IANAPetrochemicalEngineer, but I can't find anything online about MTBE
and ethanol forming precipitates. I've found that the US EPA does
generally forbid mixing the two products in bulk, but there's no ban on
mixing in the consumer's tanks. The rational for the ban has to do with
increased Volatile Organic Compound emissions, not chemical
incompatibility.

The following ethanol industry technical paper states that all
fiberglass tanks designed for gasoline are compatible with
gasoline/ethanol blends up to 10% ethanol, and that it has approval
letters on file from both Fluid Containment (formerly Owens Corning
Fiberglass) and Xerxes Corp, the two major commercial fiberglass tank
manufacturers. (pg. 16) It goes on to say that tank relining materials
using epoxy or polyester resins from the late 1970s and early 1980s are
not compatible. Page 18 has a short chart of compatible and
incompatible materials.

<URL:http://www.e85fuel.com/forsuppliers/rfa_technical_manual.pdf> Or:
<URL:http://64.233.187.104/search?q=cache:RfZSWgiqkhIJ:www.e85fuel.com/forsuppliers/rfa_technical_manual.pdf&hl=en>

Without having looked at the OP's pdf I'm guessing that the boatyard is
having problems with boat tanks older than 1980.


reconair wrote:
> There's really more to it than that. MTBE additives and Ethanol are not
> compatible and will cause precipitates to form that affects fuel line/fuel
> filter delivery and cause combustion problems. When switching from MTBE
> fuel to Ethanol fuel, make sure you run the tank near dry before refueling
> and vice versa. This will limit the effects of incompatibility.
>
> Scott
> 91YJ
> "Rich Hampel" <RhmpL33@nospam.net> wrote in message
> news:040120061152437988%RhmpL33@nospam.net...
>
>>although this affects mainly boats, I thought I'd cross post this here
>>in case any of you have a fiberglass fuel tank.
>>
>>There are great 'problems' showing up due to the 'changeover' of
>>gasoline addives - MTBE to Ethanol: Fiberglass fuel tanks dissolving
>>and leaking, harmful destructive deposits formed inside engines, etc.
>>About half the USA states have already banned MTBE additive and are
>>rapidly changing over to an ethanol additive, the ethanol is quite
>>incompatible with most of the fiberglass resin used in fuel tanks. The
>>decomposition products of the 'melting/dissolving' resin doesnt burn
>>and will form vast and destructive deposits in the engine (similar to
>>putting sugar into the gasoline).
>>
>>for more info:
>>http://www.moyermarine.com/forums/at...ttachmentid=42
>>or BOATUS.com website.
>
>
>

 

The owners manual that forbids the crap makes no differentiation between
the tanks.

I think it has to do with the steel lines rotting and the carb soft
parts melting. I cannot go more that two years on a float needle these
days. The one I have in now is starting to give up the ghost. They
have the soft tips.

My gas mileage and power also goes totally to crap when alcohol is mixed
in. I drop to 16 or 17 mpg from my nice 23 mpg highway and it fights to
hold 70 mph vs only needing a half pedal down with 'real' gas.

Mike

Lee Ayrton wrote:
>
> All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
> but I gather that the optional 20 gallon tank was plastic.
>
> Mike Romain wrote:
> > All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> > tanks and the owners manuals for the 80's vintages specifically forbids
> > the use of any alcohol mix no matter what 'drying agents' they try to
> > con you with.
> >
> > So who came first, the CJ7's or the farmers lobby?
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> > (More Off Road album links at bottom of the view page)
> >
> > Bret Ludwig wrote:
> >
> >> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
> >>materials in the first place.

 

The owners manual that forbids the crap makes no differentiation between
the tanks.

I think it has to do with the steel lines rotting and the carb soft
parts melting. I cannot go more that two years on a float needle these
days. The one I have in now is starting to give up the ghost. They
have the soft tips.

My gas mileage and power also goes totally to crap when alcohol is mixed
in. I drop to 16 or 17 mpg from my nice 23 mpg highway and it fights to
hold 70 mph vs only needing a half pedal down with 'real' gas.

Mike

Lee Ayrton wrote:
>
> All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
> but I gather that the optional 20 gallon tank was plastic.
>
> Mike Romain wrote:
> > All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> > tanks and the owners manuals for the 80's vintages specifically forbids
> > the use of any alcohol mix no matter what 'drying agents' they try to
> > con you with.
> >
> > So who came first, the CJ7's or the farmers lobby?
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> > (More Off Road album links at bottom of the view page)
> >
> > Bret Ludwig wrote:
> >
> >> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
> >>materials in the first place.

 

The owners manual that forbids the crap makes no differentiation between
the tanks.

I think it has to do with the steel lines rotting and the carb soft
parts melting. I cannot go more that two years on a float needle these
days. The one I have in now is starting to give up the ghost. They
have the soft tips.

My gas mileage and power also goes totally to crap when alcohol is mixed
in. I drop to 16 or 17 mpg from my nice 23 mpg highway and it fights to
hold 70 mph vs only needing a half pedal down with 'real' gas.

