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Old 12-06-2018, 01:53 PM
crystallographic crystallographic is offline
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Quote:
Originally Posted by Smash bang View Post
I have an Airstream 345 motorhome that got bumped in the rear.
The bumper got pushed in about 3 inches and I want push it back
to it's original shape. They are extruded aluminum about .2 inches
thick. They are in the shape of a channel. I have a 55 ton arbor
press available.

I have been thinking about the best way to do this. I think that
I will make some wooden blocks that conform to the original
shape and use them with the press.

I have seen some amazing results in straightening alloy wheels
but they heat them. Should I heat the bumper? What temperature?

Thanks.

Hi SmashBang,
Note that wheels are Cast aluminum and bumpers are Extruded. Very different critters. Okay?
Try heating a 4in area of your bumper to 650F using a temp crayon or an IR gun.

You DO have to be accurate with heating aluminum alloys.
Spray water on the spot when done heating.
You do NOT have to heat it for a long time, just get it to the temp and cool quickly.
Give it a bang with your smash hammer and see if it goes in that direction, using a wood table to smash on - NOT steel, NOT concrete, NOT rock or stone.
If it does then you have an alloy that anneals at 650F, and you can continue straightening.
Danger Will Robinson!!! Danger! Do not over heat, or heat too long in one spot.
Good luck.
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