Once we had applied 2 layers of cloth, a layer of foam, and 2 more layers of cloth, we applied peel-ply and then the bleeder cloth. This bleeder cloth is the real deal--ordered from Aircraft Spruce.

We fabricated another big bag and put the part in the oven.

In the spirit of belt-and-suspenders, we applied 2 vacuum hoses this time... one at the front of the tank and one from the rear. We figured we might as well give ourselves every chance of pulling a good vacuum.

You can see the outline from the honeycomb and the foam core. It's a pretty good vacuum.

We also re-did the lower (lid) portion of the two-piece tank. This is the foam core. You can see the stainless block with pipe threads to accept the finger strainer and fuel pickup. It's sandwiched between 2 blocks of phenolic. We just wanted to make sure the stainless wouldn't spin under the glass when I torque down on the fuel pickup.

I joined the two halves of the new composite tank just for trial fitting purposes. You can see the phenolic blocks on the upper portion of the tank. From left to right, they are mounting points for (1) my fuel level sender; (2) an input line from my aux. tank; and (3) the vent line port. There will be a tube running inside the tank from where the phenolic block is to the high point of the tank.

Also of note is the similarity in size and shape compared to the original aluminum tank. I thought I'd be able to improve on the capacity by making it bigger, but this is really the largest tank that would fit. It remains to be seen exactly how much fuel it will hold, but I'm hoping for around 15 gallons.

 

Now that the fuel tank itself is well on its way, it was time to start thinking about fabricating and installing the piece of skin that will cover the fuel tank and span the distance between the instrument panel and the firewall.

I can't remember right now, but I think this is .032". I went to a friend's shop and used his roller to get the skin to the approximate shape. I wasn't convinced that just screwing down a flat piece was a good plan. It was a bit of a challenge to form this piece because it's not just rolled, it's tapered from one end to the other. To add to the challenge, I had never used a roller before this.