Don't forget the invaluable Dremel tool with a variety of attachments: cutoff wheels, sanding drums, etc. I hope you have one; they are very handy for the type of work you are doing with the wood ribs. I have used mine continually thru the whole project.

Gluing Hysol on top of varnish-not the best idea. Your joint strength will be only as good as the varnish adhesion to the wood. Varnish is a coating, not realy a glue like Hysol. Probably no big deal on rib stiffeners but I sure wouldn't do it on important things like wing ribs glued to spars.

Jim