Craig Williams wrote: > Ok, I got the plane home last night. Today as I was sorting things I > picked up > the alum wing tanks. They felt very heavy. Just went out and put one on > a > bathroom scale and it came in at 10 lbs. Is that heavy.
10 pounds isn't terrible. However, I just built an eight gallon fiberglass tank using 1/4" Lastofoam, one layer of 9 ounce cloth plus one very wet layer of deck cloth on the inside, one layer of resin-starved 9 ounce on the outside, along with vinylester resin (which is resistant to both auto fuel and ethanol). It doesn't leak a drop even when totally full, and it weighs 5 pounds 3 ounces including integral "low fuel float switch", two baffles, and mounting bracketry (which is part of the tank). It's a rather flat wing tank, so its volume to surface area ratio is comparitively low. A more square tank would be somewhat lighter. I leak tested the bottom 9/10 with gasoline the night before I installed the top, and after that it was Hail Mary! I'm guessing I have about 12 hours of build time in this tank, 16 at the very most.. With vinylester in a hundred degree hangar, things have to happen in a big hurry! I know I've said if I had it to do again I'd build them out of aluminum, but after watching one be out of aluminum, and knowing how quickly I whipped this one up, I've changed my mind on that. See http://www.n56ml.com/900hour/100717039_tank.jpg for a picture right before I slid it into the wing. You can pick this picture apart if you want, but consider that vinylester under these conditions becomes completely unworkable after 6-8 minutes, and hard as a rock in fifteen. I hate the stuff, but it was designed to line ethanol-based auto fuel tanks at your local Zippy Mart... Mark Langford N56ML "at" hiwaay.net website at http://www.N56ML.com --------------------------------------------------------
