Water in Fuel Tank

[Triskele]

Well...it finally happened. After four years of owning this boat, I finally mixed water into my diesel fuel tank. I was filling my water tank and instead of opening the water tank I opened the reserve fuel tank and let in about a half gallon of water before realizing I was putting it in the diesel fuel plate. The tank was about 3/4 full with diesel (approx 60-70 gallons). Any suggestions for what to do? Is there an additive or treatment I can add to the tank to deal with the water? Will it be handled by the fuel filters and removed there? Is it a small enough amount not to matter?

 

[bobk]

Well...it finally happened. After four years of owning this boat, I finally mixed water into my diesel fuel tank. I was filling my water tank and instead of opening the water tank I opened the reserve fuel tank and let in about a half gallon of water before realizing I was putting it in the diesel fuel plate. The tank was about 3/4 full with diesel (approx 60-70 gallons). Any suggestions for what to do? Is there an additive or treatment I can add to the tank to deal with the water? Will it be handled by the fuel filters and removed there? Is it a small enough amount not to matter?

Open the tank through one or more fittings and suck up the water with a dip tube. Get as much as possible. Are you using water coalessing filters?

Bobk

 

[Avenger]

DO NOT use an additive or treatment to deal with it. As Bob said, try to find a way to remove it or at least as much of it as you can. If you can't, let the filtration deal with it. If you have to let the filtration deal with it, and you will to some extent either way, be vigilant because most filtration can't handle a half gallon of water in a single dose.

 

[SEVEN]

If it were me I would go directly to the sending unit / fuel gage and pull that. Insert pump there. After sucking out as much water as possible use litmus paste applied to a stick and dip the tank to verify you have sucked out as much water as possible. Once you feel that 99.9% of the water is out start the motors and watch the filters. Drain the water as you see it at the bottom of the filters. Make sure you have a few filters on board just in case. One more thought. The longer you wait to suck the tanks out the better. This gives the water a chance to get all the way to the bottom. Good luck and take comfort in knowing this is not the first time this has happened to a boater.

 

[brico]

if your tank can be sucked dry (pulling the water which is now on the bottom of the tank) i'd be concerned, otherwise just enjoy boating. 1-2 gallons of water can never be sucked out that easily. If you suck a bit of it when running in rough weather and tanks are sloshing, your filters should take care of it.

 

[SEVEN]

Wow, wow,wow

 

[Fanfare]

Easiest if you have Racor filter/water separators and can readily see and drain the water as it is removed. My old boat came with the original DD metal spin on fuel filters with no way to check how much water was in there. Racors effectively remove the water, but you would need to observe the bowls. I have never had more than a half cup of water in there at a time. If the bowel fills up and water gets into the injector it flashes into steam and blows the injector tip off. This bit of metal then rattles around the cylinder until going out the exhaust. Try to avoid this!!

 

[Triskele]

Have done a bit of online research on this subject. Advice ranges from snake oil treatments (chemical) to pulling the tank, dumping and cleaning (not practical). Seems the correct way to do this would be to pump out as much as possible all the fuel and water into a barrel. Drop a dessicant bag into the tank to dry out all the remaining water, pour in biocide and refill with clean fuel. However, seems like a lot of work and expense. Guess if the fuel tank had been near empty at the time it became contaminated, this would be the most practical option. However, with 60 gallons of fuel and being at a marina, it may be a bigger project than I want to take on.

After all the advice, I guess my plan is to attempt to "suck" out the water and let the Racors do the rest. Options for sucking out the water...i) Diesel Tank Snake Absorber (http://b3cfuel.com/products/diesel-tank-snake-water-absorber) or ii)"snaking" a hose or dip tube to the bottom of the tank and pumping out the water (as recommended by others here). Has anyone tried or used a B3C Fuel Tank Snake? Can I use my oil changing pump to pump out the water? Can't see why it would be a problem. The problem I am not able to get my head around is that 1/2 gallon of water is about 115 cu. in. which is 4.8 (call it 5") cubed. However, the length and width of the tank is easily 36" x 24" which would imply that once settled at the bottom, a 1/2 gallon of water would be equivalent to less than a 1/2 inch (1/6" to be exact) of water. My question is...Is it realistic to think that I will be able to suck out less than 1/2 inch of water using a dip tube? I guess the point is any water sucked out is a good thing. Isn't this really just something the Racors can handle over time?

