Anyone have pictures of unprimed internal surfaces?

[Polar]

I just spent the last two days prepping and priming all the internal surfaces on my empennage kit. Somewhere during all the scrubbing and rinsing and spraying I was thinking about the prime / don't prime debate. I've heard convincing arguments on both sides by people whose opinion I value, but I have yet to come across anyone who offers proof that priming isn't necessary. As in, I've never seen a picture of the inside surfaces of a vans aircraft with 'X' amount of hours. A control, if you will.

[rapid_ascent]

I've primed all of the internal surfaces. I started with water based primer and moved to Akzo after the tail kit. It is a lot of work with the prep but I think it's worth it. I'm not sure I'll ever build another after this one so I want it to last.

[LettersFromFlyoverCountry]

I do. The aft fuselage skins are mostly unprimed for me. They look the same as they did when I riveted them on 10 years go. Well,a little dustier, perhaps.

[Polar]

Originally Posted by rapid_ascent

I'm not sure I'll ever build another after this one so I want it to last.

And I'm doing the same thing, but is there any evidence that they don't last if you don't prime? You would think if primer actually did make an airplane last so much longer there would be tons of anecdotal evidence of corrosion issues on unprimed alclad parts. Maybe there is. Is there??

[Polar]

Originally Posted by LettersFromFlyoverCountry

I do. The aft fuselage skins are mostly unprimed for me. They look the same as they did when I riveted them on 10 years go. Well,a little dustier, perhaps.

Did you prime the ribs and whatnot, and just leave the skins bare?

[mturnerb]

No photos, but my 41 year old Bonanza has mostly unprimed internals and is doing fine. It's had some corrosion removal over the years but all those have been on external painted surfaces, especially where skin overlaps and where there is a lot of "splash" form the landing gear. It has spent most of its life in Florida.

That said, I'm priming all the internal parts (ribs, etc) and the parts of skin surfaces that they touch on the RV-14A I'm building (not priming the entire skins, just where metal is touching metal). I use a soldering iron to remove the plastic on the inside (same as on outside) along the rivet lines and remove after priming. Reasonable amount of weight, seems prudent living near the coast and doesn't take an inordinate amount of time. My approach to is scuff, clean and use self-etching rattle can primer.

[LettersFromFlyoverCountry]

Originally Posted by Polar

Did you prime the ribs and whatnot, and just leave the skins bare?

Right. I primed the ribs and bulkheads. And the wing interior skins are primed. But not the interior skin of the fuselage.

Didn't see any real reason to and I wanted to save weight.

[Sam Buchanan]

Originally Posted by Polar

I just spent the last two days prepping and priming all the internal surfaces on my empennage kit. Somewhere during all the scrubbing and rinsing and spraying I was thinking about the prime / don't prime debate. I've heard convincing arguments on both sides by people whose opinion I value, but I have yet to come across anyone who offers proof that priming isn't necessary. As in, I've never seen a picture of the inside surfaces of a vans aircraft with 'X' amount of hours. A control, if you will.

Sorry, no recent photo, but the unprimed interior skins of my RV-6 are as pristine as they were when the plane was constructed in 1997. The plane has always been hangared.

[Tbutler]

Sam, did you prime where ribs and skins touch? Like the above photo? Did you prime anything?? I have not so far, only sprayed rattle can primer on the few parts that the plans specifically call for, like the tank attach brackets, doubler plates, etc. Hoping this will work out fine in the end. I've read your blog and views on priming and feel the same. My goal is to fly and travel in the airplane, not still be building it. Nothing lasts forever....

-Travis

[brad walton]

There are a lot of production aircraft out there with unprimed interior skins and structure. So RV's with unprimed interiors will probably last your lifetime. Primed, they will last your children's lifetimes, and maybe your grandchildren. I primed the interior in the hope of building the best plane I could build.