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