Group,
After over 11 years of building on a  Glass Goose, I may be    finished. Not
finished in a good way, though.  I filled my wing tanks several months ago
and was delighted to fire up my Renesis.  Today, a month later, I noticed
the leading edge cap separating from the wing near the wing root and leaking
out of it.  With further investigation, I also discovered leaks on the
bottom of the opposite wing at the shear web.  The residue of the leaks is
yellow-tan in color and sticky.  My conclusion is that the alcohol in the
gas has had an adverse affect on the epoxy.  I'll call the epoxy maker on
Monday to get his words.  I read about the effects of alcohol on epoxy on
the internet several years ago but was assured that it wouldn't affect a
tank that was Jeffcoed.  Sealing the tank is the least of my concern.  What
makes me think the wings are now unreliable is that the fuel has wicked up
into many areas of the wings' integrity so, at this time, I don't think I
can trust them.  I offer this as a warning to those that can use it.  Do any
of you have any ideas or words that
 Sandy McNabb
 Renesis in a Glass Goose  (retired)


 Sandy,
 What kind of Epoxy did you use,  was it EZ Poxy? I am
 assuming you jeffcoed the tank based on what  you wrote am I correct?

 Does anyone know of any protection for  composite built aircraft
for the
 problem described here with alcohol  laden fuel or ethanol? FYI, fuel
 bladders is not a workable solution  for most composite airplanes.

 James Ealey

 I am  interested in your reasons on why fuel bladders is not a
 workable  solution for most composite airplanes. Are you speaking
 of the blue  foam Rutan method?

 Paul Lamar


 Yes, the Rutan  designs are what I was referring to with the blue
foam.
 With these  designs unless you get specially made bladders and you
are
 will to  eat the weight penalty you will
 definitely lose something that the  design offers in performance.

 James Ealey

 Auto  fuel is a 25% savings in fuel cost. I don't have a weight per
square
 foot yet on the McMaster neoprene nylon material but it can't be
much
 at only .022 inches thick. I'll order $5 worth and weigh it and  do
some
 fuel tests on it.

 Custom built was what I had  in mind for the fuel cells. One can
hammer
 ribs out of sheet steel  and use them to clamp and heat the joints.
 I suspect something like  250 F will do the job.

 It will take a bit of trial and error to  learn how.

 Paul Lamar


 James,

 I have a wet wing  with fuel in the whole leading edge rib
sections.  A
few
 holes are cut in the lower rib to let the fuel flow.  The building
plans
 call for sealing the surface area of all of those D sections plus the
holes.
 It is a daunting task and I doubt I can accomplish it with 100%
certainty.
 Worst get the outer skin is added later and those joints can't not be
 properly sealed.  Since I am exploring using high ethanol content
fuel,
I'll
 be hiring someone to weld thin 0.3mm Teflon bladders for me.  With
the
 absence of JeffCo coating the weight increase will be nelgible.  I
haven't
 figured out the connection method between them yet.  Probably need
some
 male/female tube connections welded on.  Bladders can be designed to
 collapse if desired.  Sandy, I wouldn't scrap the wings yet.
Chances are
 the ethanol is reacting with the epoxy surface or remaining wax.  I
don't
 know which type of resin you used but some of the vinyl-esters are
 specifically designed to hold solvents.  Chances are good you can
drain
the
 fuel heat up the wings to 25C and evaporate the remaining solvent
out of
 them.  If you are concerned with the integrity of the wings, make a
jig
and
 load test them with sand bags.  After passing that test you can
make a
plan
 to add bladders.  Water infiltrating into fuel tank depends a lot
on the
 tank material, vent air temp and humidity.  Naturally amphibs.
operate
in a
 humid environment.  Having the wing tanks feed a low sump tank is
also a
 good idea.  Pump pick-ups should be at least a half a gallon volume
above
 the bottom of this tank.


