Tips on bending Alluminium a/c tube?

[Z2TT]

Hello,

I need to bend an aircon tube for a conversion I'm doing. Does anybody have any tips for bending aluminum tubes with getting minimum kinks/distortion? ID is about 15mm wall thickness about 1.5-2mm

Thanks.

[gmonkey]

use pipe overlay benders.. they look like a compressed spring and about 20cm or so long. Heat the pipe with an oxy/acetalene and then place the bender over the top and slowly bend working way around, dont bend in one spot

or a pipe bender made for the correct size of pipe.. heat always helps

[gmonkey]

oh yeh dont over heat to the point you make a hole..aircon gas is highly flamable your best to evac the system first but obviously that costs. so be careful

[spectral]

is the system currently gased? If not, take off the pipe, fill it tightly with sand, seal it off then bend it with heat. The sand supports the pipe wall and helps stop kinks and collapse.

[eeeyan]

Is it de-gassed? If it is stop being cheap remove it, take it to a pipe bender and ask for 1 bend they'll do it for a tenner most likely.

[Z2TT]

The pipes will be off the car and the system won't be gassed.

[MWP]

A trick i saw somewhere for annealing aluminum for bending....
Smear some dish washing liquid on the ally. Heat gently with a torch until the liquid turns white.

Havent tried it myself though...

[edit]
I remember... they showed it being done in the British series "A 4x4 Is Born".
Quite a good series to watch.

[gmonkey]

a good way to move ali without damaging the surface it is use an oxy/ace with oxygen pretty much one click from off so its black soot, cover the surface with the soot then turn the oxygen on and then heat the surface over the soot. wipe down after. Keeps all flush and shiney

[william]

oh yeh dont over heat to the point you make a hole..aircon gas is highly flamable your best to evac the system first but obviously that costs. so be careful

R134a is non flamable

[mick08]

R134a isn't flammable but the oil mixed with will be so there could be flames if you put a torch near an open A/C line, not that this bloke will do that caus he is going to remove the pipe for bending.

[Z2TT]

Yeah well since I need to bend the pipes in order to make them fit, there is no way they can be connected to the engine pre-bending, as they wouldn't fit

Anyway thanks for the tips guys keep them coming, could I use a Mapp gas torch instead of oxy?

[allencr]

V-belt pully/sheve to bend against for the radius you need, and ball bearings or ice inside as the mandrel to keep it from kinking.

[litldv8]

a good way to move ali without damaging the surface it is use an oxy/ace with oxygen pretty much one click from off so its black soot, cover the surface with the soot then turn the oxygen on and then heat the surface over the soot. wipe down after. Keeps all flush and shiney

i have used this method to fix bent ally trays and works very well
neil