Priming attachment hardware?

Hi Guys

This is not a priming war question. So please don't start such an argument.

I've decided to prime every alu surface.
So this question goes to all the guys falling into the same "prime almost everything category":

Do you also prime your:
1) Piano hinges and pin? (how /why)
2) Powder coated brackets? (how / why)
3) Nutplates / platenuts? (how /why)

I am particularly interested in the:
(how) since the hardware either needs to move, swivel or has a thread; and
(why) since the hardware is either already protected or coated.

Thanks in advance,
Regards
Rudi

Rudi,

1. I primed and painted the hindges on my trimtab and flaps, but not he rod. If you paint the rod, it is probably not possible to insert it back into the hindges (note, that I used the single rod method on the flaps, and it is hard to insert it without oiling the rod).

2. For powder coated parts, get Van's powder coat touch-up paint. It is cheap, and it works great.

3. As far as I can tell, platenuts do not need to be primed. I have seen guys paint them, but I doubt that the paint will really adhere to them, but I could be wrong.

Hi thallock, thanx for your inputs.

Does anyone else have inputs w.r.t platenuts priming

No prime on the powder coated parts. Scuff and paint later. No prime on the hinges. It may interfere with proper fit. No prime on the plateneuts. I think they come with an oxide coating.
Steve

Probably a dumb question, but why prime parts that are not going to be painted?

It is my understanding that primers are designed to be a precoat for paint (to make the paint adhere better to metal), not to be a sealer by themselves. Paint is the "sealer" that prevents oxidation. Id think that an epoxy spray paint would be the better preservative...

Cobra,
I will not comment on why to prime parts that are not going to be painted, because Rudi indicated that he did not want to get into the highly volatile part of this subject. I will say, that there are many primers that are actually "primer sealers" which do not require a topcoat to provide protection. For example, the AFS primer is a "primer sealer", and most epoxy based primers are very good sealers.

Tracy.

Thanks Guys,

Steve:
1) You scuff the powder coated parts, then later prime them just before final coat painting?
2) Should you scuff the hinges though, for priming and final coat painting later?

thallock:
Did you ever end up painting final coat over the powder coated parts, or just used the touch up paint and leave as is?

Cobra:
Thallock is right...I should have said "I decided to Epoxy Prime/Seal every Alu surface"

I need a confirmation on the Platenuts still...

Thanx
Rudi

So far, the only thing that I have done the final coat on is the horizontal stabilizor. There's only a few powder coated parts, that are on the back of the HS. I did not do any prep on the powder coated parts, other than to touch them up with the touch-up paint. They did get primed and painted when I shot the rest of the HS, but that's just because I was too lazy to mask them. If the paint comes off, I'm not concerned because the powder coat is what is protecting them. Note, that all of the powder coated parts are either inside or not very visible, so I consider the powder coat to be the final finish.

A coating of some sort of film (paint) is preferred over bare metal. Most internal airplane parts are simply primed while the outside are topcoated for added protection from the elements and for appearance.
I primed the inners with AFS Primer Sealer.

Powder coated is as previously posted. I taped off mine so as not to get paint on them. the touch up from Vans is good.

Piano hinges are aluminum and the pin is steel. Paint the outside of the hinge and just lubricate the pin because steel will corrode aluminum and paint will not help in the hinged area. Periodically lubricate all piano hinges.

Most aircraft hardware has some kind of coating (cadmium, anodized, etc..) I'm sure the platenuts are also coated but not sure with what.

I'm no expert but I do teach aviation corrosion control class at a technical college.

Hope this helps,
Bruce Sacks
RV9 N659DB

Rudi,
On the powder coated parts, scuff and paint but they'll probably get covered with primer as part of the process, for example in the area of the horizontal stab and elevator hinge. If your shade of white paint matches the powder coat shade you could just mask those parts.
Steve

I've got confirmation from elsewhere, platenuts are corrosion treated and do not need to be coated unless you want to.