I decided early on that I'm going to prime my RV-7. I'll probably be flying this airplane for a long time, and I don't know exactly where I'll be taking it. No matter where it goes, I want it to be protected from corrosion for its entire life. Plus, if I ever do decide to sell it, priming will most likely add value in the eyes of a buyer. Priming definitely adds cost and (a LOT of) time to the build, but the benefits are worth it in my opinion.
I ordered some AKZO epoxy primer a while ago from Aircraft Spruce at the recommendations of quite a few builders on the VAF forums. Unfortunately, it was on backorder and wouldn't arrive for around a month. I decided to wait until after priming to dimple the pieces to avoid tearing up my Scotchbrite pads and to make it easier to apply an even coat of primer across each piece. The AKZO is pretty bulletproof once cured, so dimpling after it's applied shouldn't be an issue.
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| The containers were a little beat up during shipping even though they were thoroughly encased in cardboard and plastic, but the contents are just fine |
The AKZO arrived a few days ago, so I went out and bought a bunch of priming supplies. One trip to Harbor Freight later, I now had a Harbor Freight spray gun with regulator (the $20 purple one that a bunch of people have), an inline filter to keep the air clean, a mask, paint cups and filters, and stirring sticks.
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| The sprayer came with a regulator to control the pressure at the gun – super important for a good finish. |
I also needed a rack or two on which to spray the parts, so I got some poultry wire from Home Depot and used some spare 2x4s lying around the garage to build a couple of 2'x5' paint racks that look quite similar to the tops of the EAA workbenches I built. The nice thing about these racks is that the parts can be sprayed and then left on the racks to dry so there's no need to touch the parts until after the primer is cured.
To make sure everything was working properly, I tested the Harbor Freight gun with some water.
I played with the fluid, air, and nozzle settings until I was happy with the amount being sprayed and the spray pattern, then I filled it with some primer and tested it out for real on some scrap aluminum pieces. The AKZO base and curing solution were super easy to measure 1:1 and mix, and the final coat of primer on the parts was strong and looked great. Satisfied, I put away the gun and eagerly waited a couple of days for my first real priming session.
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| The test parts after scuffing, rinsing, and wiping with acetone. |
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| One finished test skin. I can't imagine a better finish than this! |
