odor of gasoline/Tom Cat 25 cabin

[kevin ware]

Has anyone had a problem with a a slight but persistent odor of raw gasoline in the cabin of a Tom Cat? Ours has had this problem for some time, and we have yet to figure it out.

We initially thought it was residual from the dinghy outboard stored in the head, but stopping that practice did not resolve the odor problem.

I have checked the bilges on both hulls and have not found any evidence of gas sloshing about, but the odor is so slight it would surprise me to find such a quantity anyway. Just to be compulsive, I flushed both bilges with dish soap (it takes the odor away from just about anything) and fresh water, without improvement.

Carefully checked all the hoses near the stern and find none of them leaking, and really, the stern is relatively gas odor free.

I am suspecting it may have something to do with the vent lines, or the tank/hose connection. Anyone had experience with inspecting those locations? If so, how did you do it?

How about a hatch for the tanks themselves. Do they have one? If so, any leakage history?

Input would be appreciated.

Kevin Ware
El Gato Thomas
Tom Cat 25.5

[Wandering Sagebrush]

Kevin,

I don't have experience with the 255, but we occasionally get light fuel odors in our 22. I think there have been previous threads on this, but my suspicion is that it's outgassing of vapor through the plastic tanks. Let's see what others have to say.

Steve

[rogerbum]

There are no plastic tanks on the TC255, the tanks are aluminum. Unfortunately, there are no inspection hatches and the tanks are almost impossible to get to without cutting out the floor. There are two inspection plates on the gunnels (one on each side) just below the fill valves. You can open those up to look at the connections there. I rather doubt you'll see a problem there but it can't hurt to look. There is at least one case that I know of (in a CD-25) in which the aluminum tank developed (a) pinhole leak(s) due to corrosion. See this thread about that.

[BrentB]

Idk
Is the tank plastic or metal?

[rogerbum]

You can see the forward end of the starboard side tank (at least in my TC255) by removing the starboard cover on the sole under the sink. I think there's also an access area on the port side in one of the cabinets, but I've never had a reason to look over there.

[gulfcoast john]

Hi Kevin!
bottom line...install inspection plates and replace your fuel gauge sender units.
We have aluminum tanks, no smell issues ever.
To inspect the gas vent line to deck fill connections, we unscrew the gas vent to deck fill inspection plate and look around.
To inspect the gas tank connections, we unscrew the gas tank connections inspection plate and look around. It's at sole level under the upper inspection plate. No big deal to cut one out if you don't have one.
Our surveyor said they are a good idea, tho not 'pretty'.
Your next best access would probably be to remove the cockpit side storage bins (8 screws). I doubt you could reach anything on the tanks from there, but at least you can see what to avoid when you saw out holes for your new inspection ports without cutting the helm/engine control rigging which all runs behind there (starboard side) plus the stray depth transducer wire and 12v lines. If you can reach them, you could wrap a cloth around different connections while running, and if the cloth smells, you've located the problem. Agree with Roger (as usual), if you have a removable hatch in the galley floor (starboard) or cabinet floor (port) you may be able to see the forward aspect of your gas tanks from there.. Any gas or odor in either sponson aft of the forward bulkheads (at rear ends of V-berth) has multiple pathways to get into the cabin. 1 drop of gas in a sponson will be detected by most noses.
I would replace (or hire it out to a non-smoking mechanic) the gas tank gauge senders and/or at least the gaskets because they are a frequent culprit and cheap to replace. They each have 5 bolts that should be sequentially torqued down correctly but often aren't, a cheap fiber gasket designed to last the 12 month warranty, and a pink wire to your gas tank gauges. Yours have lived far beyond their 12 month warranty, and as electormechanical cheap devices living in gas...well, it's a wear item. Look at some on the wall at West Marine and you'll see how cheaply made they are, including the cheap fiber gaskets. I have replaced fuel gauge senders in all of my 13 boats except the Sunfish and Hobie-16.
My understanding is that all gas hoses in boats should be replaced with ethanol- resistant (4 times more expensive) hoses at 10 years from the HOSE MANUFACTURE date (not your boat model year date...but if you have a 2007 255 it could be rigged with 2004 hose). Maybe sooner if you run E10. In less than 3 years, you'll have to replace all your hoses which can only be done through inspection plates you don't have....the Buyers surveyor is going to cut that from your asking price anyway, so you may as well pay now. Tell the wife 'it's a safety issue'.
But maybe your new senders installed through your new inspection plates will fix it.
Hope someone has a better/cheaper/easier idea that works...
Cheers!
John