Fiberglass gas tank

[Geebert]

Something just occurred to me recently regarding old gas tanks and i thought id throw it out here for food for thought, or possibly an answer from someone with more information than i have been able to find.

Its pretty common knowledge at this point if you have gas engines, and a fiberglass tank, you have to replace the tank, if you ever run gas with ethanol in it, because ethanol will destroy the fiberglass.

All the new gas stations ive seen built around me, all have fiberglass storage tanks. Old gas stations that are required to replace their tanks, are replacing them with fiberglass. I haven't seen any use steel in my lifetime. (Im older than some, younger than others), I've tried to find out what resin is used in storage tanks, but can't find that specific info, and some of these tanks are rated for much higher percentages of ethanol, and even 100% ethanol.

If there is some fiberglass that can tolerate it, i think I'd rather have that then any other material, plus the ability to have a built in tank.
I wonder why the word got spread that ethanol eats fiberglass, instead of ethanol eats certain kinds of fiberglass.
Anyway, my boat already has an aluminum tank, so i guess I'll just plan on replacing it when it pin holes from corrosion

[Tony Meola]

Back in the day when all this ethanol business started, there were a couple of manufacturers that would make ethanol resistant glass fuel tanks.

Danny from High Tide had a contact that would make them. I believe these one offs got price prohibitive.

[Snipe]

I believe the resin used is vinyl ester pretty sure it is safe with ethanol. I think some of the original tanks were ok with ethanol mine was fine it didn’t break down but my Dads deteriorated and the resin ran through his engines making a real mess.

[Carl]

It is the resin that was dissolving from the fiberglass tanks…but it’s the resin that hold the glass fibers together.

The resin used in the early Bertram and Hatteras boats tanks was vulnerable. Somewhere they changed to a more ethanol compatible resin…

Today you can buy fiberglass tanks that are ethanol compatible. Price is up there…but what is cheap. and these should last a lifetime…just like the original fiberglass tanks said to last a lifetime, unless they don’t.

[Geebert]

Thanks for all the info, i had totally written off fiberglass tanks, but i guess I'll have to look into it again

[Tony Meola]

Give Danny at High Tide a call. If he is no longer handling them, he can probably point you to a person who can help you out.

[Geebert]

Give Danny at High Tide a call. If he is no longer handling them, he can probably point you to a person who can help you out.

Are they in North Carolina?
There's a high tide marine in the keys, but the website says NC.
Are they both the same guy?

[Ironworker]

He works out of Highlands, NC

[Rick Jester]

Always hesitant to post sometimes, but I decided to add my 2 cents. My fiberglass gasoline tank was in good shape but I didn't want to run it as is with the current fuel.

I cut 2 large holes in the top, sanded the inside, and coated the tank with Phenol Novolac Epoxy. I used clear epoxy but should have got it colored to make it easier to see any missed spots. I used a brush and roller to cover the inside. It was a relatively easy job and I am satisfied with the results.

I have yet to use the tank though.

[Carl]

Rick- I'm not sure why you would be hesitant...the info you share can help others make informed decisions.


When I had my issues, what you did was an option I had thought about. If my tank was in good condition, having no issues I think I would have gone that route of sealing the inside.
What stopped ME, at that time it was the thought the ethanol was digging deeper dissolving/attacking the resin below the surface. With that in mind I could be sealing the attacking agent between the new sealer and the outside... which would "possibly" allow the ethanol to continue compromising the tank wall.

So one hand I had less work, and less expensive to try and seal.

The other hand IF I was wrong I could have a bilge full of gasoline...or at least 172 gallons.


The "other other" thought was ethanol made the tank porous as it leached the resin out, which allowed impurities in. Whatever product I considered using required the surface be clean of contaminants. How does one do that, if the product did not seal and stick as the surface has crap in it. Steam, cleaners, grind...how deep how far does one go. The best worst case scenario is if the stuff lifted some allowing the dissolved funk back into the motors.


ANYWway that WAS my thinking. Had I opened tank and saw a perfectly fine gel coat or glass finish...I "think" I may have gone your direction over an aluminum tank with a limited lifetime depending...

Thanks for sharing,

Carl

[bob lico]

my boat is a 1973 version and was originally diesel (504" cummins ) very heavy engines . i then installed Yanmar 6cyd 250 hp i think STE version i had those about a week and i guy made me a offer i could not refuse at that time i took off the fuel level/fuel feed plate and drain every bit of fuel out of the tank and used a camera inspection device to see every inch of the tank .no deterioration and it was a 230 gallon tank so i guess i lucked out .i assemble it with the offshore race boat fuel level indicator that works on the same principal as a super switch for bilge pump.seriously i can tell within a few gallons the fuel level .

[Carl]

Bob,

With diesel in its present state does not deteriorate the older fiberglass tanks. Gasoline was fine in the tanks too....that was till they started adding ethanol.

Which isn't entirely true either. Ethanol was added to our "Winter Blend" in...you guessed it the winter. For years I always blamed the carbs and choke for poor starting and running at the end of the year. I'd bet I got just enough Winter blend to start dissolving some tank resin mixed in with regular non E stuff.

But my first good tank full of that crap...I was out running around after chaning trans ratio, went in for more Go juice, took 1/2 tank and headed back out....that was it, I could not get the boat back up on plane.



Dad had a similar problem creeping up with his gass 440's...but being lucky he stumbled upon a great Diesel deal and converted. He had some tank delamination...but after a good clean tanks been fine. Hatteras boat...they had the other "lifetime" fiberglass tanks.

LOL-- kinda like the lifetime warranty I got from my exterminator...he died...warranty over.

[JeremyD]

LOL well it was a lifetime warranty - just his lifetime, not yours...

[Ironworker]

Ethanol attacks more than the tanks. Fuel hoses should be replaced every 5 years.