Mike

Lee Ayrton wrote:
>
> All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
> but I gather that the optional 20 gallon tank was plastic.
>
> Mike Romain wrote:
> > All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> > tanks and the owners manuals for the 80's vintages specifically forbids
> > the use of any alcohol mix no matter what 'drying agents' they try to
> > con you with.
> >
> > So who came first, the CJ7's or the farmers lobby?
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> > (More Off Road album links at bottom of the view page)
> >
> > Bret Ludwig wrote:
> >
> >> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
> >>materials in the first place.

 

All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
but I gather that the optional 20 gallon tank was plastic.


Mike Romain wrote:
> All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> tanks and the owners manuals for the 80's vintages specifically forbids
> the use of any alcohol mix no matter what 'drying agents' they try to
> con you with.
>
> So who came first, the CJ7's or the farmers lobby?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> (More Off Road album links at bottom of the view page)
>
> Bret Ludwig wrote:
>
>> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
>>materials in the first place.

 

All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
but I gather that the optional 20 gallon tank was plastic.


Mike Romain wrote:
> All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> tanks and the owners manuals for the 80's vintages specifically forbids
> the use of any alcohol mix no matter what 'drying agents' they try to
> con you with.
>
> So who came first, the CJ7's or the farmers lobby?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> (More Off Road album links at bottom of the view page)
>
> Bret Ludwig wrote:
>
>> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
>>materials in the first place.

 

All the CJ-7s that I've had contact with had the 15 gallon steel tanks,
but I gather that the optional 20 gallon tank was plastic.


Mike Romain wrote:
> All CJ7's made cannot use ethanol as far as I know. CJ7's have plastic
> tanks and the owners manuals for the 80's vintages specifically forbids
> the use of any alcohol mix no matter what 'drying agents' they try to
> con you with.
>
> So who came first, the CJ7's or the farmers lobby?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> (More Off Road album links at bottom of the view page)
>
> Bret Ludwig wrote:
>
>> The PROBLEM isn't the fuel. The PROBLEM was the poor choice of
>>materials in the first place.

 

Sugar in the gas won't result in vast and destructive deposits, even
though the popular belief is that it will. Table sugar can't dissolve
in hydrocarbons, it might just as well be ground glass in the tank. It
will clog up the fuel sender sock and the fuel filter, but you won't
find caramel syrup under the valves. See:

<URL:http://www.snopes.com/autos/grace/sugar.asp>


Rich Hampel wrote:
> although this affects mainly boats, I thought I'd cross post this here
> in case any of you have a fiberglass fuel tank.
>
> There are great 'problems' showing up due to the 'changeover' of
> gasoline addives - MTBE to Ethanol: Fiberglass fuel tanks dissolving
> and leaking, harmful destructive deposits formed inside engines, etc.
> About half the USA states have already banned MTBE additive and are
> rapidly changing over to an ethanol additive, the ethanol is quite
> incompatible with most of the fiberglass resin used in fuel tanks. The
> decomposition products of the 'melting/dissolving' resin doesnt burn
> and will form vast and destructive deposits in the engine (similar to
> putting sugar into the gasoline).
>
> for more info:
> http://www.moyermarine.com/forums/at...ttachmentid=42
> or BOATUS.com website.

 

Sugar in the gas won't result in vast and destructive deposits, even
though the popular belief is that it will. Table sugar can't dissolve
in hydrocarbons, it might just as well be ground glass in the tank. It
will clog up the fuel sender sock and the fuel filter, but you won't
find caramel syrup under the valves. See:

<URL:http://www.snopes.com/autos/grace/sugar.asp>


Rich Hampel wrote:
> although this affects mainly boats, I thought I'd cross post this here
> in case any of you have a fiberglass fuel tank.
>
> There are great 'problems' showing up due to the 'changeover' of
> gasoline addives - MTBE to Ethanol: Fiberglass fuel tanks dissolving
> and leaking, harmful destructive deposits formed inside engines, etc.
> About half the USA states have already banned MTBE additive and are
> rapidly changing over to an ethanol additive, the ethanol is quite
> incompatible with most of the fiberglass resin used in fuel tanks. The
> decomposition products of the 'melting/dissolving' resin doesnt burn
> and will form vast and destructive deposits in the engine (similar to
> putting sugar into the gasoline).
>
> for more info:
> http://www.moyermarine.com/forums/at...ttachmentid=42
> or BOATUS.com website.

 

Sugar in the gas won't result in vast and destructive deposits, even
though the popular belief is that it will. Table sugar can't dissolve
in hydrocarbons, it might just as well be ground glass in the tank. It
will clog up the fuel sender sock and the fuel filter, but you won't
find caramel syrup under the valves. See:

<URL:http://www.snopes.com/autos/grace/sugar.asp>


Rich Hampel wrote:
> although this affects mainly boats, I thought I'd cross post this here
> in case any of you have a fiberglass fuel tank.
>
> There are great 'problems' showing up due to the 'changeover' of
> gasoline addives - MTBE to Ethanol: Fiberglass fuel tanks dissolving
> and leaking, harmful destructive deposits formed inside engines, etc.
> About half the USA states have already banned MTBE additive and are
> rapidly changing over to an ethanol additive, the ethanol is quite
> incompatible with most of the fiberglass resin used in fuel tanks. The
> decomposition products of the 'melting/dissolving' resin doesnt burn
> and will form vast and destructive deposits in the engine (similar to
> putting sugar into the gasoline).
>
> for more info:
> http://www.moyermarine.com/forums/at...ttachmentid=42
> or BOATUS.com website.