By most people's standards, I probably went wayyyyyyy....overboard on this.
Given the spar tube Alloy and its original heat & surface treatment (6061T6), Larry's comments certainly ring true....it's pretty darn resistant to corrosion in the first place. The materials and coatings, we and the factory, use on the planes is so far superior to what was used in the past with regard to sealing and corrosion resistance if we do nothing additional, it's still going to be better than planes of past, and many of them held up pretty good too considering.
If there is such a thing as "corrosionology"....study of corrosion....most of it is observed occurring not on an open surface or where there is good air exchange; but, where two pieces are in close contact and it gets moist and never dries out. A couple cases in point I have seen this happen on really, really old Piper tube and fabric planes.......between the fabric and aluminum leading edge formers, in/on the tubing on the bottom/rear of the fuselage.
For the wings, drag tubes and elevator push pull tube....I treated all with Alodine and Epoxy primer inside and out. The drag tubes and elevator push-pull tube were painted on the inside before assembly. Spar tubes were painted after the wings were complete. Epoxy used in sloshing the inside of the tubing was thinned severely; and, allowed to drain thoroughly with the tubes on end after sloshing the epoxy.
Have one attached photo of the wing which shows the epoxy paint on the spars with overlap onto the ribs to be sure everything was sealed well.
Probably overkill by most standards...but that's just my choice.
Sincerely,
Dave S
KF7 Trigear - Flying
912ULS, Warp Drive
St Paul, MN
Re: wing priming
Reply With Quote