ORIGINAL: RhyanO

I just completed an UltraSport kit that was covered in ultracote.
I got a most excellent tip from "PiperChuck" to use a product called BalsaRite.
BalsaRite is a liquid that you brush on your un-covered airframe, it seals up the pores in the balsa fuel-proofing everything at the same time. I use 3 coats on the firewall, and fuel tank areas or anyother area that might be exposed to fuel.
The other great advantage to this product is that it reacts with the adhesive on the covering you will be using, making the covering stick much better to the wood than if there were no BalsaRite applied.

My recommendation is to use BalsaRite both as a fuel proofing agent and also to assist in the covering of your model.

Let us know how your model turns out.
Ryan