The Murphy Builders Site

I plan to put my Rebel on floats one day and in preparation for that day, I was wondering if it makes sense to cover the entire insides, not just mating surfaces, of the Fin/Rud/Stab/Elev surfaces as well as the aft half of the fuselage.
I will be using the STITS EP-420/EP-430 Epoxy Primer to cover all mating surfaces and would like to use the same for the insides of the entire empannage and the fuselage...could the epoxy be sprayed or does it have to be brushed on?
I would sincerely appreciate your thoughts, experiences and words of wisdom.
Thanks.

I use the 420/430 primer with a $30 Harbor Freight HVLP spray gun and it works great, so does PPG ShopLine primer. Just be sure to mix the parts like it says on the can. It's really easy to get it too thin so be careful on the proportions. Set the gun for a light spray or misting just enough to cover the bare metal without putting on a glossy coat. Be sure to use ScotchBrite (green) and wipe down with MEK where you're going to spray and don't touch it with bare hands. As for the decision to spray all the surfaces, it depends mostly on the environment the plane will be in. I plan on putting my Rebel on floats too, so I sprayed the whole inside of the empennage. For the rest of the plane and since I'm going to be inland away from saltwater, I'm only going to spray the mating surfaces. But... if the plane will be based near the coast or ever flown around the ocean or off the ocean, I would spray all of it or at least coat the inside surfaces with Corrosion X. Too much primer will add some weight to the plane. A lot of builders I know don't use any primer on the inside and have never had a problem with corrosion, but we're in the Midwest with no exposure to salt or chemicals.

Lindall

Thanks, Lindall, for your suggestions.

The epoxy primer should be BRUSHED on between parts,
which are then assembled while WET !

If you spray, you lose TWO big advantages of the epoxy -
it fills any gaps between parts AND it bonds them together,
increasing strength of the joint.

Don't spray without a fresh air hood !!! You could end up
with your lungs glued together !!! :-(

I concur!