I have a friend who's got extensive experience with all things composite. He's been my advisor for this process and was nice enough to let me use some leftover resin and excess cloth. This was my first experience with Polyester resin. It's not nearly as user-friendly as the West System epoxy I've used up to this point. The mix ratio was 1.5% catalyst to the resin. 1.5% is not very much! I used a gram scale for the mixing. As an aside, I found this little gram scale at Harbor Freight for about $13. Works just fine!

I set up two 8-foot banquet tables as my cutting surface. Since I don't want to ruin the tables with scratches and excess dirt, I covered them with moving blankets and then a very thin plastic drop cloth.

The fiberglass cloth is the old Rutan 8oz. stuff that I understand Burt Rutan specified for his Long-EZ line of aircraft. I don't really know anything about this, it's just what my friend told me. I really appreciated having the cloth. He says he's got a bunch of rolls of the stuff just sitting around. Good friend to have!

I made paper patterns of the various sides of my fuel tank plug. I then cut enough cloth to cover the tank with 4 layers of the 8oz. cloth.

Note the long 3" strips laying at the upper left part of this photograph. These were cut at a 45 degree angle (on the bias) of the fiberglass cloth and will be placed on the rounded edges of the plug. Cutting the fabric on the bias allows the fabric to bend/stretch more easily around the corners.

These electric scissors are quickly becoming one of my favorite tools around the shop. I monitor a bargain hunter website (www.buy.com) and these came up as available from Lowes for $4.99. I placed a web order for 2 units and picked them up the next day at the local store. I figured if they didn't work, I'd return the second unit unopened and only be out 5 bucks.

There's no way I'll be returning either of these! I can't tell you how much easier cutting fiberglass cloth is when using these sheers. Highly recommended.

Here's the plug after receiving 4 layers of 8oz. cloth. This is by far the most challenging fiberglass work I've done to date. The Polyester resin really kicked off quickly. I had to make very small batches and work quickly to get it spread out. The good news is that I could lay up the top of the tank in the morning and go to lunch. After lunch it would be hard enough to flip over and do the bottom part of the tank. Even so, it took me a couple of days to finish applying the cloth and resin.

I didn't take any pictures of the sanding process, but believe me, there was a ton of sanding required before it reached this stage. I mostly used a 17" pneumatic board sander--it's what a body shop would use along long straight panels like doors and fenders to make sure there are no waves in the body surface. In any case, about a day's worth of sanding with the board sander and 40 grit and my DA sander with 80 grit brought the plug to the point where I slathered Bondo on and then sanded some more.

In this picture, the Bondo is the pink stuff. The blue stuff is FeatherFil. FeatherFil is a lighter weight product sold by Aircraft Spruce. It works best to fill pinholes. It's about 5x as expensive as Bondo so it's not really practical to use for the initial filling process where a ton of filler was consumed.