I have two 12.5 foot pieces of one inch square aluminum tubing and two 6.25 foot pieces. These are going to be put together with corners and ears to build a frame for a screen for a ultra short throw rear projector.

I had the tubing cut and delivered and it is covered in aluminum oxide maybe? Anyone have ideas to get them clean? I have tried denatured alcohol and paper towels and no matter how much I go over it, there is always more black stuff coming off.

Are you sure that's aluminum, it looks like steel covered in grease to me. Use a degreaser then coat it with paint or something else so it won't rust.

It is a black coating to prevent oxidation for use in outdoor applications, I believe.

Does it wipe off when you don't use alcohol?

Probably need a mechanical method to remove it, but you should probably leave it if it doesn't rub off on everything.

You are right. I ordered aluminum but it says steel on the receipt. Rats.

I don't know whether you're going to stay with the steel or not, but if you don't, be sure to order 'anodized' aluminum tubing (instead of mill finish) if you don't want the black aluminum oxide present on the surface.

You can remove the oxide, but if you don't treat it or coat it the oxide will re-form.

At one time, we had to fabricate some assemblies from 16 gauge aluminum tubing and we started by joining the corners by welding them.

That was time consuming and a PITA, at least for our application. Instead, we bought pre-made corner 'L's, 'T's, and 'Crosses', and it simplified things tremendously. Perhaps that's what you're going to do, too. I dunno.

Good luck.

Ended up sticking with steel. Degreased with zep purple and scrubbing brushes. Then went over it with 220 grit sandpaper. Rustoleum primer is drying while I drink beer down the street.

First attempt at hanging the screen. The bungee cords were to tight and I need to figure out the corners.





Tried playing Mario but there was controller lag.