CaveLamb wrote:
Jon Elson wrote:
Tim Wescott wrote:
Yes, there's a lot of different alloys that can be tempered to T6 --
so feel free to educate me.

Is it at all a sensible thing to think that I could get some 40 - 60
mil aluminum sheet that's already tempered to somewhere between T3
and T6 (harder is better), and be able to put 45 degree bends in it?
60 degree? 90? Bend radius? Is this something that could be done on a
normal brake? Clearly springback would be an issue, but is it just a
pain, or a real @#$% pain?

Or did I accidentally smoke something this morning, and do I just
have to get some decent alloy in an annealed condition, bend it up,
and figure out how to bake it?

You can probably get by with 6061-T6, especially if you don't set the
brake for a sharp bend. No way on earth
with 2024, it will snap almost like glass. With the 6061, you can heat
it along the bend line with a torch until
a soap streak turns brown, then immediately hold under running water.
This will anneal it so it can be easily
bent, even 1/8" thickness. It will re-harden over time. (Heat treat
can be hurried with an oven, of course.)

Jon


I've never heard of the running water part before.

What I did was mark the bend area with a marks-a-lot and burn it off
with a PROPANE torch. OA will burn it off - along with the metal -
if you are not really really careful.





A propane torch is hot enough for most applications. The cold water
does a better quench to soften the aluminum. You can bend 2024 is your
are careful and don't try for a square corner. two backup strips of the
same gauge will usually keep it from cracking especially if you anneal
it. When I was doing STC's for autopilot servo installations I would
order the metal in the annealed condition T0 and then after it was
bent it would be sent to an approved heat treat company but that would
probably be too expensive for your application.

John