aviator79's build

[aviator79]

I'm going to varnish my butt ribs, and was curious what application technique you guys used. Does spray application give substantially better results? The polyfiber manual specifies using a brush for the first coat and says that a spray gun may be used for subsequent coats. I'm just curious if it's worth setting up and cleaning my spray gun for two ribs.

For that matter, did you spray varnish the rest of the ribs? It seems it would make shorter work of the task, but you might get varnish all kinds of places you don't really need it.

[efwd]

I used a brush or foam brush to apply the varnish. As for over spray, I found a touch up spray gun to have a small spray pattern and I used it to do the primer on all the metal in the wing. I didn't find that there was all that much over spray for that so I bet if you spray the varnish you would be fine also.
Eddie

[mr bill]

I used Stits epoxy varnish, three parts varnish to 1 part thinner. It allowed the varnish to really penetrate, I brushed on 2 coats over all the wood in the plane.

[aviator79]

The manual calls for Hysol between the tank and the #1 and #3 rib capstrips. I have about 1/4 inch gap at the #1 rib, and 1/8" at the #3. Is the intent here to fill the gap with Hysol? That seems like a big gap to bridge. Would Superfil be more appropriate?

The materials, skills, and methods are all new to me, so please excuse me if I ask a bunch of noob questions.

[Esser]

I didn’t fill it all. The wooden spacers that are installed on the tank provide all the structural support. I believe this step is purely cosmetic

[efwd]

My gap was even bigger. I placed tape on the under side and filled it in with Hysol. I wonder if Super Fill will flake out from the gap over time? If I do it again I might lay in Hysol a little thinner and then put Super Fill on top so that the sanding down to skin level would be easier. Make an attempt at pushing the tank outboard as far as possible. Maybe even trim the flange off some. You will benefit from the added space on the inboard side so that your fuel fittings will clear the first rib. I was afraid to trim it off in fear of causing a leak in the flange but I know people have done it successfully. Had I knew the fuel fittings were such a close fit I would have done so.
Eddie

[jrevens]

... Make an attempt at pushing the tank outboard as far as possible. ... Had I knew the fuel fittings were such a close fit I would have done so.
Eddie

Good advice about positioning the tanks, Eddie. I filled my gaps on both sides with Hysol, thickened with flox. Used tape temporarily on the underside to help keep it from sagging also. I was able to smooth it out nicely, after a short amount of curing, so that no sanding was necessary.