superficial corrosion under wing

[Marc_B]

I have some small areas around a few access panels with some corrosion and some paint chips around some rivets/leading edge.  I'm planning a full repaint which would completely address these areas.  But I'm trying to figure out when it makes the most sense to address.  Is this something that can wait a year or two, something that should be temporized now, or something that I should address as soon as practical?  My Mooney spent a period of time on both coasts with previous owners; it's now in northern Colorado and lives in a hangar.  Inside wings look great and have had CorrosionX applied, so no corrosion concerns other than 2-3 access panels with what you see.

Thanks,

Marc.

[DCarlton]

I'm not an expert, but I have a few similar small issues that I'm starting to address.  My questions surround how best to metal prep smaller areas before paint and then what paint to use for top coat touch ups (two part polyurethanes or something more convenient like an enamel).  I'm using the.... "something that I should address as soon as practical" philosophy.  Will be interesting to see what the experts say.  

[N201MKTurbo]

50 minutes ago, Marc_B said:

I have some small areas around a few access panels with some corrosion and some paint chips around some rivets/leading edge.  I'm planning a full repaint which would completely address these areas.  But I'm trying to figure out when it makes the most sense to address.  Is this something that can wait a year or two, something that should be temporized now, or something that I should address as soon as practical?  My Mooney spent a period of time on both coasts with previous owners; it's now in northern Colorado and lives in a hangar.  Inside wings look great and have had CorrosionX applied, so no corrosion concerns other than 2-3 access panels with what you see.

Thanks,

Marc.

The service manual 20-00-02 addresses corrosion repair. What you have is filiform corrosion, which is surface corrosion under the paint. I would fix it sooner than later. I would use a plastic scraper to strip the paint off the corroded areas, then using the methods from the manual, use scotch brite to clean the corrosion off to good metal, prime with zinc chromate.

[A64Pilot]

In my opinion anytime you strip to bare metal treating corrosion, you should alodine. It’s easy, not all that expensive and really works well.

As to now or wait until re-paint? I’d say wait, that took years to get to where it is and as your in a dry climate and hangar stored it shouldn’t be progressing or if so very slowly, one assumes you are having someone paint that knows what they are doing.

Don’t apply anymore Corrosion-X though until after the paint job, it penetrates really well and makes painting difficult.

[Marc_B]

@A64Pilot That's kinda what I was trying to figure out...if it's slow progression and I can just wait til repaint (planning on within next 1-2 years depending on schedule), then I'd rather wait and have it fixed right.

[DCarlton]

23 hours ago, N201MKTurbo said:

The service manual 20-00-02 addresses corrosion repair. What you have is filiform corrosion, which is surface corrosion under the paint. I would fix it sooner than later. I would use a plastic scraper to strip the paint off the corroded areas, then using the methods from the manual, use scotch brite to clean the corrosion off to good metal, prime with zinc chromate.

Can you still buy zinc chromate in AZ ? 

[EricJ]

25 minutes ago, DCarlton said:

Can you still buy zinc chromate in AZ ? 

Zinc phosphate these days.

[N201MKTurbo]

5 hours ago, DCarlton said:

Can you still buy zinc chromate in AZ ? 

You can still mail order it I think. I know it is hard to come by. It’s sad, it worked so good. Zinc phosphate goes on much thicker and takes days to dry.

[N201MKTurbo]

https://www.amazon.com/MARPAC-MARINE-Chromate-Primer-6-5605/dp/B00ZSY2P3I/ref=sr_1_2_mod_primary_new?keywords=zinc+chromate+primer&qid=1667423810&qu=eyJxc2MiOiI0LjU3IiwicXNhIjoiMy4yNCIsInFzcCI6IjIuOTgifQ%3D%3D&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=8-2
 

 

[DCarlton]

2 hours ago, N201MKTurbo said:

You can still mail order it I think. I know it is hard to come by. It’s sad, it worked so good. Zinc phosphate goes on much thicker and takes days to dry.

It does go on thick and take forever to dry.  First time I used it, I didn't think it would dry.