Here's something I've really been wanting to do for a while now, test my idea for finishing the plane! As mentioned previously, the plan is to fiberglass & epoxy the plane and leave it mostly clear/natural. I'm using a very lightweight fiberglass for this, which will hopefully limit the amount of epoxy needed. The test is being done on an extra wing I got with the Extra 300s kits. Actually, I got two extra wings, both left sides, and one of them was in such horrible shape I just threw it out. This one was kept to perform tests on.
Step one is to cut the 'glass to the approximate size needed. This is a leftover piece that'll do half the wing, good enough for me!
The epoxy being used is Z-poxy finishing resin, which I'm thinning with denatured alcohol so it is easier to apply. The mix stats off 50:50 resin to hardener, and then I thin that by about 50% with the denatured alcohol. So the final ratio is 1/3 : 1/3 : 1/3. The denatured alcohol gets mixed in after the resin and hardener are completely mixed.
With this stuff, a little goes a LONG way! I poured it onto the middle of the wing and then worked from the center out with a brush. After it's started I switch to an old playing card as my squeegee and keep working it farther and farther from center. Excess material is scooped up and moved to thin areas. You really don't want ANY excess material, and the goal is to get as much wetness out as possible. Any excess is removed, and I run the 'glass and epoxy just past the edges. I may try the other half of the wing with a little stain on the wood first, although I'm thinking that would be hard to apply evenly and the wetness could cause other problems - something I need to look into...
Note: I did this first test without adding any extra balsa filler to the wing panel. It was only sanded smooth and the extra balsa dust was removed. Assuming I do this to the entire airframe it'll all be covered with balsa filler and sanded just to make sure any small dings/dents/scrapes/seams are filled and smooth.
For anybody wondering what that black line is across the wing, is the hold-down strap on my "Wing Station", a handy device I got from a vendor at Flite Fest 2016. It'll hold wings, fuselages, etc pretty securely so you can work on the part easily. In my case it's perfect for only 'glassing 1/2 a wing!
Here's their owner's manual, it's worth checking them out online if you do a lot of balsa work. Covering a big wing becomes much easier when it's held securely.