Help Aluminum Bar

[dbreeze225]

hey guys so i got one of the alluminum bar about a inch wide and 4 feet wide now i cut it in smaller size and i was in the process of making some 90 degree bends in it for what i need and the second to last bend almost broke off i could just feel that i went a lil to far and you can see a hairline crack in it but it is still togather this piece is being hung on wall and light weight hung from it (not to much weight just a few leather sheath's from a couple knives) i just dont want it to compleatly break do i just need to start over (really dont want to do that)  can i strengthen that bend some how to make sure it wont break i was thinking maybe putting a lil "jb weld clear weld" epoxy on and around would than make it stronger? any advice would really be apreciated

[PixMan]

What grade of aluminum is it? The common 6061-T6 doesn't take to bending well. That's a job for 5052 or other. You can bend 6061-T6 if you pre-heat it, but I'm ignorant about how much heat.

Fixing the cracks you have isn't easy and may not be worth the effort. TIG welding would be the better choice, though tedious and expensive.

[Roadracer_Al]

PixMan, you make welding sound like a drag.   dbreeze, If you have a friend with a TIG welder, they could do that for you in a couple minutes.

What you want to do before bending is called "annealing".  It is a process of removing hardness from metal - it could be hard from working (your case) or hard from heat treatment (i.e. the T6 condition).

Different metals have different processes for annealing, and some of them are completely the opposite of the other --- for example, many types of steel harden if you heat to cherry red and quench, but copper becomes dead soft if you heat to red and quench.

For aluminum, there are 2 reliable methods for annealing.  First, if you have an oxy-acetylene torch, you begin by lighting the torch with only the acetylene and covering the part to anneal with soot from the acetylene flame.  Then, turn on the oxygen and balance to a slightly rich flame, and burn the soot off.  Et Viola, soft aluminum.

The second method is to use an ordinary bar of hand soap, and rub it all over the aluminum to be annealed.  Use a propane torch to burn off the soap. It'll turn ugly brown first, but will quickly burn off.  Once it's clean, it's soft.