Fuel In The Bilge

[rajhnsn]

After a five hour motor from Rock Hall past St. Michael's on the Miles River, we anchored behind what is known as Long Pt. Island at about 1600. I had checked the bilge before we left and found an inch of rain water that I assumed came down the mast earlier in the week. I did not check it when we arrived at our anchorage. Soon after arrival, our entourage of eight was picked up by a friend and taken to a family barbecue at a spectacular home overlooking the Miles River. We made our way back to the boat at about 2330 blanketed by a star filled sky. After saying goodbye to our host who had given us a ride back to the boat, six of the crew settled in with a nightcap and constellation identifications when one of the crew mentioned casually, "I smell something kind of like gas." This of course sent me into a search for the source of the smell which I easily found. There was six gallons of diesel fuel in the bilge. I sent everyone above and ripped the boat apart to determine the source to which I could not find. The leak seemed to have stopped with the fuel tank showing 1/2 full. We left with 3/4 full. The needle would normally not show much movement after a 5 hour motor.

The next morning our host returned with two contained to which we pumped the fuel. After checking all visible sources for the leak power on and off. We decided to motor back to Rock Hall and check things along the way. We made it back without any additional fuel in the bilge and the fuel tank read minimal change after a four hour motor. We had wind for about an hour.

I checked the boat again yesterday to find no change in the bilge. I inspected the engine again and found the area around the fuel pump to be wet but when I ran the engine again, I did not see any change. It did not seem like it was leaking six gallons.

I can see about 3/4th of the tank. There are no visible signs of leaking. If the tank was leaking why would only 1/4 leak out and stop if it was from the bottom?

Any ideas on where this leak may be would be very welcome.

 

[Snotter]

If you have a mechanical lift pump, check the diaphram. Also, if you have an electric fuel pump, is it regulated? My old auto-parts, unregulated, fuel pump ran at such high pressure that it was always causing new leaks to appear.

How about your fuel tank--how old is it? Fuel tanks like to corrode in places you can't examine them.

 

[jibes138]

I replaced my fuel tank last year and found corrosion between the board that holds the fuel pump and the tank but down below where the battery sits. You can't see that area without removing the fuel pump and then that board. The screws they used for that board were a little long and one of them had the point touching the aluminum tank and it corroded a pit right through the tank. DaveM had the same issue. I also found a split in a fuell line so it only leaked while the pump was energized but the fuel would run down along the hose so it was dripping in an area that was not readily visible. If your fuel hoses are older than 10 years replace them all. Both SailingCal21 and DaveM have replaced their tanks also so contact any of us if you need additional info. You can get a new pump at NAPA if you need it. My guess is you have a fuel line leak as a hole low in the tank would keep leaking. Are you sure you had 6 gallons of fuel and not 6 gallons of water with a small amount of fuel in it? Sloshing around it kind of forms an emulsion. If you put some in a mason jar and let it sit for a while it will separate and you can get a better idea of what mixture it is. Good luck with it. In my case more fuel was coming from the hose than the tank. Its' a pretty big job to replace the tank but not that expensive, just a lot of labor.

 

[rajhnsn]

Thank you for your comments. There is an electric fuel pump and a lift pump on the motor as far as I can tell. When I run the electric fuel pump alone I don't see any evidence of a leak. Its hard to tell if the tank is original or has been replaced by a PO. I think it is painted steel. Most of the hoses have been replaced at some time but there is one section that looks pretty old. The first five gallons that we pulled out looked pretty clean. I'll send our host an email with this link to see what may have settled. The second container that we sucked out had a considerable amount of debris. I'm hoping it was just dirt in the lower bilge and not part of a rusted out tank. The tank is likely painted steel. The fuel pump is located away from the tank but there is a board between the batteries and the tank. It may warrant closer inspection.

 

[jibes138]

The original tank was aluminum and not painted. I wouldn't draw any conclusions about fuel quality from pumping out the bilge. You need to take a sample directly from the tank to do that. Remove the mechanical fuel gauge and stick a piece of pipe down to the bottom. Put your thumb over it to make a seal then draw it out and drain it into a mason jar Any water will settle to the bottom.
Your pump I assume is mounted on a piece of plywood above your battery tray and forward of the tank. The board it is mounted on is tied to the tank cradle by another piece of plywood they used to screw the pump mounting board together with the tank cradle. Those screws were a little too long and with a little moisture the point of the screw will galvanically react with the aluminum and make a nice pit. Here's a picture of my tank so you can see what I mean.

