Epoxy primer inside spars

[Meyer]

All,

I am planning to epoxy primer the inside of the wing spars. How much does it take to do that?

I saw posts about someone using an airbrush gun on a long piece of PVC. Someone else just put a tennis ball in to cap each end, and sloshed primer around inside. I will do the tennis ball method I think. Any idea how much I should order? I was just going to order the epoxy primer from kitfox.

Thanks

Scott

[Esser]

I think about a quart per wing should do it if I remember correctly. You want extra so you know you covered everything. I, too, did the tennis ball method.

[jmodguy]

Eastwood.com sells a wand with a 360 degree spray head for spraying inside automotive panels. Check it out

[colospace]

Dustin, I used Corrosion-X inside my spars. Living in the low humidity of Colorado, I'm thinking that is sufficient although I will probably renew it at each condition inspection. I also soaked the inside of my lift struts with linseed oil early on.

[efwd]

Youll need to either spray or apply with a brush when it comes to the exterior surfaces. As for the slosh, I propped the quick built wing on a sawhorse. I put tennis balls into the spars at the floor. I poured the primer in at the end propped up on the sawhorse. quickly put the tennis balls into the ends and ran to the other end, picked it up and tilted back and forth. I used new, fuzzy tennis balls. Leaked pretty good. I think some have stopped the leaks by putting saran wrap over the ball first.

[colospace]

Left as delivered.

[FoxTrotter]

Dustin, I used Corrosion-X inside my spars. Living in the low humidity of Colorado, I'm thinking that is sufficient although I will probably renew it at each condition inspection. I also soaked the inside of my lift struts with linseed oil early on.

Colospace, how did you spray the inside of the spars? Did you simply use a spray can, spraying at one end and letting it drain to the other end, or did you use some kind of special long wand? How many ounces did it take to convincingly cover the entire internal length?
Thanks
Michael

[jiott]

I'm pretty sure I did all four spars with less than a pint, using tennis ball method. Pour in plenty to get a good slosh, then drain it out and reuse on the next spar.

[David47]

So just a bit of added info. Unless you remove the oxide layer on the inside (or outside) of the spars before you paint, the adhesion of the paint to the surface is debatable. Alumiprep or something similar should be used before you apply the primer, as this gets rid of the oxide layer and any oils or other contaminants from the extrusion process. I used alumiprep and then alodined the spar internals using the tennis ball method. The alodine has enough chromium in it to give corrosion protection against most nasties, such as salts etc. FWIW.

[Delta Whisky]

colospace - I'm liking the idea of using corrosion X or Boe shield - how did you apply it? Special spray rig? Tennis ball?