Offshoreonly.com - Gasoline expansion in fuel tank

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A vent in the front of the tank and one in the rear, with a tee well above the tank connecting the two lines would help. That way, no matter what the attitude of the boat, it would gent the vapor and not the liquid.

Quote:

Originally Posted by steve chalupka (Post 3733602)

Lot of good tips/ comments here. I too spoke with Mitch for almost an hour a couple of days ago arranging his visit. He gave the entire history of paint (Imrom ,PPG, clearcoat, poly acrylic etc..) more info than I could possibly retain. he did say with certainty.
ABSOLUTELY NO PAINT (IMROM clear or otherwise) will resist gasoline if left on a paint finish for 1/2 hour or more period end of story and he is the undisputed expert in painting!

Here is a pic of mine.

http://i7.photobucket.com/albums/y27...IMG_0370-1.jpg

mines been puking gas out of the vent for 3 days now,,i just wiped it off...no damage and the sides are solid white imron with imron purple and uellow stripes..seems mine is over 12 years old it must be the new imron thats doing it or the cheap trans star clear.

Quote:

Originally Posted by stevesxm (Post 3730093)

this is exactly correct. the fuel will expand about 2 % before it goes to vapor so there was no 25 % expansion... what happened was the angle of the boat trapped that 25 % air in a non vented space... then that air pocket expanded with the temp and pressurized the tank and pushed the fuel out the first opening it found. and if you clearcoat your graphics with imron, absolutely nothing ... and i mean nothing at all will hurt them. ever

This guy is right fuel expands but not as much as one would think specially if the relatively small amount of fuel in a boat. I used to do fuel in the Army and we had some fancy chart that explained each temp and how much percent gain or loss in actual fluid there would be, and its really small and really only had an effect on huge amount of fuel. But like others it was the pressurization.

Never store bown down, you shouldnt anyways to let rain water drain out out the transom plug, if it gets really hot try opening the fuel door. Also never leave the boat more than 3/4 full during hot hot days

Quote:

Originally Posted by mrfixxall (Post 3733820)

I agree Ive had multiple boats with puking and fuel spills and never had any damage.

Quote:

Originally Posted by keith2500hd (Post 3730634)

you can plumb into the vent line a catch can with top and bottom fittings, run vent line into bottom and continue vent hose out of top to external vent. mount can upright, summit has SS(pn sum-300102). this will allow liquid to fallout of suspension, you can get attwood surge protector(pn 1675-6) vent to stop any liquid from puking out. you want steady rise on vent line, no loops or dips, they can hold liquid and block venting. simpler option, get cpperformance EFI return and tee off threads so vent line liquid fuel will go back into fill instead of out vent line.

Thanks for the tip! My fill and vent are at the back of the tank, it always blows out the fill and vent when I try fill the tank full. I don't think it's the ethanol that's eating the paint, it's probably the toluene they add to the gas as a detergent. Ethanol is not that hot of a solvent. I had Mitch paint my boat and I've spilled gas on it multiple times, it still looks new.

Quote:

Originally Posted by steve chalupka (Post 3733602)

well... i will resist being my usual tactless and judgemental self anot not say that your guy doesn't know what he's talking about but when i read this this morning i said to myself... " gee.. this guys doesn't know what he's talking about" . so i went outside and got the test panel that i had done in imron a year ago thats been laying outside in the carrbean sun for about 200 days unprotected and i also cut a piece off an old nissan maxima fender that i had in the junk pile and submerged them both in fuel at 6 am . thats 5 hours ago with raw exposed edges... at last check , 10 mins ago , the paint on both was still hard as a rock. now... i would expect by tomorrow, the nissan part may ... MAY curl an edge where the fuel MIGHT have softend the primer underneith, but the imron which is hard as rock right now, will still be hard as a rock tomorrow and ill bet i can leave it there essentially forever with the same result.

when i was using this stuff on the cars, the most aggressive paint strippers you could buy would just sit there and do nothing. to suggest that a casual fuel bath will wash it away is ridiculous.

addendum.... now a full 24 hrs later and parts removed from fuel immersion... imron part untouched and is as new. nissan part also untouched... even the edge and with a hand rub with a polish, looks perfect.

draw your own conclusions...

Quote:

Originally Posted by stevesxm (Post 3734104)

I would agree whoever painted this boat either used the wrong the stuff or didnt know what they were doing. I have had diesel overflow on my trucks and stay on there all winter along with road salt and such and in the spring after a wash and wax was like new

Quote:

Originally Posted by stevesxm (Post 3734104)

NO pics then it never happened
:evilb: