Primer Recommendations

[rkiefer2]

I recently bought an RV14A EMP Kit from another builder. Minimal work done, but some of it was primed on the inside with a greenish tint epoxy primer.

What primers do you recommend for inner facing parts for corrosion protection?


I see Vans reference some stuff from Sherwin Williams. Im hoping theres something decent in a spray can.



Roger

[brad walton]

Roger, this is referred to as the "Primer Wars" and is an ongoing debate here on VAF. DO a search. In my opinion, you need a good 2 part self etching primer. Spray cans don't adequately etch, again my opinion. I cleaned the surface with lacquer thinner, roughed with a maroon Scotch Brite pad and sprayed a 2 part primer containing acid to etch the surface and form a good bond.

[wirejock]

The primer issue can be overwhelming. Even surface prep is a a big deal.
There are a few commonly used rattle can primers.
SEM, NAPA 7220

[Robin8er]

I use sherwin williams aerospace. Its an aircraft specific epoxy primer. Nobody can really argue about using a name brand aircraft primer on an aircraft.

[aeroaddict]

There are two schools on priming; those who do and those who don't. There is no right or wrong.

MY OPINION; I use the SW primer that Vans uses, but only on the bare (non alcad) parts; extrusions.

Now I did prime the inside of the cockpit area as I plan to topcoat this with a paint of my choice.

There are numerous theories out there and here is mine. The vast majority of parts are alclad sheet stock. These sheets have an almost pure aluminum coating that sandwiches the alloy. I do not understand why some builders go to great links to scuff and almost remove this gorgeous pure aluminum coating for the sake of corrosion protection. Like I said, this is just how I choose to build my plane.

Now if I lived on the coast and had a float plane, I'd prime everything I could get to.

[YellowJacket RV9]

Think about your specific situation. Do you live or fly near salt water or in a humid climate? Do you plan on flying your plane for the next few decades, or want the most possible resale value, or do you want to be buried in the thing? Personally, I hopefully have many decades of flying ahead of me, and I live on the gulf coast of Florida, so I primed my interior; AKZO for the wings and EkoPrime for the fuse. I will also confess to some rattle-can primer usage for convenience sake. As of yet, nobody's fallen out of the sky for lack of primer, however.

Chris

[wjb]

Yes, primer wars. Now, after finishing the emp, wings, and fuse, I sure wish I lived in Arizona with 0% humidity and no need for primer for corrosion protection. It is a significant extra step in the build process and adds many hours. Alas, I live (and will fly) a few 100 yards from the Pacific, the world's biggest puddle and a great source of salt spray.

I went with the Stewart Systems EcoPrime, a water based primer. With average surface prep (degreasing with acetone, and AlumniPrep etch helped along with a maroon scotchbrite pad), I found that adhesion is excellent, and the process is devoid of nasty epoxy chemistry. I have nothing against the epoxy product; they are likely better than this. I'm doing my spraying at home in the garage/driveway. Don't want a superfund site ;-)

I found that the Stewart Systems primer with a Sherwin-William JetFlex WR topcoat (also water based) for the interior makes for a very durable finish.

The exterior, I plan, will be done at an appropriate shop with all the good but nasty chemistry in a proper paint room.

[Rdwrv4]

I have excellent luck with spray can primers but I etch the aluminum first with eagle 1 etching mag wheel cleanerI spray it on and go over it with scotch brite while wet rinse it with hot water or cold dry and paint right away. The process is quick and convient. I use different can primers rustoleum aluminum primer for white colors or grey one people like. It works great you can see the metal brighten as you clean it and it removes heavier corrosion too. Primers really stick. it is the same chemistry is aircraft aluminum prep but comes in a spray bottle and most auto part stores have it.

[AviatorJ]

I found AKZO and Prekote as a combo very effective and easy to work with. I did my entire Empennage with it. Now I'm going the quickbuild route and Vans uses that wash primer on the wings and fuselage so I'll leave it be.

Any little pieces I decide to prime moving forward I'm just going to Prekote etch the piece and then use self etching rattle cans stuff. That will be more of a precaution.

[Boomer506]

I'm on my second project and have become a big fan of sponge brushing Variprime 615S. Its a good two part primer and is also a self etching primer. The stuff I buy from local auto paint shop still shows chromate in the MSDS so I feel like I am getting the sacrificial anode thing going. I can mix a thimble full so besides saving time on not having to spray (because I sponge brush it on), I also save money on minimizing amount of product used. It also allows me to make pencil marks on primed skin and parts. I mix it very thin so it doesn't add much weight, and a little goes a long way. It's almost like a wash primer, and I put it on everything.