Fuel vapour in bilge cavities

[John Ellis]

I have just purchased a 195DC here in Australia and previously asked for advice regarding the installation of an auxiliary outboard bracket. The bracket has been installed and I'm happy with the result. I did however notice that whenever I open an access hatch in the deck or transom, a very strong fuel vapour odour is present. Given that the inlet and vent line are plumbed to the exterior of the transom I am concerned that there is a leak allowing vapours to accumulate in the bilge. As this is a new boat and the battery terminals are exposed and in the same space the explosion risk comes to mind. When I asked the dealer about the fuel odour he said that they all seem to have that. I'm not really satisfied with that response. The fuel tank is basically MT at present so I'll keep an eye on the bilge for any signs of a leak when I do get around to filling up. If the deck is glued down with sealant/adhesive, it's going to be rather difficult to investigate the cause. Does anyone have any advice or experience with this problem.

Regards

John Ellis

[cagrove]

John,
What you're smelling may not be fuel vapors but instead a smell that the Roplene gives off and seems to accumulate in confined spaces. It smells very much like gasoline just not as strong. There are several posts on the subject in the forums on this site. I know on my 170CC that when I open the seats to access the bilge and tank areas that it always smells like fuel...I merely leave the seats open so it can vent. That would explain your dealer's response that all Triumphs seem to have that odor.

Here in the States, you can take your boat to a local fire department and have them use a "vapor sniffer" to determine if it is actually gasoline or something else. I'm sure your local FD can do the same for you. You may get a warmer reception if you show up with some edible goodies for your local heros.

Tight lines.

[John Ellis]

Thankyou very much for the feed back. I've just had a good look around in the bilge and can't see any fuel. The connections all look sound and the smell did subside considerably after the hatches were open for a few minutes. I guess it's something I'll just have to get used to.

Regards

John Ellis

[Thfireman]

John,

I also have the 195DC. As you I was smelling what I thought was fuel in the hold. It made me wonder if there was a leak or maybe the fuel tank was permiated with the fuel odor. I asked about that at the dealer and they told me that it is the Roplene. At first I thought it was a "Get him outta our hair" answer but after I started paying close attention it smelled different than the fuel in the boat. I now store my 195 with the battery door, bilge cap and front storage area open so the smell wont build up. It helps me not worry about it. A month ago a machanic friend brought his vapor meter over at my request and I left the ports shut till he got there. It was hot that day and the odor was quite strong. He put the vacume tube in the bilge in several areas and the O2 content only dropped 1% and there were no other harmful vapors detected. He then put the meter near the fuel vent on the transome and got a moderate reading from the escaping fumes. This convinced me that it was not fuel vapor in the builge. Now I can vent out the roplene odor and have fun without worry.
Roger

[John Ellis]

Thankyou for your response. That has put my mind at rest.

[NCangler]

From the factory:

There will be a permientation of fuel smell that you can smell in the bilge area, that is the nature of the fuel tank. However if you are really concerned that this is more than the tank smell, you can take your boat in and have the fuel system pressure tested. That will tell you for sure whether or not you have a leak.

[Thfireman]

I think this is also a good idea to put another thing in the mind to help you rest at ease. I might have them do that anyway next time I go in sor routine service. A few bucks more for piece of mind wont kill me.... Maybe that is a bad choice of words, LOL.

Also I thought I read in the Coast Guard manuals or some sort od Regulatory Manual that if the fuel tank was enclosed in the hull that there is supposed to be vent fans installed to vent built up fumes. Is this true or was I just dreaming. If it is true My 195 is lacking the fna as far as I can tell. If it is true shouldnt it have been put in at the factory? I am sure they are up on all that code and legal stuff. It might just be a certain size craft.

[pamarine]

The requirement is that every boat manufactured after August 1, 1980 that has an enclosed engine compartment or enclosed compartment with a fuel tank (when the engine and/or tank is for gasoline or other fuel having less than a 110 deg F flashpoint) except where the tank isvented outside the boat and contains no unprotected electrical devices be equipped with a ventalation system consisting of at least 1 air inlet and 1 air outlet. As far as I know, all the Triumph models have the gas tank vented to the outside by a vent located near the fuel fill, therefore not being legally required to have a ventalation system. Powered ventalation systems are only required for vessels having a enclosed gasoline engine with a cranking motor. Notice that there is no requirement for Diesel powered vessels. This is because diesel eninge require such great volumes of air to support combustion that boats powered by them are normally designed with adequate ventalation systems. The ABYC (and by extension NMMA, by whom Triumphs are certified compliant) recommends that every vessel have a ventalation system capable of removing combustible vapors from enclosed spaces while underway by means of at least one intake and exhaust vent and necessary ducting. Again, the only time a mechanical ventilation system is required is if the vessel is equipped with a gasoline engine with cranking motor mounted in an enclosed space. I have noticed that several manufacturers are NMMA compliant without meeting all ABYC recommendations. It seems that NMMA will certify a vessel design if all reasonable attempts to meet ABYC recommendations have been made and all USCG requirements are complied with. I hope this helps.

[Thfireman]

Thanks, That explains it pretty well. I think I will still leave the hatch's open when stored and in transit just to get fresh air in there, if for nothing else but to prevent mildew. Thanks for the explination.