On Nov 14, 1:45*pm, 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?

Most of the copper pipe you buy is in hard or "half hard " condition.
Makes it stronger.
You can anneal it by heating to red heat and letting cool.
It will then bend better but will have reduced pressure rating.

Annealed pipe can be bought, it usually comes in a coil and is thicker
guage hence more expensive.

One thing you might do if it is a project is consider automotive
hydraulic copper brake pipe if you need a really high pressure.