How to unbend aluminum bumper

[BigR]

Hi All,

Looking for bumper options for my 544 Volvo "lead sled". The original ones are old, dented, and too big, especially with the overiders. So far I have tried on Morris Minor front and rear and old (non BMW) Mini bumpers, that were donated to me. They weren't right.

Here is the look I'm going for, see pics. Not my Volvo. The blurb on the car pictured said that the bumpers were VW items that he straightened and adjusted for fit. You can see how much of a curve they have from the pic of the Bug. I can get the VW billet aluminum bumpers from a number of places for about a hundred apiece.

The Briz ribbed aluminum ones look good to me but of course they would be expensive. Also I need to know how the bumper looks on the car, and make adjustments as needed.

Here's my question: How do I take the center arc out of the billet aluminum VW bumpers? The Bug front and rear is curved, while the Volvo has more of a flat face and tail. There must be a way using weight, a floor jack, winch, etc. to take part of the curve out. I'm counting on them to be sort of flimsy anyway. Probably would get bent easily in a parking lot encounter.

Naturally using heat is out of the question, can't control it that well, and aluminum melts instead of glows when it gets too hot.

Looking for a rat rod low buck fix, not interested in the "Take it to so and so's shop, they are experts" answers. This is MY build. Easy to throw money at a problem, not my style. I wanna do it in my garage; the fun is in figgerin' out and fixin' the problem. This is a cut and try operation. I have lots of patience. If I mess it up, then I've learned something.


John in Prescott.

[kenny c]

Haven't worked with them but you could try putting them in a press and working them a little at a time. If you don't need the ribs a set of 40 ford bumpers may do. They are steel and you could paint them any color you like.

[Sam_Fear]

"take it to a shop." BAH! You won't hear that around here to often.

Rolling it might work? But I'd be afraid it would mar the surface. Maybe a wooden jig to press it into shape? Most anything else seems like it would run the risk of bending in one spot.

[Dr Crankenstein]

Just a semi-educated thought or three...

It depends a lot on what the bumper is actually made of. ("Billet" doesn't tell you the alloy or grade of the material.)

At $100 each, I suspect they're rolled from a relatively light, soft alloy extrusion. (If that's the case, you can probably bend it over your knee.)

"Harder" alloys require heavier equipment to form. (You're not likely to bend a heavy 6061 or 6063 piece at home without cracking it.)

Anyhow, I wouldn't be afraid to mess with the $100 bumpers. I'll bet they'll bend easy as a coat hanger...


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[anvil]

The way to tell if the temperature is right for forging aluminum. A pice of hard wood slips. Yes it melts before color.

[BigR]

Well, if I was still in Kalifornia I could probably find a "Cal Look" VW Bug with these bumpers on it. That way one could find out how easy it would be to bend the extruded metal. This would require, of course, someone to distract the owner while the experiment was taking place. I doubt they are made of some strong alloy.

John in Prescott

[Bamamav]

If you have access to a press, it would be pretty easy to block and press a little at a time until you get what you want. I had an aluminum door off my headache rack get bent, I used the dolly on my loaded semi trailer to press it back into shape. A lot of crank twisting, but it got the job done. In a pinch, you could do it with a hydraulic jack and something heavy to press against.

[BigR]

Here is how I took the excess curve out of the trunk lid on the Volvo. I cut some wood blocks to support the ends of the lid, following the contours of the edges. Then I used a big padded wood block as a press. The weight of the car provided the force. Don't know why can't use the same general idea for the bumpers. They would be much easier to bend.

John in Prescott

[Tripper]

Originally Posted by BigR

Here is how I took the excess curve out of the trunk lid on the Volvo. I cut some wood blocks to support the ends of the lid, following the contours of the edges. Then I used a big padded wood block as a press. The weight of the car provided the force. Don't know why can't use the same general idea for the bumpers. They would be much easier to bend.

Sometimes the simplest way is the best!

BoB

[Dr Crankenstein]

Originally Posted by BigR

Here is how I took the excess curve out of the trunk lid on the Volvo. I cut some wood blocks to support the ends of the lid, following the contours of the edges. Then I used a big padded wood block as a press. The weight of the car provided the force. Don't know why can't use the same general idea for the bumpers. They would be much easier to bend.

John in Prescott

Sounds like a plan.

Originally Posted by Bamamav

I used the dolly on my loaded semi trailer to press it back into shape.

Pomona CA 1998: We badly boogered the body latch (among other things) on our funnycar. We used the same method to straighten it out!

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