A few weeks ago coming across Wadmalaw Sound I had issues with my fuel quick connect coupling clogging up with a gummy substance shutting the fuel off coming out of my ($800) custom made fiberglass tank for my old classic Whaler. Chris “V” advised me that it might be the ethanol gas softening up the resin on the inside of the tank. So, I pull the tank and take it to a tank cleaning service and have it steamed - the tank guy tells me that it looks like the resin on the fiberglass was about gone inside the tank and it probably wasn’t safe anymore because eventually when all the resin had disolved there wouldn’t be anything left but the woven roven fabric and it would leak like a sieve. So, we cut the tank in half just to see what what we had. As Chris indicated the resin on the woven roven had all but disolved inside of the tank. Even after steaming and drying it was still sticky to the touch and could be scrapped off with your fingernail.
If your still running a fiberglass tank in your boat it’s probably a good idea to pull it and take a look inside. I think I’ll drop a small piece of my tank off at Charleston Marine so anybody interested could stop by and take a look at what ethanol fuel does to the inside of a fiberglass tank.
Mike Austin
“HATTERASER”
Ouch! I thought the newer resins used for fuel tanks were ethanol resistant. How old is your fuel cell? They’ve been aware of additive problems with fiberglass for a long time.
dealt with a whaler in the early 90’s & fiberglass tanks & advised the guy to get rid of the glass tank then. He had carb issues caused by the tank.
21 Contender
Mike,
Thanks for the post. I bought an 05 Yellowfin knowing about the issues of fiberglass tanks and ethanol. The previous owner claimed to use nonethanol fuel. I planned to trailer it everywhere and would eventually need to use the ethanol fuel. Initial word was the coating inside the tank was the only affected item. I didn’t buy into that and saved some coin to drop in aluminum tanks. For a very reasonable price Yellowfin installed two new aluminum 1/4" tanks of slightly lesser capacity. The coating from the fiberglass tanks had begun to flake off. I would not take the chance of going offshore on the claims of a gas station selling nonethanol fuel. The pick up tubes get clogged, the pump bulbs get clogged and the fittings into the racors get clogged. Came in one day at just barely up on plane. $$ well spent!
if the gas dissolves the fiberglass I doubt a filter would take it out, since it would be “in solution” kinda like oil mixesd in gas is not taken out by a filter.
seems the industry needs a tank build standard, this tank biult to spec xyz, which shows resistance to ethanol.
A manina managr is sc told me many primb bulbs have ethanol weak parts.
04 Carolina Skiff, 90 Yammy 2S with plastic “smoke” colored tank. Ethanol did the same to my tank and clogged up the carbs, twice. New tank, filters carbs cleaned, Ok now. Not just fiberglass.
Carolina Skiff Doug
1980DLX Carolina Skiff
Mike,
The original Pate tank on my '89 Newport basicaly desintegrated last year. A buddy gave me a red plastic one that works great. Fits pretty well under the seat. Ethanol sucks…
Interesting. Back in 1980 I took a Pate Plastic (fiberglass) tank to General Engineering Laboratories in Charleston for analysis and asked them to determine the affect gasoline had on the resin, and the affect ethanol had on the resin. They confirmed my suspicion. Gasoline dissolved the resin, but ethanol dissolved it a lot faster. Back in those days I’d noticed a lot of carburetor gumming and even internal engine gumming that looked like resin, and I suspected it was coming from the tanks. I worked at a Whaler dealership in those days and we’d installed a bunch of fiberglass tanks in those days. No one wanted to admit they were causing a problem and I was making plenty of money fixing the problems they were causing.
In the boating industry for over thirty years.
cs-doug
was your smole colored tank a boat/factory tank?
mercury says
How does ethanol affect my fiberglass fuel tank?
Fiberglass tanks manufactured prior to 1991 may not be compatible with gasoline containing ethanol. It has been reported that, in the presence of ethanol, some resins may be drawn out of fiberglass and carried into the engine where severe damage could occur. If an older fiberglass tank is used, check with the manufacturer to determine if gasoline with ethanol can be safely used.
sounds like there are later made (your boat is 2004?) “bad” tanks
bgf- My glass tank was purchased from Miami Tank Company but I think Pate actually made the tank. I understand they are now out of business so I searched around and found a 16 gallon Moeller plastic tank that would fit under my seat on my old Whaler “SuperSport”. I think I purchased that glass tank back in 1989 so I guess I got my money’s worth out of it. 
Kinda of scarey to imagine what might have happened if I had been sitting on top of that tank going 35 mph across Wadmalaw Sound and have that old tank disengrate under the seat!
Mike Austin
“HATTERASER”
quote:
Originally posted by edwardh1cs-doug
was your smole colored tank a boat/factory tank?mercury says
How does ethanol affect my fiberglass fuel tank?Fiberglass tanks manufactured prior to 1991 may not be compatible with gasoline containing ethanol. It has been reported that, in the presence of ethanol, some resins may be drawn out of fiberglass and carried into the engine where severe damage could occur. If an older fiberglass tank is used, check with the manufacturer to determine if gasoline with ethanol can be safely used.
sounds like there are later made (your boat is 2004?) “bad” tanks
Mine is a 2004 Carolina Skiff with the factory 27 gal tank, sorta translucent plastic. I called Carolina Skiff and they played “pass the buck” and blamed it on Tempo company saying when the tanks were made, they weren’t worried about ethanol. I was in Morehead City on vacation when 1 cyl quit and the mechanic said they had seen several with this problem caused by the gas tank. I had the carbs cleaned earlier in the spring and they gummed up again. Bought another tank, filters, carbs cleaned and so far so good.
Carolina Skiff Doug
1980DLX Carolina Skiff
so much for mercury saying tanks made after 1991 are OK
Mine is a 19 gallon, Mike. I believe it is a Moeller also
My mistake, mine is and was a Moeller. The new ones are opaque.
Carolina Skiff Doug
1980DLX Carolina Skiff