So the issue with leaving water in the bottom of the tank is algae bloom. Solution...biocide! Should be sufficient? Right?

Seems the concern with leaving the seperation to the Racor is the risk of water slipping by and getting into the injectors causing them to foul from steam and leaving shrapenel in the cylinders. All not good...(then I will really be wishing I had drained and dried the tank). However, I'm not convinced this a serious concern for my situation. Remember...this is an ancient (1981 model) Detroit Diesel 671, not a highly tuned Cummins or Cat where tolerances are probably much less forgiving). These motors have over 3000 hours and 35 years of life. Surely, during that time there has been some bad fuel and water mixed into the system (if not from condensation alone). Obviously the Racors do there job. It is also my suspicion that it would take a lot of fuel abuse (contaminants/water) over many hours of operation to blow off the tips of the injectors. However, to confirm, I plan to contact injector manufacturers for some tech support on this issue and will report back.

I have attached some photos of my Racors. Says Fuel/Water Seperator on the label so presume it means these are the spinning type. Don't know if the filters are coalescing, but if spinners presume so.

Since I have twin diesel, my plan is to only run the contaminated fuel from the reserve tank through one motor (thus not risking two) and return to the reserve until it has all been consumed or at least down to enough where I can siphon off the rest and not care. However, I will only do this after I have made an attempt to first drain (suck out) some of the water that should have settled to the bottom. How much time should I give it to settle? Thinking maybe a couple of days.

So that's the plan...suck, run, and drain filters. Seems consistent with most of the advice I have received here, but would welcome any further input or concerns with this approach.

Thank you all for your responses and helpful advice!

 

[Triskele]

Easiest if you have Racor filter/water separators and can readily see and drain the water as it is removed. My old boat came with the original DD metal spin on fuel filters with no way to check how much water was in there. Racors effectively remove the water, but you would need to observe the bowls. I have never had more than a half cup of water in there at a time. If the bowel fills up and water gets into the injector it flashes into steam and blows the injector tip off. This bit of metal then rattles around the cylinder until going out the exhaust. Try to avoid this!!

Jim thanks for thoughts. Agree...believe Racors should handle it after attempting to syphon off what I can (water) from the bottom of the tank.

 

[Triskele]

DO NOT use an additive or treatment to deal with it. As Bob said, try to find a way to remove it or at least as much of it as you can. If you can't, let the filtration deal with it. If you have to let the filtration deal with it, and you will to some extent either way, be vigilant because most filtration can't handle a half gallon of water in a single dose.

Thank You! Will keep an eye on it.

 

[Triskele]

If it were me I would go directly to the sending unit / fuel gage and pull that. Insert pump there. After sucking out as much water as possible use litmus paste applied to a stick and dip the tank to verify you have sucked out as much water as possible. Once you feel that 99.9% of the water is out start the motors and watch the filters. Drain the water as you see it at the bottom of the filters. Make sure you have a few filters on board just in case. One more thought. The longer you wait to suck the tanks out the better. This gives the water a chance to get all the way to the bottom. Good luck and take comfort in knowing this is not the first time this has happened to a boater.

Have attached a photo of what I believe to be my fuel guage sender. This is what you are suggesting I remove to put a dip tube into the tank. Correct? Just want to confirm. Thanks for your advice and help.

 

[Triskele]

Open the tank through one or more fittings and suck up the water with a dip tube. Get as much as possible. Are you using water coalessing filters?

Bobk

Bob...thanks for your comments and advice!

 

[Cricket]

Probably a good idea to see what you have in the bottom of the tank anyway.

 

[bobk]

Bob...thanks for your comments and advice!

OK, so where are the photos? I ask because given the calculations you provided, it might be tough to get that thin layer of water up. On the other hand, the dark color of your Racor bowls suggest you have had water and microbes growing in there for some time, so there may be more than you expect. So that leads to two other thoughts.

