Corrosion question

[1planeguy]

I came across a couple of sheets of 6061-T6 and want to use them in my Sonex project but they have a few patches of corrosion. These were stored in a basement that had some moisture issues for several years and have a few sketchy places. Plan A is just cut parts from clean areas of them...but wondered if there might be a way to save it. A quick scrub with a scotch-brite pad didn't seem to budge it...any ideas?

[Bryan Cotton]

Plan A is a good one. If I was going to try and save it I would use the right angle sander with either fine grit or scotch brite and see what it took to clean up. In the certified world AC43-13 gives you 10% to work with. If it is .025 it can end up as .0225 and still be ok. If it is deeper than that then you have to reinforce it or in this case I would not use it.

[SvingenB]

Hard to see from the picture, but it looks like it's just a surface thing, combination of water staining and crevice maybe. Scotchbrite should get it, you just have to use some force. The parts that are (water) stained does no harm, it actually improves further corrosion resistance. Remember, this is 6061 not 2024 alclad. When out of the damped basement, it's not likely to get worse in a million years