al frame as well...

Get a block of hardwood, like oak, and drill a hole in it the same size as your frame tube. Cut the wood in half so there are channels in each piece. Clamp the blocks with the channels over the dented area. (assuming there are no cable guides in the way) As you slowly tighten the vice, twist the frame so that the dented tube is moving back & forth in the hole. Keep tightening and twisting. Eventually, most of the dent will be pushed back out. The rest you can fill with a little Bondo.

Just an idea. Good luck with that!

I'm thinking that it would soften the tubing. If I want to heattreat or harden the alum. tubing, I would heat it up and then cool very slowly.

Well, it didn't work. I went with the just using dry ice method but the only thing it did was make my hands really cold. I guess I will just have to live with it. Thanks everyone for your input.

What you could've done was use epoxy to fill in the dent, with a small piece of metal or fiberglass over that to keep the strength of the top bar intact.

Heat treatment is very tricky, especially in a homemade setting.

Want special alloys? Get a large drill, and fill *over* the circular gap with a bent coin & epoxy.