Alodine/Prime Before Drill/Dimple Question

I purchased a kit from a builder that couldn't continue. Quite a bit of alodining/priming has been done on a number of parts, mainly empennage ribs, spars, etc...

Most of the parts have not had their holes drilled to size or dimpled, yet they are alodined and primed. Obviously in drilling these parts, I'll leave the inside edges of the holes exposed & based on anecdotal evidence, I can expect the epoxy primer to chip when I dimple.

Seems to me that a rivet hole is precisely where corrosion might start & I need to retreat these areas after drilling/dimpling.

Thoughts?

(Charlie, I know I got your input - I'm looking for some sort of consensus (LOL, around here... right ))

I think it may depend on what type of primer. I dimpled parts primed with Akzo and had no probelm at all.

Also, I think a sqeezed rivit ought to make a pretty air-tight fit against the bare aluminum caused by final drilling.

Just one person's thoughts...

-Jim

He used Randolph EpiBond epoxy primer (2-part).

Yeah, I agree it will be tight, but water molecules are mighty small. I was wondering if capillary action might draw water into the joint. Perhaps I'm too worried because as Van is so fond of saying, it's just an airplane...

I guess it depends on how anal you want to be.
Even if you prime after deburr / dimple, you will have to be pretty particular to get primer down in every dimpled or drilled hole - think wing skins with hundreds of holes or the insided of folded skins. I also think that a set rivet will be a pretty good seal against the elements. I guess if you're really worried you might have to start dipping rivets in primer before you set them

Thomas

no

when you squeeze the rivet a great deal of force is exerted on the hole esp a dimpled hole, and probally causes micro cracks in the paint anyhow. prime A piece ot two befor dimpling and the paint chipped off the female side of the dimple,, i scotchbrited them and blew them off with high pressure air. then put a light coat on them. either way your good because its still alclad

Alright. I'm not going to worry about this. "Shut up and build..."

The only thing I worried with was the spar after I machine countersunk the rivet holes. I ran two strips of masking tape down the spar and sprayed the countersinks with a rattle can of Sherwin Williams self etch primer. If you go to my website (www.jimsairplanes.com) and go to the wing section there is a picture of the spar primed in these areas. Otherwise I would build and not worry about it. Hope this helps.