 

[jibes138]

Running the electric pump alone should circulate fuel through the system. Open your bleed screw to increase the flow and check for leak that way. Hard to believe a leaking tank would seal itself up magically? Another place to look is the injectors. Lift up the floor board under the stairs and see if there is a stream of fuel. Clean that trough out and put in a fresh absorbant pad rolled. Put new pads all along the trough from your stuffing box to the front of the engine. Now you can see if the new pads get soaked with fuel to give you some idea where it is coming from. Nothing worse than diesel fuel smell and it takes a while to get rid of it. If the tank is leaking clean out the trough until it is dry and you should see a stream form along the trough under the stuffing box. You could also build a little dam in the trough with some butyl tape or caulk to see if it collects and fills up behind the dam. It doesn't take much fuel to contaminate water, it turns into a brown sludge looking stuff and stinks like hell. Your original post said you motored for 5 hours. If you were burning 2 gallons an hour that is 10 gallons, you would definitely see the gauge drop since that would be 1/3 of a tank. At 1 gallon per hour it would be 5 gallons and 1/6 of a tank. Either way a noticeable change in fuel level should show up on your gauge. If you normally don't see the gauge move when motoring for that long you likely have a gauge that is not working correctly. Pull it out and see if the float is sticking. You can get a new float gauge if you need one. Maybe you only have a small fuel leak and bad gauge? Any fuel leak is bad and needs to be fixed immediately. Pumping fuel overboard can result in massive fines from the EPA in the 6 figure range.

 

[rajhnsn]

jibes, you are the best! Great ideas. I have cleaned out everything I could get to including the trough. The tray under the motor had liquid as well. The liquid in the tray was black but less viscos than oil. The liquid in the bilge was clearly red. I've asked our host to examine the fuel that we pumped out to see how much water has settled out. He'll get back to me. We are going down this week end and we'll implement procedures you suggest. When you removed your tank, did you take it through the 1/4 birth? I think I like the idea of the poly tank and a smaller size that can be removed relatively easily for cleaning. Even though they do not last as long as other materials, if they can be replaced easier, I think I'd be better off.

I have a sump in the bilge so I don't think fuel made it over the sump dam into the bilge pump area. I've been wanting to put a second bilge pump in outside the dam but I'm glad I didn't.

 

[rajhnsn]

Here is the report about how much water was in the containers of fuel that we pumped out of the bilge. They were five gal jugs. Second jug had about 1.5 gals.

"The second jug had more water than the first. Still, only 1 - 2%. Hardly
any water."

 

[jibes138]

Wow, that's a lot of fuel. SailingCal21 gave me the idea to cut a small piece of the fiberglass above the door in the quarterberth to allow me to get the old tank out intact. I used an oscillating tool and took out a piece about 6 inches wide and maybe a couple feet long. It was so much easier working in their afterward to install the new tank. The idea is to then put the piece back by attaching it to a plywood backing board and then some hardwood trim on the front side. I went with a 23 gallon tank because it had an angled spout that goes right where you want it for your fuel fill and vent. I built a new cradle and fit it to the hull with shims and bonded it in with woven glass on the port side and screwed to the side on the starboard side. The front piece can be unscrewed and removed so the new tank can slide right out for replacement. The wood is pressure treated and I coated it all with epoxy also. I had to buy a sender that had the fuel return port built into it, but the total cost was pretty low. I found a lot of materials at auto parts stores and hardware stores at much cheaper prices than marine supply places. For example NAPA auto stores carry fuel hose, NAPA also had the Facet fuel pump. The oscillating tool is a miracle, it made the job so much easier, everything from removing all the old cradle wood to sanding the hull for bonding the new cradle, to shaping shims to fit the shape of the hull under the cradle. The new system is solid as a rock and replacement will be a snap. I have more pictures on the thread where I did the job if you want to see them.

 

[jibes138]

Here's the link to the thread about replacing my tank. http://forums.oday.sailboatowners.com/showthread.php?t=151661

 

[njlarry]

If I read it right the tank went from 3/4 to 1/2 and stayed there?
Could it be a break or leak in the vent or fill hoses?
You would expect some staining at the point of the leak with that much lost.
Every tank I've seen leak (only a few) always leaked at the very bottom, so if that is it, it should still be dripping?