 Doug in Japan

 Those big tanks in the  ground at the gas station are now vinyl
ester. It
 seems that tanks made of  vinyl ester or lined or doubled up with
vinyl
ester
 would do fine. Or if you  have a TIG machine, or better yet, a
friend with
 a TIG machine, repair the  damage with whatever epoxy you built
with and
 make up some nice aluminum  tanks. Or, race car fuel cells come in
many
 interesting shapes and sizes and  the smaller ones are cheap
enough. You
can order
 the bladder without the  steel can. Check out ATL
 http://atlfuelcells.com/

   (http://atlfuelcells.com/)

 and


 http://www.buycheapr.com/us/result.jsp?ga=us3&q=racing+fuel+cells


 http://www.buycheapr.com/us/result.jsp?ga=us3&q=racing+fuel+cells


 Lynn E. Hanover


I think teflon is over kill.  I am not sure it is easy to weld.
Reliable
bonding is a problem.  Polyethelene is what most solvent bottles are
made
from if they are not glass.  It is a well behaved thermoplastic and
can be
welded.  Harbor Freight has soldering iron like tools for plastic
welding;
hot gas jet. McMaster has poly sheet in the catalog.

Murry I. Rozansky

Thanks for the harbor freight tip. I am going over there today
to get some polishing pads.

-------------------------------------------------------------------

I think Polyethelene  would be too stiff for retrofit through small
holes.

If there are 2 ribs in your tank it could be done by cutting two 6
by 12
holes
oval holes with three custom made bladders. The edge of the holes
are near
the
ribs so connections can be made to the next bladder. I suspect it
does not
take
long to make a custom bladder.

My 182 has a dozen access holes in the bottom skin :)

Sandy, Contact your local EAA chapter for help building the new wings.
All EAA people can learn from your experience.

Also get a bore scope and take a look inside. The harbor freight
unit is
marginal but home depot now sells them. I suspect it is better.

Paul Lamar

--
Group,

Sorry I haven't gotten back to y'all sooner. I've been on a three
day London
trip. To answer some questions, the epoxy I used is what the kit
supplier
sends me: CER 112-2 resin and hardener. I've talked with the
technical guy
at the supplier (Cass Polymers, Madison Heights, MI) and he has
confirmed
that ethanol is very detrimental to their epoxy. I suspected that from
conversations on the internet, however, I was assured that if I use
a JeffCo
lining in the tanks, there would be no issues. It's now obvious that
it's
not the case.

The airplane has wet wings with 3/8' foam covered with fiberglass.

When I first started this project I promised myself that I would not
ever
fly this airplane if there were any doubts about its safety. I now
have
doubts about the integrity of the wings. They may be just fine,
however,
even with borescoping and testing, I think I'll still have some doubts
because the spar is in the wet tanks and has been exposed to ethanol
for
over a month. If I was satisfied that the integrity is still in
tack, I'd
still have major challenges with correcting the ethanol issues with
the four
wing tanks. Actually, the four wing tanks are subdivided by the spar
in two
tanks, so blatters and/or sealing would certainly be a major
challenge. I'll
certainly make anybody a good deal on the project if they want to
give it a
try with the understanding that I think the airplane is quite
possibly not
safe and the wings should not be used. The project is complete with
the
exception of attaching the tail and building a cowling.

So, at this time, my first plan is to strip the airplane and donate
it to a
school or museum and part out the rest. I've got a 2005 Renesis with
5,000
miles on it that runs like a champ. The engine was rebuilt and
ported by
Bruce Turrentine. If I can't donate the airplane, then I'll try to
sell it
in one piece as much as possible (short of the wings which I will
probably
saw off) minus the avionics which I'll use in my next project. Oh
yes, I'll
be starting a new project soon. I'm kinda stubborn.

Did I miss any questions on this thread?

Got any ideas on how to donate it and to who?

Sandy McNabb
Renesis in a Glass Goose (retired)

IMHO parting it out is not a good option. You have years installing
the engine and cooling system unique to a Glass Goose. All that effort
would be wasted if somebody bought just the engine for installation
in some other type of aircraft. I have first hand experience with that
as I bought a flying RV4 with a rotary engine. I was mightily
impressed with all the thought, time and labor Mike Wills put
into the airplane. It would be a crime against humanity to part it
out :) It my opinion it was a stupendous bargain.

It would be a good buy for somebody else building a Glass Goose.
I would focus on selling it to that community if not the rotary
community..

Also I would not saw off the wings just yet. Further inspection
with ultra sonic techniques may prove they are not as bad as you
think. I would find a structural engineer and get his opinion.

Paul Lamar



Sandy,

Mark Forse, who teaches a composite workshop for EAA says that Abaris
company is the premier place to take composite training...they have
courses for industry people.  Maybe you can consult with them and get
an opinion about what to do?

Gene Kahn