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bending tube
pre lit - 29/7/10 at 11:21 AM

i am bending the front hoop for my cage from 38mm cds the two bends are approx 730 mm apart the first bend is ok but the second one one kinks is there anything i can do to stop this happening as its going to get expensive the tube is being bent cold with nothing inside would sand help to stop it kinking it is being bent with a decent hydraulic pipe bender
thanks

Alan B - 29/7/10 at 11:37 AM

I doesn't matter how decent your pipe bender is....it's still a pipe bender...designed for the relatively thick walls of piping.

You need a tube bender which works on a different principle...it draws it around a former rather than vee bending it.

Even a tube bender will struggle if the wall gets too thin...then you need a mandrel type tube bender.

Minicooper - 29/7/10 at 11:45 AM

Where are you based prelit if your anywhere near Chandlers Ford, Hampshire I can bend it for you

Cheers
David

m8kwr - 29/7/10 at 11:49 AM

I saw a video of a person using duck tape, filling the tube with water, then putting sand in, duck taping the other end up and then bending it, to try and stop it kinking etc.

Looked very messy..

HTH

goaty - 29/7/10 at 12:11 PM

quote:
Originally posted by m8kwr
I saw a video of a person using duck tape, filling the tube with water, then putting sand in, duck taping the other end up and then bending it, to try and stop it kinking etc.

Looked very messy..

HTH


dont think it will really work properly, will still kink as the sand will push out. if it is a roll cage do i right is the way i look at it....

splitrivet - 29/7/10 at 12:17 PM

As said bag of block paving dry sand should sort you, fill the tube tape the ends up and pray hesto.
Cheers,
Bob

MikeR - 29/7/10 at 12:20 PM

The sand is packed in very tightly and has a lot of friction, As long as the end of the tube is a distance away, duck tape does hold it (i've seen probably the same video).

liam.mccaffrey - 29/7/10 at 12:41 PM

I'm in Wales I can do it for you.

But you're in Yorkshire

[Edited on 29/7/10 by liam.mccaffrey]

Davedew - 29/7/10 at 02:13 PM

I have just finished building my rollcage using 50.8mm O/D x 3.2mm wall ERW.

I only had a hydraulic pipe bender to hand. The only way I found of doing it was to cap the ends of the tubes, and pack full of sand. I then heated it until cherry red to bend without kinking.

Hope that helps

pre lit - 30/7/10 at 09:18 AM

bent the first one cold no sand.then filled tube with sand and bent the second one no kinking and job looks a good one thanks for the advice