 

[25yearslater]

I think we are all facing or have faced tank replacements Raj. With my Atomic bomb not only did I have severe corrosion in the bottom of my steel tank but the fuel bowl on the side of the engine had several pin holes that loved spraying gas all over. You might remember that from And so it begins. Wouldn't be surprised if your tank had leaks at the half way point and a busted gauge. Good luck.

 

[rajhnsn]

We inspected the entire area again this past weekend. The fuel gauge had moved to 1/4 but no more fuel in the bilge. This would seem accurate since motoring for about 4 hours from St. Michael's starting at 1/2 tank. Float may have been stuck. We went for a sail on Saturday in about 10 to 14 knots of wind. Closed hall on both tacks for extended period of time. There was no new fuel in the bilge but the smell seemed to be stronger. My conclusion is that there is a hole in the tank about 1/2 way up. I plan to replace the tank with the one that Jibes used. Moeller 23 gals. I'm thinking that I will cut the old tank out after draining and blowing it dry as Dave M did but I'm not locked into this yet. Looking at Moeller's web site, the revisions indicate that the dimensions have changed to 14 inches high creating a 28 gal tank. Does this mean they no longer make the 23 gal? Does anyone know the height of the opening in the quarter berth? Is it at least 16 inches? I don't see a listing of distributors on the Moeller site either. West Marine and Defender carry the tanks but they do not list the size. I would imagine a few phone calls will answer this but if anyone has information, please let me know. Lastly, the Moeller 23 gal does not have a return fitting. Will they install this if asked? My concern is that failure points on plastic tanks are usually at the threads and fittings. I would prefer the manufacture install this.

The existing tank is not magnetic so I think that it is in fact aluminum. The tank is painted the same color as Sailing Cals' was before he changed his tank. I wonder why O'day would have painted some of their tanks but left others as bare aluminum?

Thanks for your help and ideas everyone.

 

[jibes138]

Austenitic stainless steel is not magnetic so you can’t use that to differentiate from aluminum. If the tank is magnetic it is definitely steel. If it is not magnetic then you don’t know what it is. Aluminum has much higher electrical conductivity, that can be used to compare the two perhaps.

The tank I used is available on Amazon.com at this link. http://www.amazon.com/Moeller-Marin...1&sr=8-1&keywords=moeller+23+gallon+fuel+tank

The tank is only 12 inches tall so it will fit into the slot in the quarterberth no problem.

You also need to buy the replacement sender with the fuel return fitting. Also available through Amazon at this link. http://www.amazon.com/Moeller-Marin..._sim_sg_5?ie=UTF8&refRID=1CAFT3BTQHTJBM374PQD

Remove the sender that came with the tank and replace it with the new one. Adds 44 bucks to the cost for a total of $246 plus shipping. Replacing the sender does not require any new holes in the tank. Just 6 screws and it is sealed with a gasket. No problem at all.

Note the tank also has a cleanout cover installed so you can pump it out and clean it easily. The angled fuel fill ends up exactly where you want it to slip your fill hose on. I ended up replacing my fill hose anyway due to age. The vent fitting is vertical and also not a problem.

I have plans for the cradle I built if you want me to scan them for you if I can find them. Also DaveM had plans for his cradle but he went with an OEM type design for his new tank if I recall.

To remove the tank intact I had to remove the sheaves for the steering, you need to loosen the cables on the quadrant to remove the sheave pins. The side wall of the quarter berth is not structural, I am replacing the piece I cut out with an oak board to cover the cut and a plywood backing board. An afterthought is you could just add a piano hinge and then flip that panel up out of the way for easy access to the fuel filter and engine compartment. Either way works so your call on which item to cut. Let me know if you need any other info.

 

[njlarry]

Hey RA, have sawzall. Let me know if you need a hand. I seen folks use 6 gal portable gas tanks as temp fuel tanks to finish the season.

 

[rajhnsn]

Thanks for the offer. I have a sawzall but I may reach out once we get started. I plan to bring the boat up to Winters's for the winter and do the job there. Thinking we'll move the boat mid October.

 

[SailingCal21]

...The existing tank is not magnetic so I think that it is in fact aluminum. The tank is painted the same color as Sailing Cals' was before he changed his tank. I wonder why O'day would have painted some of their tanks but left others as bare aluminum?...

