Epoxy primer inside spars

[Floog]

Here's another strong statement from someone qualified only in offering an unsolicited opinion: The spars will last a lifetime without any additional protection inside or outside, ocean environment or whatever. I guarantee it!

[ken nougaret]

With this and your previous post, i have to ask, is this an inside joke that I am not aware of?

[efwd]

Alcohol cleaned, whiped down with scotch brite ( no circumferential rubbing ), alcohol cleaned again then straight to spraying Primer as the previous post describes.

[Floog]

Priming the inside of the spars is a waste of time, money. Adds weight and makes a mess too.

[aviator79]

If anyone is qualified to say this, it's you. But you didn't have to completely submerge them just to make your point.

[efwd]

Wow, quite a statement. I notice the "inside" of the spar is a waste but no mention of the outside. Living around the ocean, I wouldn't want to see what the inside or the outside of the spar would look like a few years from now if it weren't primed.

[SSFoxBuilder]

Has anybody considered CorrosionX or Boeshield T-9 as a spar corrosion preventative? I was planning on this at some point.

Both are usually applied as a mist and will "set up" a nice protective coating, probably more than sufficient for most Kitfox users...

[jiott]

I primed the inside, and outside too, of my spars because I figured someday I may want to put floats on it. Kitfox factory recommended priming the inside for float application, especially near salt water.

[Dave S]

I would promote the idea that doing something (paint, alodine, corrosion proofing/sealer), with the inside of the spars (as well as the outside like where many builders epoxy prime them) is important for long term service given that the most susceptible part of the assembly is precisely where little can be done with it inspection or repair wise. Where the insert contacts the inside of the spar tube is the most likely place for corrosion to start. I regard corrosion prevention/corrosion proofing to be critical in the long run - if a plane will be around for many years. Corrosion in lap areas in old aluminum airplanes is not unheard of - usually the little raised "donuts" around a rivet holding aluminum skin to an aluminum rib, or spar capstrips, or skin overlaps or similar lap areas is where it ends up.

Corrosion will eventually turn all aluminum into bauxite, from whence it came - some things speed up the process like electrolytes & moisture. Some things retard the process like sealing the surface to keep oxygen, moisture and electrolytes away from the surface (at least till it gets a scratch).

[FoxTrotter]

Are you guys doing this spar prep on quick-build wings (which is what I have)? Not clear to me how you're "holding the spar over your head and sloshing" with an assembled quick-build wing, nor how you're treating the exterior of the spars with all the ribs etc already in place.
Thanks - Michael