Anyone opened an inspection cover for a fuel tank?

We are under contract with a 1987 Marine Trader 47 with original tanks. The boat hasn’t left the slip in a couple of years. Right now the owner is having it brought back to sea worthy condition. The mechanic took it for a sea trial but clogged the injectors because they ran it before polishing the fuel. Those are being sent out for cleaning.

So the fuel guy will be polishing the fuel hopefully this week. This boat has two 300 gallon tanks with large inspection ports with a dozen bolts each. Not only do I want the fuel polished but I want someone to open those ports and look inside to make sure in the inside of the tanks are clean. I’ve heard stories of fuel being cleaned but it still leaves all the crap that was growing on the sides of the tank.

The problem is this isn’t my boat yet and the owners are paying for repairs so far. Is there any risk of opening those ports?

Just wanted to ask for opinions here first.

Thanks
Steve

Certainly would want to pump the fuel out before opening the ports.

Unlikely the injectors were clogged. Should be atleast 2 filters before them. Probably a clogged filter.

Ted

Yes, step 1 would definitely be to make sure the fuel level is below the ports.

The report I heard is they were blowing a lot of black smoke and wouldn’t make rated RPM

We had 2-350 gallon tanks on Hobo with similar inspection ports. No problem opening them up. I did replace the gaskets not wanting to trust 25 plus year old compressed ones.

I think you’d be smart to have them opened up. Hobo’s fuel had been “polished” previously before this picture this picture was taken.

Steve91T said:

Yes, step 1 would definitely be to make sure the fuel level is below the ports.

The report I heard is they were blowing a lot of black smoke and wouldn’t make rated RPM

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I could be wrong, but didn't think black smoke was from a fuel restriction. Is the bottom and running gear (props etc) clean. Fouled props, plenty of fuel and lack of air from lost rpm might generate black smoke. You would be amazed at how little growth it takes on props to lose rated rpm.

Ted

On a 30 year old boat you're almost guaranteed to find a layer of muck on the bottom of the tanks. It would be worth opening and cleaning. One warning though. When I cleaned mine it started leaking. The heavy layer of gunk was all that was sealing the corroded bottom of the tank.

Good thing the owners are paying. Smells like an Easter egg hunt. Make sure they don’t leak before you accept. Meaning full tanks on closing. You may have to pay for the fillup. Changing the in service Racor should have told the story. Any diesel mechanic would know that before condemning the fuel tanks.
Bottom growth needs to be ruled out.
Black smoke is usually air restrictions or overload.
You are having a survey correct?

AusCan said:

On a 30 year old boat you're almost guaranteed to find a layer of muck on the bottom of the tanks. It would be worth opening and cleaning. One warning though. When I cleaned mine it started leaking. The heavy layer of gunk was all that was sealing the corroded bottom of the tank.

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Well that’s another thing that I’m worried about. Kinda want to figure that out before it’s mine, but I feel the owners aren’t going to allow cleaning for that reason

Black smoke can also be injectors. Gunk in the tank shouldn't get there through the filters, but an old boat sitting for 4 years, cleaning the injectors probably should be done, black smoke or not.

Not running for 4 years? Better get it at a darn good price.

I just noticed that the overflow tank should be mounted higher than the reservoir to avoid air in the line. Just by that picture alone, unless you are planning to do a lot of the work yourself in the next year or so, run away.

It’s been used as a floating condo for about 2 years. We are under contract for $80k but the owners have to get it to sea worthy condition, which they are. Engines have no blow by, turbos have normal amount of shaft play. The fuel tanks are my biggest concern. Had a guy on the docks tell me their beautiful 46 Jeff sat as well. They had the fuel polished and a few hours up the river it started clogging fuel filters. 6 months of changing fuel filters every few hours and it’s finally clean. I’m not doing that.

What make / model engines?

Ted

O C Diver said:

Certainly would want to pump the fuel out before opening the ports.

Unlikely the injectors were clogged. Should be atleast 2 filters before them. Probably a clogged filter.

Ted

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That was my thought as well. If there is a clogged injector, then the filtering system is inadequate.

Does it make sense to drop a small flexible camera down the filler tube to look around the tank?

Max Simmons said:

Does it make sense to drop a small flexible camera down the filler tube to look around the tank?

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Borescopes are inexpensive these days. Should be part of any tool box.
Put a stick down the filler tube to make sure there are no baffles in the way.
You may also be able to unscrew the fitting for the return line. Should be big enough dia for borescope.

Max Simmons said:

Does it make sense to drop a small flexible camera down the filler tube to look around the tank?

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Waterproof cable camera.


https://www.amazon.com/Depstech-Sem...all+camera&dpPl=1&dpID=41spDay-HGL&ref=plSrch

Ted

Engines are Lehman’s. 190 hp I believe. Turbo diesels.

Here’s the response from the broker when I asked about cleaning the tanks.

I feel much better about it.


Hi Steve,
Yes that is the plan. No point in cleaning the fuel without cleaning the tanks..
The guy who cleans the tanks has a wand the shoots pressurized fuel into the tanks through the inspection ports...
He should be able to reach most of the inside of the tanks, then he puts an additive in the fuel that cleans anything that might be remaining.
I think the additive is called Technol. I’ve been using it for years.. seems to be a good product..

