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Straightening aluminium

Posted: Sun Oct 19, 2014 6:40 am
by Norm
Not Enfield but late model Triumph brake lever that has been bent in a 180 degree hook.They must be made of beautiful alluminium because even though it has turned into a "U" shape and the ball is still on the end. It is obviously not diecast so does anybody have any ideas as to how it could be straightened. I assume heat will help.I'm contemplating clamping the ball end to the bench and heat it and drawing it backwards. Any other thoughts. I'm more interested in seeing what good ally is capable of doing

Straightening aluminium

Posted: Sun Oct 19, 2014 8:12 am
by Leon Novello
I don`t like your chances, Norm, those poor little molecules have been stretched to their limit in one direction, I don`t think they will like going all the way back without snapping. Best of British luck.

Straightening aluminium

Posted: Sun Oct 19, 2014 8:17 am
by Norm
I know Leon it is just amazing seeing how it has bent, certainly made of good ally

Straightening aluminium

Posted: Sun Oct 19, 2014 8:41 am
by sa(lincs)
Hi Norm
Anneal it by heating till a match rubbed along it leaves charred line,then quench or leave to cool slowly ,either way it will soften until work hardened again. you can also rub soap along it before heating and when that turns brown its at right temp.
good luck

Straightening aluminium

Posted: Sun Oct 19, 2014 10:17 am
by Gwilly
Norm, i'm sure it would be an interesting exercise to see if it could be done, and the use of soap to gauge the temperature range is the way to go...

However to be blunt, the idea is fraught with danger.. Grabbing a handful to avoid a roo could make a person wish he spent a few dollars on a new one...

Just saying is all Norm, not wishing to be a party poop..

Straightening aluminium

Posted: Sun Oct 19, 2014 10:50 am
by simon
I have a memory of the metal work master at school telling us to soot up the surface with a pure acetylene flame and then burn it off with a oxy-acetylene one. Never tried it though.

Straightening aluminium

Posted: Sun Oct 19, 2014 11:49 am
by Vespa66
Hi Norm and all, as it happens there is a short article with pics on this exact subject in the August issue if the classic bike magazine here in the UK. It is same as guys on here have said using soap and annealing . I'd be happy to email it to you Norm if you can't get the mag locally .
Vespa66

Straightening aluminium

Posted: Sun Oct 19, 2014 4:53 pm
by Norm
Thanks everybody for your help and ideas, will see how it goes for just the hell of it. Gwilly you party poop, don't worry this point has well been discussed.
Hi Vespa that would be nice if you don't mind and not too much trouble email me at bikernorm1947atyahoo.com.au the at is @. thanks again

Straightening aluminium

Posted: Sun Oct 19, 2014 6:47 pm
by PeteF
If there are no cracks at all then you should be able to anneal it. When straightened, anneal it again then squeeze it as hard as you can to test it.

Straightening aluminium

Posted: Sun Oct 19, 2014 7:18 pm
by simon
Yes Pete is right aluminium work hardens so you will need to continually anneal it during the process of straightening.