SonexBuilders.net

I'm building the Sonex B tail kit and wondering what to use for primer for overlapping parts? Thanks again!
Alan K
Rye, NY

Alan,
Are you going to base out of HPN? Is that considered coastal or inland with respect to salt air? Are you going to tie out or be in a hangar?

I would skip it if you could - it is weight/time and weight is the enemy. Our 6061 airframes are pretty corrosion resistant if the conditions are not hostile. But I have used SEM self etching primer here and there. That is an option and not too hard to do, and if you just do a light squirt on the faying surfaces it should not be too much weight.

Nearly no primer on my airplane, except on a few 7075 parts I made. But I live in the midwest, in a heated hangar, and run a dehumidifier in the summer. If you have an aerovee the belly will never corrode.

Bryan Cotton wrote: If you have an aerovee the belly will never corrode.

Ain't that the truth!

Thank you, Bryan and Greg.
To answer your question, HPN is for the super-wealthy. When I was instructing for Panorama, with my 'employee discount,' the takedown for my 150 was $290 in 2005! I could probably buy a new Onex kit every year for what they charge for hangars!
I will likely be basing the Sonex at 44N - SKY ACRES, about 8 miles east of KPOU where the takedown is only $70. Doubt if my finances will allow me to rent hangar space there.
So I'll look for SEM self etching primer to apply here and there (I didn't see many places they wanted it, in the plans or the video.

THANKS AGAIN FOR YOUR REPLIES!!
Alan K, Rye, NY
516 557-1200

Everybody that makes rattle-cans has a self etch primer. NAPA (Martin Senour), Rustoleum. They are all the same in performance. I keep a can handy, but rarely use it. I'm a slob about it too, and do no surface prep.

My view is that where you're based, you only need it as an undercoat for single pack top coat, but Navy carrier practice (well, they would do extensive, expensive surface prep first...) would be to put it on both surfaces of any faying joint, say, a lap in the wing skins, or at the rib to skin joint.

It's not clear to me that a single pack self etch primer will live under a two pack top coat. Stits and all the car paint people make two pack primers that are impervious to urethanes and pyroclastic flows.

If you WANT to go down a rabbit hole, there is a whole sub-forum on the Vans Air Force bulletin board about primers. It's one of those Christian/Muslim, Mac/Windows, Ford/Chevy divisive schisms, and I'm not exactly kidding.

Looks like a Portuguese barbecue joint within walking distance of Sky Acres! Gotta be the place!

Interesting, KarmaRepair.
You caught me just as I was about to hop on my motorcycle to take a short ride ('cause it's a nice day here in Rye) to a Kemperle auto parts store that supposed to stock SEM self etching primer (rattle can- last time I used one of those was to spray-my YTL football helmet in the 60's!). I'll have to check out that Vans forum. I'm probably way over-thinking everything, I'm beginning to think. As far as whether it will live under a 2-pack top coat . . . frankly, by the time I finish this Sonex B, I'll probably leave it shiny aluminum with maybe some vinyl artwork & numbers. Getting in the air is my top priority, not winning awards.
I'm not aware of any BBQ join in walking distance of Sky Acres - there's a restaurant on the field though. Perhaps it depends on 'walking distance.' I think about a mile to the north there's a restaurant I've never been to.

Alan K
516 557-1200
Rye NY & 44N

There's a good video / or series called Metal Magic: Should You Bother Priming? from Kitplanes (free) on YouTube here:
https://www.kitplanes.com/metal-magic-s ... r-priming/