Another RV-10 Priming thread - First one this month!

Also in the planning stage for an RV-10. Will be building this about 1 block from the ocean... Yeah if any of y'all come to Ocean City MD hmu.

Anyways, I'm on the other side of the spectrum. I don't have space for a spray booth and I'm not convinced that going all out with two part epoxy primers compared to rattle cans justifies the extra work involved. Especially if I'm not aiming for a forever plane, but maybe 30 years with active corrosion management. (application of corrosion-X, checking for corrosion and correcting every condition inspection etc)

What is the minimum viable amount of primer I should apply? I'm hoping for rattle can self etching primer, the simpler the better. But if the consensus is that I really should do two part epoxy primer, is it possible to farm the work out to someone that has the equipment? I was thinking like a body shop or someone like that.

Suggestions and comments? I know that this is a topic debated to death, but a lot of old threads always have the qualifier "...if you're not near the ocean..." so I wanted to get some opinions on what everyone thinks the least a builder should do if they're right on the ocean.

Edit: A bit of digression on primers and more on corrosion prevention, will a dehumidifier in the garage be helpful during the build process to minimize corrosion?

Minimum primer

If you want minimum try SEM or NAPA 7220 and only on mating parts, 6061 and steel. Spray thin. Some components need full coverage like 6061 and steel. Check the manual.
Yes, anything you can do to dry the work space would help keep corrosion from starting. Check edges regularly. It typically starts under the edge of the blue vinyl.

I've used SEM for the whole build. I probably put a bit more than required on it, but you can still see a bit of silver shine through. Doesn't take much and is super easy to apply and has been very durable thus far.

majuro15 said:

I've used SEM for the whole build. I probably put a bit more than required on it, but you can still see a bit of silver shine through. Doesn't take much and is super easy to apply and has been very durable thus far.

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Do you still plan on doing corrosion treatment every year? When you apply it, do you just wash and spray or do you do some sanding?

wirejock said:

If you want minimum try SEM or NAPA 7220 and only on mating parts, 6061 and steel. Spray thin. Some components need full coverage like 6061 and steel. Check the manual.
Yes, anything you can do to dry the work space would help keep corrosion from starting. Check edges regularly. It typically starts under the edge of the blue vinyl.

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Is there a particular SEM you recommend? I did a quick google search and it seems to be a company.

wirejock said:

If you want minimum try SEM or NAPA 7220 and only on mating parts, 6061 and steel. Spray thin. Some components need full coverage like 6061 and steel. Check the manual.
Yes, anything you can do to dry the work space would help keep corrosion from starting. Check edges regularly. It typically starts under the edge of the blue vinyl.

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6061 has inherently better corrosion resistance than most other aluminum alloys. It's debatable if you need to protect parts made from it. Here's an Alcoa data sheet on 6061 I found. It says it has good corrosion resistance to seawater.

I know the Sonex line of aircraft are made from 6061. If I was building a Sonex I wouldn't do any additional corrosion protection. However, I live in a dry climate.

Manual

StressedOut said:

6061 has inherently better corrosion resistance than most other aluminum alloys. It's debatable if you need to protect parts made from it. Here's an Alcoa data sheet on 6061 I found. It says it has good corrosion resistance to seawater.

I know the Sonex line of aircraft are made from 6061. If I was building a Sonex I wouldn't do any additional corrosion protection. However, I live in a dry climate.

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That's why my comment includes "Check the manual". Mine mentions priming 6061 parts but feel free to leave them as you wish.

SEM

echozulu said:

Is there a particular SEM you recommend? I did a quick google search and it seems to be a company.

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Hopefully a SEM user will make recommendation. I use P60G2. I suggested it based on other builder recommendations.

I order SEM self-etching primer in rattle cans from Summit Racing - best price I've found. The regular (non-rattle can) is available as well. I use gray (started with green, switched to gray when I started painting interior parts because colors look better over gray) - here's a link to it on Summit's site: https://www.summitracing.com/parts/smm-39683

I live near the ocean and I have been priming all interior parts like ribs, everything non-alclad (and parts Van's recommends priming, especially steel parts / inside of pushrods etc), and mating surfaces of skins. Also bottom skins where moisture might collect.