Cleaning oxidation off T6-6061

[Ron in SC]

My friend is giving me a piece of 1/2" aluminum to make a 26" x 72" bench top. I'm going to screw it to a 2" thick hardwood top, the kind Sam Club sold with 6 legs.

Would it be ok to have the aluminum top extened beyond the edge of the hardwood top on the back, sides, or front? Or would that make it to easy to break off if it got hit hard with a hammer.

What do I use to clean up the aluminum? Wet/dry black sandpaper maybe?

[Rocky D]

I would have it hang over about 4 inches so you can clamp to it.. Naval Jelly is good for cleaning aluminum.

[projectwelder]

Rocky always has good advise! If chemicals are not your thing, a green scotch brite pad works better than the sand paper.

John

[imagineer]

Or would that make it to easy to break off if it got hit hard with a hammer.

What do I use to clean up the aluminum? Wet/dry black sandpaper maybe?

It most likely won't break, but it will bend easily. When you attempt to bend back 6061-T6, it will crack if you don't use some heat.

Scotchbright (red) would be the best for cutting through the oxidation. It seems silly, but apply & buff a couple coats of paste wax on the work surface. It will make things easier to slide and also help prevent gray marks on stuff put on the bench.

It might cost you a few bucks, but if there is an anodizer near you, have them acid dip the panel (to clean it) and then anodize to a 204-R1 finish (think Wal-Mart storefront door finish). The anodize coating won't last forever, but it will make the top look and work better.

[Rocky D]

1/2" T-6 won't be easily bent with a hammer. Especially used as a top supported by wood.
I recently got some phosphoric acid from the Orange apron guys, and it worked great to clean a fairly new piece of 1/2" T-6...I used it full strength and wiped it right off...I think a safer solution would be to dilute it 50% with water. Its powerful stuff!

[Ron in SC]

I picked up the sheet of aluminum and it's a 4' x 8' sheet, very heavy. It was oxidized quite a bit on one side. It was laying flat on other scrape metal full of leaves and water. I used full strengh muriatic acid to clean that side.

The other side is not heavily oxidized but it certainly is not smooth, it has some light pitting. I'm thinking of using my grinder with one of those burgendy color scotch brite pads and just do a swirl finish over the whole top. I've seen somthing like that in elevators but I'm sure some kind of machine does that finish.

Since the aluminum sheet is not very smooth even on the better side I think it would be to much trouble and effort to polish it real smooth.

Any other suggestions?

[Pangea]

Knock the high spots off of it and call it good. If you do enough work to need a table top like that, it'll look rough in two months anyway.

When I was in the USAF we had 1/2" thick copper table tops. Talk about stabilize a low amp arc RFN!

[Ron in SC]

If you do enough work to need a table top like that, it'll look rough in two months anyway.

I know that's true but I'd kind of like to have have it at least start off looking real nice.

I have tried to polish and also sand it with my belt sander using a 40 grit belt and all I can say is I know this stuff is aluminum supposedly 6061 but it sure is hard. I can not really leave I groove in it if I leave the sander in one place for a while.

[usmcpop]

Use some Easy-Off oven cleaner. Watch your eyes. Get a brick and throw a handful of sand on there at the same time. Rub, rinse and repeat. Done.