I believe that earlier versions of the tank were bare aluminum and later were painted to help prevent crevice corrosion. There are a lot of good articles online that discuss aluminum fuel tank installation, such as; http://www.yachtsurvey.com/fueltank.htm

Florida Marine Tanks was the original manufacture of Karma's tank and still (at least 8 years ago) has the drawings and can remanufacture the tank. The fabricator I spoke with says that they now use thicker gauge aluminum and are painting the tanks to abate the corrosion and pitting.

 

[rajhnsn]

So we cut the aluminum tank out yesterday. We pumped out 11 gallons of diesel about two weeks ago leaving only a few ounces of black watery fuel in the forward starboard corner that we could not reach. We used aluminum cutting wheel on a grinder for the corners and aluminum blades on a zaw saw. We were able to cut the circumference of the tank with minimal problems but were surprised to find that the baffle was holding on to the sides and lid of the tank. We cut out access areas on the front and top to reach the baffle. Once it was free the top 3 or 4 inches of the tank were removed to reveal the inside. The bottom of the tank was easily removed after a scupper hose was taken off.

Inspection of the remains did not reveal any holes that would have dumped the 6 gallons of fuel into the bilge back in August. There was never a repeat of the spill and the tank had been refilled to the half way point. The only plausible hypothesis at this point is that the lift pump was left on while we were away from the boat and it forced the fuel out of a hose connection. There was a wet area under the tank below the pick-up/return hoses. It is unlikely that the leak happened while the motor was running because air would have been sucked into the system causing the motor to run rough at the very least.

Was the tank removal and ultimate replacement for naught? I conclude not. There were two areas that showed corrosion (even thought they would likely have lasted another 30 years) and the number of other Oday 34/35's that seem to have this problem, would lead me to believe that this endeavor was/is not folley.

I will be replacing the tank with the plastic tank that Jibes used. The tank and the accessories are sitting in my Amazon shopping cart waiting for the price to stop dropping. Currently down to $216.00 plus the sender and fuel gauge.

The dimensions of the new tank are 24 X 20 X 12. The foot print of the old tank was 23 X 23. It looks like the old cradle will have to be removed a new one built. We will likely build it on site.

Here are a few picks in case you have any ideas.

 

[damauney]

RA

Nice job. You are on your way.

GoodWinds
DaveM

 

[jibes138]

So we cut the aluminum tank out yesterday. We pumped out 11 gallons of diesel about two weeks ago leaving only a few ounces of black watery fuel in the forward starboard corner that we could not reach. We used aluminum cutting wheel on a grinder for the corners and aluminum blades on a zaw saw. We were able to cut the circumference of the tank with minimal problems but were surprised to find that the baffle was holding on to the sides and lid of the tank. We cut out access areas on the front and top to reach the baffle. Once it was free the top 3 or 4 inches of the tank were removed to reveal the inside. The bottom of the tank was easily removed after a scupper hose was taken off. Inspection of the remains did not reveal any holes that would have dumped the 6 gallons of fuel into the bilge back in August. There was never a repeat of the spill and the tank had been refilled to the half way point. The only plausible hypothesis at this point is that the lift pump was left on while we were away from the boat and it forced the fuel out of a hose connection. There was a wet area under the tank below the pick-up/return hoses. It is unlikely that the leak happened while the motor was running because air would have been sucked into the system causing the motor to run rough at the very least. Was the tank removal and ultimate replacement for naught? I conclude not. There were two areas that showed corrosion (even thought they would likely have lasted another 30 years) and the number of other Oday 34/35's that seem to have this problem, would lead me to believe that this endeavor was/is not folley. I will be replacing the tank with the plastic tank that Jibes used. The tank and the accessories are sitting in my Amazon shopping cart waiting for the price to stop dropping. Currently down to $216.00 plus the sender and fuel gauge. The dimensions of the new tank are 24 X 20 X 12. The foot print of the old tank was 23 X 23. It looks like the old cradle will have to be removed a new one built. We will likely build it on site. Here are a few picks in case you have any ideas.

looks good. I'll send some pics of my cradle at earliest opportunity. I had more fuel in the bilge than the tank would create and found a split fuel line that would only leak while the electric pump ran. It was hard to find as the fuel ran along the hose and dripped down in a spot not very visible. I just replaced all hoses given the age and put in a Racor 500 ma filter. Plan on replacing all fuel line and clean the fuel pump with a new strainer while your in there.