Old Fuel

[Bill Smith]

Last week I flew my Cardinal in a contest in Chicago. I dug out an old (3 yrs) unopened bottle of fuel, tried it out and it worked great. After the contest I cleaned the plane off and brought it home, now a week later I look it over and the paint is blistering everyplace the fuel touched it. It looks like I sprayed it with paint stripper. I'm guessing the caster has gone bad but there is no bad smell. Anyone else ever had this problem.
Yea, I know I should have thrown it out long age but I have been unemployed and this stuff is not cheap.

[Tim Wescott]

It wasn't really high nitro, was it?  Did it just ruin the parts where the raw fuel touched, or where the exhaust went?

[Brett Buck]

Last week I flew my Cardinal in a contest in Chicago. I dug out an old (3 yrs) unopened bottle of fuel, tried it out and it worked great. After the contest I cleaned the plane off and brought it home, now a week later I look it over and the paint is blistering everyplace the fuel touched it. It looks like I sprayed it with paint stripper. I'm guessing the caster has gone bad but there is no bad smell. Anyone else ever had this problem.
Yea, I know I should have thrown it out long age but I have been unemployed and this stuff is not cheap.

    I have never seen fuel go bad if it was stored properly, and I certainly haven't seen anything like you describe. Very strange.

    Brett

[Mike Keville]

Which brand of dope is on your model?

[Randy Powell]

Well, there's no fuel like an old fuel.

[Randy Cuberly]

Which brand of dope is on your model?

Hey Mike...Ya think it's Brodak Dope.  I remember you and I both having similar fun with that about 10 or more years ago.

Randy Cuberly

[Mike Keville]

Hey Mike...Ya think it's Brodak Dope.  I remember you and I both having similar fun with that about 10 or more years ago.

Randy Cuberly

============================================================

More like EIGHT years, Randy - but you're on the right track there!   

[James_Mynes]

I'm currently using up fuel that I bought about 20 years ago. It was stored in a northern basement, cool, dark, but not always dry. Sig fuel, in the plastic jugs. I've burned 5 gallons so far, with 5 more gallons to go. Engines run fine, and I haven't had any paint problems with an old Sig doped plane or newer doped finishes.
I would suspect paint trouble, not fuel trouble.

[john e. holliday]

I my self am using up fuel sport flying that I have had for over 15 years.   So far no problems on any of my finishes.  You don't say what brand of fuel.

[Dan McEntee]

  The type of paint isn't mentioned either. I would suspect the paint over the fuel. Either the clear if it was clear coated or the base coats.
  Type at you later,
   Dan McEntee

[Steve Helmick]

It's not the fuel!  Steve

[Bill Smith]

rustolium paint, 4years old, only blistered from exhaust residue  
Sig 10% nitro 20% castor

[Dave_Trible]

I can only wonder if the dope was something left over from the old days or nitrate was used for a clear top coat.  I remember as a kid needing to put "fuel proofer" over Testors dope.  Once butyrate dope came on I used it from the wood up to keep from getting a handful of dope goo when I pick up the airplane.  Nitrate would be like that.

Dave

[John Stiles]

Well, there's no fuel like an old fuel.

I laughed out loud! 

[Dan McEntee]

rustolium paint, 4years old, only blistered from exhaust residue  
Sig 10% nitro 20% castor

   Not all Rustoeum paint is fuel resistant. I hesitate to call it fuel proof. I have used it in the paste with "Brickhaus" finishing methods with varying success. Since it was only on the exhaust side,you would think it was just the oil having the effect. If you had a tank vent leaking and spraying raw fuel in the prop wash or a rich condition where raw fuel was coming out with the exhaust, it could still be raw fuel cause the problem. In thinking about it, I'm betting on raw fuel leaking somewhere and being blown over the model by prop wash. The blisters being on the exhaust side just a matter of circumstance.
  I hope you get it figured out,
   Dan McEntee

[FLOYD CARTER]

Raw fuel will attack almost everything except epoxy.  You must be careful  while filling your tank.

F.C.

[John Stiles]

Raw fuel will attack almost everything except epoxy.  You must be careful  while filling your tank.

F.C.

Yep, and I've noticed when you use an electric starter motor, and/or flood-start engines, a lot of raw fuel blows out and back onto the plane.

[James_Mynes]

Raw fuel will attack almost everything except epoxy.  You must be careful  while filling your tank.

F.C.

Or you can use Monokote and not worry about it.

[john e. holliday]

It has to  be the exhaust it self.   It does get hot if there is not enough clearance.

[Tim Wescott]

Raw fuel will attack almost everything except epoxy.  You must be careful  while filling your tank.

I left a drop of 25% nitro fuel on some Rustoleum Gloss Protective Enamel for about an hour -- it left no sign on the paint when I wiped it off.

rustolium paint, 4years old, only blistered from exhaust residue 
Sig 10% nitro 20% castor

Not all Rustoleum paints are equal -- the "Gloss Protective Enamel" is what I've used without problems, and is what is reputed to be the stuff to use.  But I've had problems with the "Painter's Touch" black, and the Gloss Protective Enamel metallics.

Was it right next to the exhaust, or everywhere?  Do you recall the exact brand name of the paint?

[Bill Smith]

It's only blistered on the outboard side (down the full length) and only where the exhaust hit it.
I finally got some time yesterday and put a drop of fuel on the same side but above the wing where the exhaust had not touched it, Smeared it out and waited.  Two hours later the paint blistered up and this is protective enamel (white rattle can) .
And I checked and found no fuel leak from the uniflow tank.
The glue holding monocote on the wing is also letting go.
Probably will never figure this one out but now i can use this fuel to strip the plane for refinishing.  
Oh, it also made my skin itch where I touched it to smear it on.

[billbyles]

Raw fuel will attack almost everything except epoxy.  <snip>

F.C.

"Raw fuel will attack almost everything except epoxy."

Or two-part catalyzed polyurethane.