steve chalupka

Last week I had a devastating experience for which I'm seeking preventative advice.
Like most of us around the country here in Illinois we've had 100+ deg temps. I 'm assuming most boaters know that gas expands in the tanks of all boats. The hotter the temps the greater the expansion. Well my beautiful Sonic had maybe 3/4 of a tank full of gas in her tank sitting on my driveway when I was alerted by my neighbor who rang my doorbell informing me that gas was dripping from the bottom of my boat cover. I immediately rushed out and pulled back my full cover (which completely covers the boat down to the hull). The gas which couldn't have been dripping out of the vent for maybe an hour stripped away the clear coat and started eating into my beautiful hand airbrushed paint job. After all the careful cleaning was performed and wax to seal the damaged area was completed I gained my composure and called Mitch Tolan to hire his expert services. I won't go into how truly great this man is for we all know he is the Rembrandt of his craft. He is scheduled to come out and once again restore my paint to its original condition. Like most who own powerboats, my 2004 Sonic looks today as it did the day I picked it up after custom ordering it in 2003. The paint job was flawless.
What I would like to know is how to prevent this from EVER happening again?!
I know the obvious. Don't fill tank. It wasn't. Tanks hold approx. 105 gals. and there was maybe 60 gals. in tank. This cannot be a unique problem to me. How have others dealt with this problem? The boat was backed into my driveway with bow facing slightly down. Cause of the problem? Not absolutely certain.
Are there any additives that keep expansion down etc...
Thanks for any advice/help anyone can provide.
Steve -

c_deezy

iTrader: (1)

The bow down was certainly a contributor. That would normally be the high side of the tank and where the vent is. Instead of venting when the gas started expanding, it started purging. Keep that bow up and the fuel at the back of the tank.

You may also consider trimming a hole in your cover where the fuel vent is, so it vents directly to atmosphere.

stevesxm

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

befu

iTrader: (2)

my vent line on my 86 272 enters the tank at the back, right next to the fill port. Two pickups, one vent and one larger fill port all at the back.

Does anyone know if the vent line has a tube running to the front of the tank? I would think it would have to, otherwise it would be submerged with anything over 2/3 tank. Have not run it or filled it since I picked it up in the winter and seeing how it is 24 years old, must not be a problem.

For your problem, I agree it is an air expansion issue, not a fuel expansion issue. somehow the air was trapped and pushed the fuel out.

Brian

FIXX

iTrader: (2)

their was most likely is their was fuel in the over flow hose already and when the tank farted it pushed the fuel out...you can legthen the over flow hose and put a big loop in it so it holds more fuel..when you psrk the boat loosen the fuel caps just enough so it can vent instead of venting through the over flows.

doesnt your paint guy use polyurathane clear after the air brushing is done?? gas should not hurt the clear..

steve chalupka

I was told the graphics are in fact clearcoated with imron. Gas leaking over them for say over an hour would however, (again as I'm told by people in the know not me for I am NOT an expert) will get to the paint by breaking down the clear coat. I'll verify. Mitch T. will be at my place in a couple of weeks. He in fact IS an expert. My understandig was yes occassional gas spill will not hurt. If the gas is running over the same area for an hour or more it will penetrate clear coat Imron or not. Again Mitch will be able to tell determine.

Boat was painted (as all Sonics were at that time) by Fred at factory. My wife actually saw boat being painted because she was on a business trip near Hollywood, FL at that time.

I did unscrew the main gas cap as mentioned to vent. The gas still came through the vent.

stevesxm

i painted race cars for 25 years with imron and absolutely nothing would soften it after cure. no solvent, no paint remover, nothing at all would affect it. the mechanics would routinely clean the cars with lacquer thinner to get the heavy grime off them after the long distance races and the paint would look new. if your stuff was clear coated in imron, no fuel from this planet would have affected them. now... IMRON is a dupont product that is a urethane based 2 part expoxy... and there are LOTS of 2 part urethane epoxies made by a lot of people that are about 1/10 the price. it is not uncommon for people to use the term
" imron" as a generic like they use the word xerox. all i will say that if genuine dupont imron was used then there would have been no issue.

MILD THUNDER

iTrader: (3)

this happened to my buddy's fountain too during this last heat wave. Just sucks.

keith2500hd

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.

FIXX

iTrader: (2)

this is whats's happening then,,when he paints or fix's the graffix the fuel over flow fitting needs to be removed or loosened then cleared..when you mask around the fitting then the fuel will get under the dlear and distroy the graffix or the base cat.. i have seen the way some of the guys on paint the boats and instead of removing the hardware they mask a circle around it and instead of removing the masking tape and making another line and then clearing the edge to seal off the inner base coat they leave..then thats where all the problems start...i have imron on my donzi,,the whole boat and its 12 yrs old..i have spilled gas on it and left the rag i wiped it off with on the top side of the boat because i forgot about it and it did not hurt the finish at all..if they are saying its like imron its most likelt not..from what i understand i believe one guy that does chstom work on here use's transstar clear which is not imrom,,poly matbe but not imron..