Gasoline Odor- Bad Old Hoses?

[bollard]

Could the strong gasoline smell that I am detecting be due to old (15-years+) fuel hoses? I have quite a nest with dual tanks going into a tank switch and then dual fuel/water filters into twin outboards. The smell seems to be confined to the area where the hoses are. The boat has never seen the shade (South Florida), though the hoses are all below deck. Could this be "fuel permeation" of the old rubber? I have never (knowingly) used alky mixed gasoline and there are absolutely no liquid fuel leaks. I routinely replace the exposed hoses and primer bulbs which dry and crack in the sun, but the under-deck stuff still looks and feels to be in good shape.<br /><br />TIA<br /><br />Bollard

 

[JB]

Re: Gasoline Odor- Bad Old Hoses?

If you can smell it, it is a bomb waiting to explode, Bollard.<br /><br />Probably a leak that you need to find and fix ASAP.

 

[Scaaty]

Re: Gasoline Odor- Bad Old Hoses?

Agreed. All it takes is a drop, and it will stink up the bilge. I had a bad hidden crossover hose on one of my motorcycles, and with three bikes in one area, I could not find it. Had to take them and bring in one at a time over night to find out which one it was. You MUST find the leak. New hoses could not hurt. Like JB says, this is a serious issue,

 

[Moody Blue]

Re: Gasoline Odor- Bad Old Hoses?

Remove the keys from the ignition, shut everything off and slowly back away from the boat. If gas was permeateing throught the hoses they would be wet not just an odor. You DO have a leak somewhere if you can smell gas. If you can't locate it, have a professional take care of it for you.

 

[timmathis]

Re: Gasoline Odor- Bad Old Hoses?

It could be a float adjustment in a carb. Like they say you must find the leak or whatever the case. Gas leaking in a boat is a time bomb!!!<br />It will hold the fumes and any kind of spark and BOOM it could be all over.... <br />Tim

 

[bollard]

Re: Gasoline Odor- Bad Old Hoses?

What is "fuel permeation" and why is it mentioned in the specs on new fuel hose? Will permeation cause the hose to be wet with fuel, or can just the vapors get through the old rubber? Without going into Darcy's Law detail, the relative permeability of a gas (vapor) is higher than a liquid through the same material, so can't gasoline vapors penetrate 15-year old hose without the hose actually being wet with fuel.<br />Still chasing my problem....

 

[bollard]

Re: Gasoline Odor- Bad Old Hoses?

Maybe I found the answer. I think my old hose does have too much permeation due to its age. Even new hose has a small amount of vapor penetration (at least in California!).<br /><br />"SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours.<br /><br />SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square meter of interior surface in 24 hours."<br />"The permeation rating of the hose refers to the quantity of fuel which will pass through the walls of the hose out into the boat when the hose is filled with fuel. You could think of this as a slow leak. Fortunately, the fuel vapors formed by this low level of permeation are readily dissipated by the ventilation system."

 

[Scaaty]

Re: Gasoline Odor- Bad Old Hoses?

Ya know, if those tanks are in the hull, and also 15 years old, one or both could very well be corroded through, and you are soaking the hull, a VERY serious issue. I would just quit deducing what could be, and rip all the hoses out, new cross-over, and before putting any thing back, air it out. If it still smells, you have tank problems. Not uncommon, regardless of tank material.

 

[bollard]

Re: Gasoline Odor- Bad Old Hoses?

Problem solved!! It WAS a fuel vapor permeation problem. The hoses were type B, dated 1989. Replaced everything with new type A1 (used 42' of a 50-foot roll). I had a lot of exposed surface area where vapors were permeating since I have 2 tanks, 2 engines, 2 fuel/water filters and a switching valve.<br /><br />So, even if your tanks are 27 years old, the odors that you smell may be the old hoses, especially if they are the inferior USCG Type B. Note that the odors were concentrated in the port side area of the hose "rats nest", but never detected in the lower bilges. That was my tipoff to try something else before considering tank replacement.

 

[sonus]

Re: Gasoline Odor- Bad Old Hoses?

Just to add my two cents,Ive come to the same conclusion on my boat.Had fuel odor limited to the enclosed fuel tank compartment under the deck.Lucky I have a easy access tank,After removing the floor;draining,removing and cleaning the grimy tank,it looks to be in fine condition.I now think its the 1983 USCG TYPE B fill hose.The hose will be difficult to replace because it seems to be foamed in.Will work on it and put it all back together in the spring.