Ethanol damage to Bertram gas tank

IRGuy · Post by **IRGuy** » Wed Apr 01, 2009 6:38 am

The link below will take you to a set of pics taken recently during a diesel repower of a gasser B31, including replacement of the original gas tank.. you will see one pic taken of the inner surface. Lots of surface deterioration! http://www.rockvillemarine.com/projects/8 I lifted this from Bill McKinnon's post titled "Almost finished".

Post by **dougl33** » Wed Apr 01, 2009 8:04 am

Given the age of that boat, I wouldn't be suprised if some/most of that damage was already there. The tank on Al's 78 was detiorating and it never saw a drop of ethanol.

IRGuy · Post by **IRGuy** » Wed Apr 01, 2009 9:46 am

Doug... I made a typo and forgot to put a question mark at the end of my subject heading. I mention ethanol because the boatyard said it was ethanol damage in the paragraph intro to the pics.

Post by **dougl33** » Wed Apr 01, 2009 10:24 am

Yeah I know. I read Bill's comments on the 31 site. He actually said that the tank had "minimal exposure" to ethanol. With the early boats, it seems like that's all it takes. That being said, until ethanol popped up I'll bet very owners looked inside their tanks, so who knows what they looked like before.

IRGuy · Post by **IRGuy** » Wed Apr 01, 2009 12:08 pm

Doug... I have stayed away from putting my 2 cents worth into any ethanol/fibreglas tank discussions because my boat has only seen diesel fuel and I have tons of other boat related stuff to occupy my mind.. but I suspect you are correct. I would not be surprised if exposure to gasoline liquid and vapors for many years would in itself cause some type of surface damage, if not structural damage, to tanks made so long ago.. considering the formulations were probably the best Bertram could come up with at the time, but over time new components were developed and builders learned more, and probably fibreglas tank formulations and fab techniques changed as a result.

rnanaples · Post by **rnanaples** » Tue Apr 07, 2009 4:27 pm

I am goiung to go ahead and jinx myself here. I have run at least 1000 gallons through my tank on my 78. I did put a very fine micron double canister filter before the merc filter. One other person suggested he did the same and had no problems. I may be really off base here but until I see problems I am going to stay as is. I have heard many wives tales over the years that turn out to be total bs after people spends countless dollars.

otf · Post by **otf** » Wed Apr 08, 2009 3:09 am

Lacking another explanation, the signs in my 83 were undoubtable due to ethanol. Given the boat was used rarely prior to problems and repairs.

Justinf89 · Post by **Justinf89** » Wed Apr 08, 2009 8:05 am

I've had no problems so far with mine. I've ran at least 1000 gallons also with great luck. I have 2 micron secondary filters on that I haven't changed in like 4 months, guess it's time...

otf · Post by **otf** » Thu Apr 09, 2009 8:51 am

I tend to think (I'm no expert!) that if the fuel is run through in good time it will have less of a chance to do whatever it does (told you I was no expert) and cause problems. In other words a little bit of bad stuff does no harm, a lot will. Honeslty, at least in my boat it really isn't a hard job. I would say it is easier than pulling the motors. But then agian, I haven't doen that yet.

franklyprice · Post by **franklyprice** » Thu Apr 09, 2009 9:38 am

It's the water. Keep out the water and you'll be fine for the most part. That damage is a classic water permeation problem. The ethanol may have helped it along but in my tests the water is what did the damage to the glass, the ethanol fuel is still doing nothing.

rnanaples · Post by **rnanaples** » Fri Apr 10, 2009 4:07 am

I just have to wonder if you did not get a heavy layer of varnish fomr the previous gas sitting and the ethanol broke it all up. quote:Originally posted by otf Lacking another explanation, the signs in my 83 were undoubtable due to ethanol. Given the boat was used rarely prior to problems and repairs. Scott 1983 Bertram 33 FBC Andiamo

otf · Post by **otf** » Thu Apr 16, 2009 3:13 am

Could have been a varnish from the previous gas. Not a bad idea.