What brand of primer Builders used

My first post was

Starting to build RV 12 Kit # 120400
What are most of the builders using for Primer
Does not priming hurt the resale?


Still trying to find out what type of primer builders ars using

400 Kits sold 40 to 50 flying
350 + or - still building

Does anyone Know what most of the builders are using.

And about what % don't Prime.

Trying to make the Decesion ????

Thanks
Joe Dallas in Florida
www.joesrv12.com

Joe,

There is plenty of discussion and differing opinions on this, and many earlier threads. Do a search on "primer" and read previous threads, then come back here if you don't get enough information.

Congratulations on your choice of an RV-12.

John

Congrats on the 12!
My suggestion, if you primer it, paint it before you fly it. Primer loves to soak up oils and grease, finger prints and bugs, bird poop and people sweat.

Aluminum parts should be acid etched and alodined, then primered with Zinc Chromate. I know several people have used self etching epoxy primer, that stuff is pretty good but a bear to sand smoothly.. and will still flake if the surface is not prepped well.

Fiberglass parts should be primered with a high quality 2K automotive primer.. again you can use epoxy, but its tough to sand.

Prime and paint it with good stuff and it will last for a very long time.. stay away from rattle can paint if at all possible.

just my 2 cents

Have fun with the build!!

Method I Utilized

Not to start any primer wars but since the question was asked, I will share the hybrid system I used on my RV-12. Note that what I have used is largely for interior surfaces. I plan to have the exterior painted by an experienced aircraft painter.

For select mating surfaces where I had concerns about trapped moisture and for aluminum parts that were not Alclad, I used the Sherwin Williams P60 G2 wash primer than Van's uses on its QB kits. It is fast drying, sticks very well with minimal prep, and can even be brushed on smaller surfaces with a cheap foam brush. For larger parts, I used a spray gun. I did not use this for any parts that would later be topcoated or visible in the cockpit or on the exterior.

For the interior surfaces of the cockpit, I used ANAC (Azko Nobel) 10P4-2 Epoxy primer. Some refer to this as "Boeing Primer". It is actually used by several major aircraft manufacturers. While expensive, I absolutely love it. It sprays very easily, flows quite nicely, dries quickly, is extremely durable, and for parts where an absolutely perfect finish is not critical, can be topcoated without sanding as long as it had dried sufficiently but not completely hardened (the product literature provides all of the details on when it can be topcoated). I then topcoated the interior with Imron. The combination probably generates one of the most durable finishes possible (and I have used other systems including typical automotive primers and acrylic enamel). In my opinion, there is nothing in a rattle can that could come close either. My surface prep was merely scotchbrite to roughen the surface followed by a good cleaning with acetone. No messy acid etch or alodine. I know several professional aircraft paint shops also use the same process and restrict their alodine use to refinish jobs where there is some surface corrosion. I also primed the gear legs so that they would be protected where they contact the center section of the fuselage and so that they would be ready for later exterior painting.

Note- both the Imron and the epoxy are pretty nasty without appropriate respiratory protection. For the Imron, a fresh air system is best.

For the exterior, I will look for a shop that uses epoxy primer and urethane topcoat as well.

Jeff

What brand of primer builders used

Van's doesn't recommend priming for most of the construction of the RV-12, with exception of a few parts made from 6061 aluminum or steel. The weight of the paint takes away useful load. If you look at Van's personal -12, he left a good portion of the external surface unpainted.
The RV-12 plans show a list of primers that may be used, but are not "recommended" by Van's. Many are two part epoxies which can be a nuisance when trying to complete small assemblies. Most have to shipped from a distributor, adding cost.
Aerosols are handy painting small parts, however when priming flanges on ribs, for instance, I applied primer from a can with a foam brush. I only painted surfaces that were in contact with other surfaces and only one surface. I used Marhyde brand self etching primer. It comes in aerosol #5111 and in cans #5112 and has a light gray color. Colors may vary from batch to batch, so if that is a concern, order enough to finish the project.
Marhyde appeared to be easiest to use, but had to be purchased from a distributor which involved lead time and extra cost. I recently found an equivalent, SEM #39683 self etching primer at my local NAPA Auto store. It seems to be the same color and less costly. NAPA also sells their brand #7220which is a dark shade of gray. When it's covered who will know? Standard auto primers should be avoided as they are not self etching.
When using self etching products on Alclad, the surface should still be scuffed with Scotchbrite and cleaned with naptha based surface cleaner like NAPA 6384 which removes dirt, grease, wax and finger prints, but not previous primer. If you don't do this, your primer will soon peel off.

Why do you want to use primer?

There are lots of good primers on the market. A primer is not per se a means of adding corrosion protection,however. It's primary function is to provide a base for the top coats. If you are looking for protection, than a primer-sealer does a better job. I used the Stewart water based primer-sealer on my interior. It is easy to use, and less toxic. I've also used the Poly Fiber epoxy primer. The Poly Fiber is almost like a top coat. It is hard, and has a semi gloss finish.

Strictly speaking, primer is used under paint. This being the case, many primers are not particularly resistant to solvents or UV exposure. However, they are designed to stick to metal and provide some corrosion protection. Thus a true primer is exactly what you want on the exterior of the plane.

Regarding the inner surfaces, most are alclad and pretty resistant to corrosion in all but the harshest environments. Non clad parts will corrode though and should be protected. I personally shot AZKO on all the innards of my plane. It's not really a primer designed to accept paint, but rather a corrosion inhibitor dseigned for airframe guts. It's not designed to be out in the sun, but is extremely resistant to solvents. Sprays easy and dries quick.

On the resale question, I think it's fair to say that if a buyer was looking at two identical planes he might be more inclined to buy the one that's been primed, but I can't imagine it being a deal breaker. If I were building another metal plane I'd probably skip all the clad surfaces as it really does add quite a bit to the build time.

I use Cortec products for the interior for corrosion protection. They are less demanding when it comes to personal protection and cleanup and are easy to work with , while maintaining an excellent record on corrosion protection.
I scrub the Alclad with a maroon Scotch-Brite pad and VpCI-440. It gets just washed off with water. After drying it I apply a thin coat of VpCI-373 green, they also have a transparent version of the 373 which is significantly lighter in weight but then I find it hard to see if the coat is solid or if it was primed at all.