Bending thin walled tube

[mikemill]

Watching a program on making musical instruments to aid bending thin walled brass tubing cap one end fill with water and freeze then bend, ice keeps the tube from distorting, easy.
Mike

[Allen Smithee]

Yes, but remember to anneal the tube *before* filling it with ice...

 

AS

[mklotz]

The annealing is not just recommended; it's essential.

After annealing, I've bent small diameter tubing successfully with this tool...

http://www.harborfreight.com/1-8-eighth-inch-to-1-4-quarter-inch-tube-bender-94571.html

without any ice or Woods metal filling.  Give it a try; it's an inexpensive experiment.

[Hugh Currin]

I'd have thought freezing water inside a tube would expand it. It might split but would certainly be larger diameter than original. Or is there something I'm missing?

I remember re-plumbing a trailer with copper lines. Some split and some just got bigger. Took a piece of expanded tubing to the store and tried to buy fittings for them, no joy.

Watching a program on making musical instruments to aid bending thin walled brass tubing cap one end fill with water and freeze then bend, ice keeps the tube from distorting, easy.
Mike

Thanks.

Hugh

[mikemill]

As always there is more then one way to skin a cat and we all have our proven ways of  doing things, I think the trick is leaving one end of the tube open alows the freezing water to expand and not damage the tube.
I have not tried this process just quoting what I watched on the program, seemed a good idea to me!!!

Mike

[Stuart]

I have used lead

note not solder or any flux

just plain old lead melt it and fill the tube with no flux it will melt out again clean

but do not try it with 1/16 od tube it will nor go down the hole

as has been said anneal the tube

Stuart

[Dave Sohlstrom]

I need to bend some 1/4" thin wall copper tube. As a test I annealed then crimped and soldered one end. Next I filled the tube with very fine sand and crimped and soldered other end. bent to a 3/4" radius no problem. cut off ends and remove sand.

Dave

[mcostello]

I have seen the OP's program on "How it's made." I believe they mentioned putting soap in the water so it was not as hard. Another program mentioned using pitch.

[wot]

I've seen it done with free flowing table salt instead of sand, the salt is then dissolved by dripping water into the tube until the water flows through the tube and out of the other end.