Milestone and Spar Cleaning / Corrosion Protection Question

[alexM]

Etch and Alodine is absolutely safe but you need to be able to rinse it really well. Kind of tough to do on a built up wing, especially if the ribs aren't varnished yet. From where you're at I would probably stick with the red scotchbrite pad, clean well with acetone and use the two part rattle can epoxy primer that Jerry suggests. I've got a couple fresh cans that just arrived here yesterday. That stuff sprays on better than I ever thought I would see from a rattle can.

I've come to the conclusion that I'm way more worried about the way the wood ages vs the aluminum. My Citabria had lots of both materials (and a lot of 4130) and I can tell you the aluminum was doing better than the wood in terms of fighting off moisture over a period of 5+ decades. To that end I have made epoxy varnishing my new hobby.

I did etch and Alodine every piece of aluminum before building my wings and that is where I'm going to stop.

[tim.green]

Alex and Jerry - Thanks! Great information! Super helpful - this forum always delivers!

Which specific primer are you guys using? Can you provide a brand or a link?

Thanks!

Tim

Etch and Alodine is absolutely safe but you need to be able to rinse it really well. Kind of tough to do on a built up wing, especially if the ribs aren't varnished yet. From where you're at I would probably stick with the red scotchbrite pad, clean well with acetone and use the two part rattle can epoxy primer that Jerry suggests. I've got a couple fresh cans that just arrived here yesterday. That stuff sprays on better than I ever thought I would see from a rattle can.

I've come to the conclusion that I'm way more worried about the way the wood ages vs the aluminum. My Citabria had lots of both materials (and a lot of 4130) and I can tell you the aluminum was doing better than the wood in terms of fighting off moisture over a period of 5+ decades. To that end I have made epoxy varnishing my new hobby.

I did etch and Alodine every piece of aluminum before building my wings and that is where I'm going to stop.

[alexM]

This stuff
PXL_20210814_210708341.jpg
It's not cheap but it's a great product. You shake it up, insert a supplied plastic plug into the bottom of the can and press it in. This breaks the seal between the 2 parts (2K means two part I guess), shake it quite a bit more. Then you have something like 3 days to use it up. That time varies between the primer and the clear top coat they sell.
You can find it on Amazon if you can't find it at a local body shop.

[tim.green]

Thanks Alex. I ordered two cans just now! I appreciate your help!

This stuff
PXL_20210814_210708341.jpg
It's not cheap but it's a great product. You shake it up, insert a supplied plastic plug into the bottom of the can and press it in. This breaks the seal between the 2 parts (2K means two part I guess), shake it quite a bit more. Then you have something like 3 days to use it up. That time varies between the primer and the clear top coat they sell.
You can find it on Amazon if you can't find it at a local body shop.

[JeffKinMT]

Do you guys plan to treat the inside of the spars? I'm getting close to this point in my build and have seen differing opinions...