Need ideas on bending aluminum.

enjenjo · May 25, 2004, 01:29:39 AM

I am making a piece of trim, from billet aluminum, when done it has to be bent to fit the curve of a hood, a large radius, 2 to 3 ft.

The trim is thicker and wider at the front, about 1 1/2" wide, and nearly an inch thick, and it's about 1/2" square at the rear. The piece needs most of the bend at the front, not much at the rear.

Any suggestions?

nzsimon · May 25, 2004, 04:02:49 AM

Why not make it out of balsa then get it cast in either alloy or brass and get it chromed will look much better chromed than polished alloy will ever look

Leon · May 25, 2004, 04:27:49 AM

I agree that a cast piece would look better. If you do use aluminum make it out of an alloy like 3003 that can be worked better after anealing. If you use something like 6061 it will probably crack at that thickness

SKR8PN · May 25, 2004, 07:14:55 AM

Can you make it out of stainless?? No need for chroming when you are done,just polish it. Stainless works pretty easy,you could shape it with a grinder and a D/A,and you could probably bend it between a couple pieces of pipe welded to your work bench.
$.02

GPster · May 25, 2004, 08:35:55 AM

I would assume that because this is going on a hood, it will be flat on the hood surface side. Can you cut the hood profile on a 2 X 6 (1 1/2 x 5 1/2) so that you have something solid to form it to? I don't know if there is any "spring-back" when bending aluminum but you can trim your form if you need more. I imagine it being bent to the form with "C" clamps from one end to the other. Think of the bend being accomplished more like an eletrical condiut bend than a structural steel bend. GPster

enjenjo · May 25, 2004, 09:29:43 AM

Quote from: "nzsimon"Why not make it out of balsa then get it cast in either alloy or brass and get it chromed will look much better chromed than polished alloy will ever look

We no longer have a foundry locally, but that is not a bad idea. Some time back I had to repair or replace a tail light stand, looked into geting one cast, and I couldn't find any one interested. I'll give this one some more thought.

enjenjo · May 25, 2004, 09:36:00 AM

Quote from: "Leon"I agree that a cast piece would look better. If you do use aluminum make it out of an alloy like 3003 that can be worked better after anealing. If you use something like 6061 it will probably crack at that thickness

Unfortunately the material I have is 6061 :cry: I did some testing with a scrap I have here, and it appears it will bend enough for my purposes.

I do have a large pinch roller, I might try bending it with that. My idea there is to make the area where the most bend is needed thicker, so it with change radius naturally when rolling. I have two pieces to work with, so I can only sacrifice one

enjenjo · May 25, 2004, 09:40:24 AM

Quote from: "SKR8PN"Can you make it out of stainless?? No need for chroming when you are done,just polish it. Stainless works pretty easy,you could shape it with a grinder and a D/A,and you could probably bend it between a couple pieces of pipe welded to your work bench.
$.02

I am concerned about weight, this is a base to support a neked lady hood ornament that weighs a couple pounds, and in stainless, I thinkit would be heavier than I want. I have pretty much ruled out brass or copper for the same reason

enjenjo · May 25, 2004, 09:44:48 AM

Quote from: "GPster"I would assume that because this is going on a hood, it will be flat on the hood surface side. Can you cut the hood profile on a 2 X 6 (1 1/2 x 5 1/2) so that you have something solid to form it to? I don't know if there is any "spring-back" when bending aluminum but you can trim your form if you need more. I imagine it being bent to the form with "C" clamps from one end to the other. Think of the bend being accomplished more like an eletrical condiut bend than a structural steel bend. GPster

I have been considering this too Joe. My though was a metal form, so I could use a bit of heat to help it along. I'm thinking that I could clamp one end tight to the form, put some pressure on the other end with a clamp, and heat it, while pulling it down to conform to the pattern.

C9 · May 25, 2004, 09:53:30 AM

Could you do something along the lines of cut multi-kerfs, bend and weld back together?

Weld the kerfs completely, smooth them down and polish.

This done in the thick area only - it looks like your roller would take care of the subtle bend required in the middle and back, unless that area is all flat.

enjenjo · May 25, 2004, 10:28:51 AM

Quote from: "C9"Could you do something along the lines of cut multi-kerfs, bend and weld back together?

Weld the kerfs completely, smooth them down and polish.

This done in the thick area only - it looks like your roller would take care of the subtle bend required in the middle and back, unless that area is all flat.

That may be necessary to get the shape I want using the roller. The curve goes the full length of the peice, more radius at the front, less at the rear.