by uscgairdale » Thu Jan 04, 2007 6:16 pm
I always bend perpendicular to the grain too as it really does make a diffence. Anyone whos tried to bend parallel to it gets an unwelcome suprise when they are half way through the bend.
My previous ul project was a plans built Hummel CA-2 so I've spent some time bending aluminum. I don't claim to be an expert, but I've experienced a fair bit of manipulating metal. Generally, the thicker the material, the larger the radius required. You can "get away" with less of a radius with thinner material. 6061 T6 bends real well, 2024 T3 is harder to bend, and 7075 T6 is harder to bend still.
Identifing the grain is harder on certain alloys. If you can't see it, there are other ways to tell. If the piece is large enough, you can look for the manufacterer/alloy/material thickness stamp. It's always put on the sheet parallel to the grain.
.080" is really thick stuff. Maybe two .040" thick plates stacked on top of each other would be acceptable and easier to fabricate?.......