Charlie and Tupper England wrote:

I need some info on repairing leaks in fiberglass fuel
tanks.I'm hoping for a non invasive procedure, something
like the metal tank guys do with low viscosity sealants
applied to the outside & a light vacuum applied to the tank
to pull sealant into the leak.

Have any of you 'glass airframe guys had any experience with
this?

If you can help, please email me offline at:

cengland@netdoor.com

Thanks,

Charlie England

I think that is of intense interest to all of us building

composite

airplanes.

Pin hole leaks in composite airplane fuel tanks appears to be a

very

common problem.

Paul Lamar

The tank sealant used on most "wet wing" metal planes is called Pro

Seal and

it adhears to fiberglass as well.  This stuff is resistant to auto

fuel with

alcohol and works great but is not "sloshable".   All of the

sloshing

compounds (both aircraft and automotive) I've tried have failed the

auto

fuel test.  The small amount that I ran down the seams in my tanks

(thank

heavens I didn't actually slosh it) peeled off after about a year

and lodged

in the gascolator screen.  BTW, this is one reason I like a coarse

filter

that can be inspected in the fuel system before the final fuel

filter.  You

can see trouble coming before it becomes an in-flight emergency.

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

Thanks to Tracy & all the others who responded. Now that I
know Proseal sticks to fiberglass, I'm going to try that
(with suction) first.

I'll post results when available.

Charlie England

BTW, Proseal is just a trade name for the generic Polysulfide which was
mentioned in other posts.  You will recognize it in use because when the two
parts are mixed it smells like a cross between cat crap and rotten eggs.
The low viscosity brush on variety should be ideal for fixing fiberglass
leaks.

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

 
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