pipe benders for aluminum

And with aluminum pipe and a full 90-degree bend, unless it's annealed dead-soft at the beginning of the bend, and possibly annealed once or twice more as you stop in mid-bend, you *will* get cracking in the pipe.

Aluminum doesn't stretch worth a darn, it rips. If you need more than a few degrees of bend, it may need to be cut into wedge segments and welded.

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I don't know about Schedule 40, but I bent a bunch of 1" ID 1/16" wall

6061 thinwall tube by wrapping it around a 1000 lb drum of communications cable. Granted, not everyone wants a 20" bend radius on their parts, but it worked for what I needed (gripping a rubber ball with a 40" diameter).

On the construction job I once worked on, the electricians bent aluminum up to 4" daily with their benders. Of course the aluminum rigid conduit might well have been a special alloy.

RJ

The vast majority of electrical work you would see in the US is done with thinwall mild steel Electrical Metallic Tubing, or heavy-wall seamless (mandrel drawn) Rigid Steel Conduit that is threaded in standard pipe sizes. Both are galvanized to resist the effects of water.

Both of those conduits bend up nicely, because the steel allows for easy bending without failures. You can do it in dead-soft aluminum, but not aluminum pipe that is many years old - just age alone will start to harden some alloys.

Aluminum conduit is avoided, because when it gets wet and/or attacked with alkali soil and pool chemicals and fertilizers it quickly rots away to a jelly or oxide crumbles. Been there a few times (when people tried homemade parts) and had to replace the whole thing.

If you have corrosive or 'special' conditions, or underground, you use gray PVC plastic conduit for the wiring.

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I bought a 16 ton air/hydraulic bender with dies up to 3" yesterday. I tried it on some 3/4" sch 40 aluminum and it cracked wide open, also

3/4" sch 40 steel pipe kinked/folded . If I try to anneal the aluminum with my oxy/acetelyne torch how do I know how hot to get it and do I just let it cool in the air? Would annealing the steel pipe make any difference. Thanks

Maybe you are using the wrong die. The pipe should fit fairly snug in the die, if there is too much wiggle room side to side it will kink. If there is too much room and you are using the closest die you have, you may have some luck by using shims in the die. shims can be plate steel or sometimes plywood.

Did he ever say how tight a bend he's trying, or needing, to make? All this is so if he wants a one-shot bend. If he can settle for a long sweeping bend he could do it in several smaller incremental bends.

Quick-N-dirty anneal.

Soot the area to be annealed, with an acet flame. Heat till all gone.

Or, scribble on area with Sharpie marker, heat till gone.

Not perfect, but it works.

Cheers Trev

There might be 1/16" of play but I am using the right die. I also tried 1" sch 40 and it bent well but flatened out a tiny bit.