1, If there is a fitting, bolt or something else you can remove close to a corner of the tank, shift weight to that side so the water will be deeper there and easier to retrieve. Maybe drill a hole in an appropriate spot to gain access and then seal it back up.

2, Attach a curved piece of clear PVC tubing to the bottom of your suction pipe. Plug the end of the tubing and drill a bunch of small holes in the curve in the area that will be closest to where the tube will touch the bottom of the tank. Using this you can sweep around and perhaps get more of the water. Don't worry about taking up too much fuel. Put it in a clean jug and it will separate and you can decant off the clean fuel layer right back to the tank.

Fuel and water will separate fairly quickly. I'd say hours, not days unless it has emulsified.

Good luck,

Bobk

 

[Triskele]

OK, so where are the photos? I ask because given the calculations you provided, it might be tough to get that thin layer of water up. On the other hand, the dark color of your Racor bowls suggest you have had water and microbes growing in there for some time, so there may be more than you expect. So that leads to two other thoughts.

1, If there is a fitting, bolt or something else you can remove close to a corner of the tank, shift weight to that side so the water will be deeper there and easier to retrieve. Maybe drill a hole in an appropriate spot to gain access and then seal it back up.

2, Attach a curved piece of clear PVC tubing to the bottom of your suction pipe. Plug the end of the tubing and drill a bunch of small holes in the curve in the area that will be closest to where the tube will touch the bottom of the tank. Using this you can sweep around and perhaps get more of the water. Don't worry about taking up too much fuel. Put it in a clean jug and it will separate and you can decant off the clean fuel layer right back to the tank.

Fuel and water will separate fairly quickly. I'd say hours, not days unless it has emulsified.

Good luck,
Bobk

Hi Bob...Finally had a chance to report back on what I did about dealing with the water in the tank. Thanks again for all your advice and help (as well as the others on this forum). It turns out that the depth of my reserve tank is only 8" and I probably had only about 6" of fuel. I made a sucking tool out of a fuel tank dip rod and a fuel line with a bulb for priming gas motors. It worked great. Pumped out about a gallon of fluid from the bottom. Didn't see any water after allowing to settle overnight. Cleaned my fuel filter bowls (which they needed, and as you so aptly noted). About a 1/4" of gunk and algae on the bottom. Added an extra ounce or two of biocide to the tank. Installed new filters. Primed filters with new fuel. Ran motors for about half hour with no noticeable difference in operation and performance. In fact, they seemed to run and sound better. Long story short, I think the water in the fuel issue (or lack there of, as I honestly don't think so much probably got into the tank) has been resolved. But, I learned my lesson. Have painted the fuel plate cap red and the water plate cap blue. Hopefully that will prevent me from making that mistake again should I not be paying better attention to what I am doing.

 

[bobk]

Hi Bob...Finally had a chance to report back on what I did about dealing with the water in the tank. Thanks again for all your advice and help (as well as the others on this forum). It turns out that the depth of my reserve tank is only 8" and I probably had only about 6" of fuel. I made a sucking tool out of a fuel tank dip rod and a fuel line with a bulb for priming gas motors. It worked great. Pumped out about a gallon of fluid from the bottom. Didn't see any water after allowing to settle overnight. Cleaned my fuel filter bowls (which they needed, and as you so aptly noted). About a 1/4" of gunk and algae on the bottom. Added an extra ounce or two of biocide to the tank. Installed new filters. Primed filters with new fuel. Ran motors for about half hour with no noticeable difference in operation and performance. In fact, they seemed to run and sound better. Long story short, I think the water in the fuel issue (or lack there of, as I honestly don't think so much probably got into the tank) has been resolved. But, I learned my lesson. Have painted the fuel plate cap red and the water plate cap blue. Hopefully that will prevent me from making that mistake again should I not be paying better attention to what I am doing.

The next test will be to run in a sea way. Bring extra filters just in case.

Bobk

 

[SEVEN]

You didn't need to paint the caps, you only need to do that once to learn the most valuable lesson. I did it one with gas engines but never again. Slow slower then slowest movements when filling fluids.

 

[Fanfare]

Now just be careful not to mix the caps up!