My opinion: old fibre-glass fuel tanks are a real hazard

[HighWing]

Wayne,
For me personally, I would remove the wing and with a friend rinse the tanks with Acetone until clear, then slosh with Kreem. I have had the exact same problem and did the deed. My new Model IV has original Kreemed tanks from 1992 with no issues - Yet!. Other opinions are sure to vary.

[Jwayneball@aol.com]

Wayne,
For me personally, I would remove the wing and with a friend rinse the tanks with Acetone until clear, then slosh with Kreem. I have had the exact same problem and did the deed. My new Model IV has original Kreemed tanks from 1992 with no issues - Yet!. Other opinions are sure to vary.

Thanks a lot for the advice. Makes sense. Does this product, Kreem, enable the use of gasoline containing ethanol?

[Av8r3400]

Personally, if it were my plane, I'd be putting in a new tank.

If it's "leaking like a sieve", I wouldn't trust any type of slosh compound to fix that.

If it is "leaking like a sieve", I also wouldn't trust the structural integrity of the tank any more. The fuel tanks are integral to the stability of the wing. The last think you want is the wing to fail on you in flight because the tank collapsed.



Just my opinion.

[HighWing]

Wayne,
Lots of controversy over the years regarding Kreem. My original tanks were factory Kreemed. About five years into the flying part and I began seeing some very small bubbles appearing under the Aerothane between the filler neck and the outboard edge of the tank in top. I finally shaved off one of the bubbles and it was a blister of fuel. This was on a week long camping flight with friends and we were on Avgas. I did as I mentioned and the problem stopped. I flew nine years on the first airplane with avgas only on the annual camping trips. My new Model IV has factory Kreemed tanks and as I said in the first post - one year and so far good.

There have been some Kreem failures, most notably having it separate from the tank surfaces in sheets resulting in clogged finger strainers. Some have attributed this to release agents, but the tanks are made up from female molds and any release agent would be on the outside of the tanks. My personal theory is that the resin used on the tanks is oxygen inhibited and the surface resin won't cure thoroughly and if it softens under the Kreem it can result in the Kreem sloughing off. The new OH resistant tanks have to be rinsed prior to use to remove any uncured resin in the thanks to prevent buggering up the carburetors - same issue, I believe.

Kreem claims Ethanol resistance, but it cautions about certain fiberglass resins and recommends a spot test. Like I mentioned, I am comfortable with it based on my personal experience and the guys I have flown with, but - and I am surprised others haven't commented yet - others are very leery of it.

[Jwayneball@aol.com]

Thanks for taking the time to respond. I wonder if there are alternative products that might work better. In any case, it appears that cleaning the tank well before application is critical to success. Thanks again for the advice.
Wayne

[Jwayneball@aol.com]

Personally, if it were my plane, I'd be putting in a new tank.

If it's "leaking like a sieve", I wouldn't trust any type of slosh compound to fix that.

If it is "leaking like a sieve", I also wouldn't trust the structural integrity.........


Just my opinion.

Thanks for the advice. I think you make a very good point. Once I get the tank out, I will be able to see just what the condition of the tank is.

[Dutch]

Wayne Was the plane ever flown? If not maybe the Quick drain valves were never installed. Seems like there was another post a couple of months ago that had the same issue. No drain valves and the whole wing filled up with gas.
Dutch

[Jwayneball@aol.com]

Not flown much, Dutch. I was told when I bought it with 7.5 hours on the Hobbs that no gasoline had been put in the wing tank. There is the standard drain that you use to check for water but when I tried to get some fuel out of it, nothing would come out. Gas did come out the wing drain hole which is near the root of the wing on the trailing edge. If there is any other drain access, I don't know where it would be. Can you tell me more about Quick drains?
Thanks for your help,
Wayne

[Dutch]

There is a small sump in the bottom of the wing tank.With a small threaded hole in the center it is covered up in the covering process. after paint you burn a hole through the fabric and install the quick drain valve. It is where you check for water contamination. The line coming out of the root of the tank near the rear spar is the fuel supply line to the system. Feel the bottom of the tank you should be able to feel a small bump it will usually have a re-enforcement patch installed over it.
Dutch

[n85ae]

This is in the category of, super duper highly unlikely, unless a total alignment
of all the planets in the solar system occurs on a Friday the 13th ... Leaks on
the other hand, That could happen.

Regards,
Jeff

If it is "leaking like a sieve", I also wouldn't trust the structural integrity of the tank any more. The fuel tanks are integral to the stability of the wing. The last think you want is the wing to fail on you in flight because the tank collapsed.