On 14/11/2012 22:07, Chris Bartram wrote:
On 14/11/12 13:42, Adam Funk wrote:
I'm trying to curl up some small copper pipe (or tube, if you prefer)
to make a toy boat along this line:

https://en.wikipedia.org/wiki/File:R...pe_pop_pop.JPG

I tried some 10 mm (or so) pipe that I found in the cellar, and it
kinked too easily. I got some "5 mm X 0.45 mm" tubes from a hobby
shop (aimed at model railways, I think), and that's even harder to
bend & easier to kink.

Is it worth trying to anneal a piece with a blowtorch? If so, what's
the best procedure?

Try copper brake pipe.

Normal brake pipe is plated steel, top quality brake pipe is a copper
nickel alloy of some sort. Both of these have lower thermal conductivity
than copper, and will be significantly thicker than you need for your
working pressures.