[Richard Wallace]

I'm an electrical engineer, too, so consider the following with healthy skepticism:

You might consider 1/16th inch wall steel tubing as an alternative to solid aluminum. At 3/4" o.d. this wall thickness would give about the same weight per foot. Steel has two advantages: (1) compared with aluminum, there is more margin between the yield and ultimate strengths of steel, so you run less risk of breaking the stock while you try to bend it, and (2) the finished hollow steel piece will be stronger than the solid aluminum. The force required to bend the steel will be about 50% higher than what you'd need to bend the solid aluminum.

I have heard that thin wall steel tubing can be bent to smaller radii without too much risk of buckling if you first fill the section to be bent with Bismuth Alloy -- the alloy will melt at a fairly low temperature (maybe 120 to 180 deg F?) and after you form the bend you can melt the alloy out again using hot water.