Fuel Quality and Fiberglass tanks

[nomadpete]

I recently had a problem with fuel leaking from holes in my fiberglass fuel tanks. It transpired that there were small holes developing in them. Close examination of the inside of the tanks revealed some soft spots of about 3mm diameter, as well as the pinholes that went right through. The soft spots were dark in colour and this colour vanished when the fuel had evaporated. These tanks are over ten years old, but why did they leak? I have been using mogas, and it is possible that I had accidentally got some fuel with e10 in it. I go out of my way to avoid that stuff but maybe some servo operator just did not tell me the truth.

 

The problem is this: How can we be sure that the fuel companies won't put some additive into their fuel which will cause a chemical problem with our fuel tanks or fuel system?

 

Note that even so called fuel resistant epoxy may not actually be fuel PROOF!

 

Check out this web article. Allow that it mostly refers to polyester fiberglass, but note that they did some tests on specifically ethanol resistant epoxy and it did not look good.

 

BoatUS.com - Seaworthy Magazine

 

Does any body know if there has been any objective research done on fuel effects on GRP?

 

PeterT

 

 

[icebob]

Hi Peter,

 

I got caught the same way and no the service station owner did not notify anyone of the added Ethenol, plus i suspect something else was added, it left a gray putty like deposit in the tank that totally blocked the filter, like the fuel had emolsified.

 

Avweb(USA) had some articles on this subject some time ago that was very comprehensive and there were representations to the FAA about disclosure violations by some fuel companies over there but do not know the outcome.

 

bob.

 

 

[Guest drizzt1978]

Hi Peter,I got caught the same way and no the service station owner did not notify anyone of the added Ethenol, plus i suspect something else was added, it left a gray putty like deposit in the tank that totally blocked the filter, like the fuel had emolsified.

Avweb(USA) had some articles on this subject some time ago that was very comprehensive and there were representations to the FAA about disclosure violations by some fuel companies over there but do not know the outcome.

 

bob.

I had grey putty type stuff, almost like condensed milk whitish gray from optimax in a car fuel filter many years ago.....caused all sorts off problems.....

 

 

[dazza 38]

I recently had a problem with fuel leaking from holes in my fiberglass fuel tanks. It transpired that there were small holes developing in them. Close examination of the inside of the tanks revealed some soft spots of about 3mm diameter, as well as the pinholes that went right through. The soft spots were dark in colour and this colour vanished when the fuel had evaporated. These tanks are over ten years old, but why did they leak? I have been using mogas, and it is possible that I had accidentally got some fuel with e10 in it. I go out of my way to avoid that stuff but maybe some servo operator just did not tell me the truth. The problem is this: How can we be sure that the fuel companies won't put some additive into their fuel which will cause a chemical problem with our fuel tanks or fuel system?

 

Note that even so called fuel resistant epoxy may not actually be fuel PROOF!

 

Check out this web article. Allow that it mostly refers to polyester fiberglass, but note that they did some tests on specifically ethanol resistant epoxy and it did not look good.

 

BoatUS.com - Seaworthy Magazine

 

Does any body know if there has been any objective research done on fuel effects on GRP?

 

PeterT

Hi peter, have you used the same brand of fuel, all the time or do you change brands from time to time.It might help narrow down the cause?

[Guest Maj Millard]

Got a call on the weekend from one of my bush mates with a 582 Xair. We put in new rings, did a major engine service and rebuilt the carbs including new floats, and all the latest little bits, less than six months ago.

 

Said he was flying along around the property when fuel started running out of one carb vent tubes.

 

I had him do the usual checks. The float needle valves were fine, and everything looked good and tight. He only found a few small strange black bits in the bowl of the offending carb. He uses Premium out of the tank as delivered to his property.

 

And then today I read the latest Rotax SB re: carb checking. Have you read it ?? interesting.

 

Are they saying the latest floats could be producing little black bits ?? or are they saying watch out what fuel you use....which we are aware of anyway.....................................

 

 

[Guest Qwerty]

I say we name fuel suppliers here. Bugger them and their public image and threats to sue. If some one knows of a crook fuel supplier I'd like to know BEFORE it goes in my tank and kills me.

 

I'm happy to get the ball rolling.

 

I have found that BP Premium and BP Ultimate, and Shell Premium (VPower I think its called) are clean and reliable.

 

I avoid (that is I will not buy fuel from) Liberty as I got a drum of etenol from one once.

 

Now try and sue me yu mongerels and see what sort of crap storm I can generate.

 

Have a nice day, Qwerty

 

 

[Guest ozzie]

Pete have a look at this site www.ultraflightradio.com and have a look thru the archives there have been a few episodes on fibreglass tanks and fuels. one was on last week. worth a listen

 

 

[dazza 38]

Hi querty, i was trying to a find a 'brand' but not naming them, because they as you know they might start litigation procedings. The reason i say this is because a few years ago went i was right into dirt bikes with HP engines, some premium fuels wasnt good for the engines. (although no effect on the fuel tank) I will just say their is a fuel, that wasnt the 'optimum' choice if you know what i mean? cheers. Caltex no problem. What about anyone else?

 

 

[robinsm]

Caltex premium no problem. I test the fuel I get every month or so with the water in the jar test. (I know I should do it a lot more frequently). No ethanol to date. You can also look at the interface of the petrol and water and some of the additives in the fuel will show up as a layer between the water and fuel or a discolouration in the interface.

 

Just my 0.2c

 

 

[Guest Maj Millard]

My friends' Xair by the way now has Alum tanks. He already had done the fiberglass tank thing, which as I remember clogged his fuel filter and stuck him on a road once.

 

Personally fuelwise, I like BP Ultimate with Caltex Vortex my second choice. I'll often mix avgas with either, in all ratios, and have had no problem with the 912 uls...........

 

 

[nomadpete]

Well, I cannot be sure which brand - I have used a couple over the time. So I don't know who to blame. Anyway, since it takes time (usually) before such things as leaks occur, it is impossible to nail it down to a particular tank of fuel. There is also the other problem of an immediate fuel blockage which could be caused by a fuel contaminant or incompatibility. I am concerned about our safety in the long term. Maybe it is simply best to go back to avgas and do the Rotax maintenance more often. I have heard reports of carby damage to small engines (mowers, motorcycles, etc) which has stopped them. So the risk is always there when you use mogas.

 

Thanks OZZIE for the link. Will check it out.

 

Was trying to stir up any info about the mogas problems, since the fuel giants are not likely to be much help!

 

PeterT