We have owned our Freedom 39PH for about six years now. The cabin had a mild diesel smell when we bought her, but nothing that we couldn’t live with. Started keeping a a diesel absorbent pad in the bilge after noticing the tell tale rainbow of our discharge. There was just a trace, but it doesn’t take much diesel for the smell to permeate the boat particularly in very hot weather. We scrubbed and cleaned, checked hose connections, wiped hoses we could reach all to no avail. I did see the faintest of diesel track coming from an inaccessible, without major surgery, the lowest corner of the starboard tank.
We weren’t getting any younger, and the smell wasn’t going away. It was time for action. The entire starboard cabin interior was disassembled to gain access to the fuel tank and out she came. The tank was set in foam, that’s the was they did it back in the eighties. The foam reeked diesel smell and even dripped diesel. Off went the tank to a shop to be pressure tested. Several days later got a call from the shop, “we can’t find no dammed leak.” I didn’t know what to think. Maybe they didn’t want the job. Maybe they didn’t know what they were doing. The tank looked to be in good shape so I decided to take it home, clean it out, fill it with water and if it didn’t leak put it back in the boat.
New tank or old the foam it was sitting on had to be removed. It was wet with diesel from the bottom all the way up to the top. I was puzzled. What was the source of the diesel? Scratching my head, look at the mess I noticed several brownish lines in the hull going up under the fiberglass holding the water tank bulkhead. When I had disconnected the fuel and vent hose ten or so days earlier I had noticed that the vent hose felt rather soft and gunky. Light bulb! Took a step over to the vent hose that had been disconnected to inspect and a few cc of nasty yellow gunk came out of the hose. I then felt with my hand the vent hose as it went back all the way to the stern of the boat. It’s not readily accessible to your hand, but every place I could swipe with my hand in the low places between the zip ties holding it to the electrical conduit I came up with this nastyness.
My understanding is for boats built in the 80 (I don’t know the exact dates) the vent hose was not required to meet USCG standards for crush-ability and permeability. I think this could be a major reason boats of this vintage often suffer from the dreaded Cabin Diesel Smell.
HG