Steve91T said:

Here’s the response from the broker when I asked about cleaning the tanks.

I feel much better about it.


Hi Steve,
Yes that is the plan. No point in cleaning the fuel without cleaning the tanks..
The guy who cleans the tanks has a wand the shoots pressurized fuel into the tanks through the inspection ports...
He should be able to reach most of the inside of the tanks, then he puts an additive in the fuel that cleans anything that might be remaining.
I think the additive is called Technol. I’ve been using it for years.. seems to be a good product..

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That sounds very good! I would ask about looking in the tanks while they were open.

I would want to know what the additive is and what exactly it's supposed to do. This isn't magic where the chemical bonds, turns the remaining stuff to a gas that goes out the tank vent. Clearly whatever it does will go out through your fuel system. Should you be expecting to do a number of filter changes in the near future?

Ted

O C Diver said:

That sounds very good! I would ask about looking in the tanks while they were open.

I would want to know what the additive is and what exactly it's supposed to do. This isn't magic where the chemical bonds, turns the remaining stuff to a gas that goes out the tank vent. Clearly whatever it does will go out through your fuel system. Should you be expecting to do a number of filter changes in the near future?

Ted

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No I think he cleans the inside of the tanks then filters all the junk out using an external system. But I’m sure there will still be some junk that makes it to the filters for a while.

Beware of tank cleaning. when I purchased my Jefferson, 20 + year old tanks. ,had fuel polished, lots of stuff from that. suggested tank cleaning. Did that and more stuff,curd, sediment etc. OK clean tanks ,fill with fuel and within 3 weeks found fuel leak at bottom of tank,luckly welder was able to repair. Refill and soon another leak that was not repairable without removing tank, so needed to replace tanks, Did it myself as estimates were very high as folks wanted , to remove engines, cut holes in sides and some had no idea as to how they would do repair. Both tanks made for under $5,000.00, and help/ labor from those that I give diesel to . Took about two weeks as I worked on it after work and had a lot done before I got to the yard. Be very careful and look into tanks before cleaning and see if there is a lot of rust blisters,etc on tank. I believe that the high pressure cleaning blasted off scabs of rust and that allowed fuel to come thru. Not something that I want to do again.But its done for the next owner as my Jefferson is now for sale ..

Deckape said:

Beware of tank cleaning. when I purchased my Jefferson, 20 + year old tanks. ,had fuel polished, lots of stuff from that. suggested tank cleaning. Did that and more stuff,curd, sediment etc. OK clean tanks ,fill with fuel and within 3 weeks found fuel leak at bottom of tank,luckly welder was able to repair. Refill and soon another leak that was not repairable without removing tank, so needed to replace tanks, Did it myself as estimates were very high as folks wanted , to remove engines, cut holes in sides and some had no idea as to how they would do repair. Both tanks made for under $5,000.00, and help/ labor from those that I give diesel to . Took about two weeks as I worked on it after work and had a lot done before I got to the yard. Be very careful and look into tanks before cleaning and see if there is a lot of rust blisters,etc on tank. I believe that the high pressure cleaning blasted off scabs of rust and that allowed fuel to come thru. Not something that I want to do again.But its done for the next owner as my Jefferson is now for sale ..

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I know, this scares me. But I don’t see any other choice. And honestly, I’m hoping that if these tanks are so far gone that just a cleaning will cause them to leak, I hope to discover that before we buy it. I’m going to have the tanks completely topped off as well, to again check for leaks.

My plan is to eventually install bladders so I don’t have to worry old tanks that might start leaking at any moment.

Have a link for your Jeff?

When I bought my boat in Daytona.FL I have fuel polished and tank clean to make home in Green Cove Springs. The fuel polishing guy could not vacuum the tank as there was no inspection port. I have single 230G fiberglass tank build into bow. When I got home, I cut inspection port and had the fuel polish again and vacuum. I use the opening hole for sender unit fuel gauge. My previous MT has steel tanks and were not leaking, but I was on the edge all times as the tanks were old and could give up any time. I do not like metal tanks.

Greetings,
Mr. 91. Bladders? I think some here on TF have successfully coated their tanks with some sort of sealant. Since you already will have inspection ports, applying such a material might be a solution...

RT Firefly said:

Greetings,
Mr. 91. Bladders? I think some here on TF have successfully coated their tanks with some sort of sealant. Since you already will have inspection ports, applying such a material might be a solution...

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The material maybe Flamemaster 3204. It was developed or modified for the aircraft industry. I used it but only as a preventive measure. If you search the archives, there are a couple of posts/threads where it was used successfully on leaking tanks.

http://flamemaster.com/wp-content/uploads/2014/07/CS3204-rev-01-07.pdf

Maybe I should have them coat the tank with that stuff while they are cleaning them.

Steve91T said:

Maybe I should have them coat the tank with that stuff while they are cleaning them.

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As I understand this situation, the seller is getting the boat seaworthy for sale. They won’t want to spend additional money other than what is needed to get the engine running. Cleaning the tanks is one thing, but upgrading them is something else entirely unless they demonstrate an actual leak.

dhays said:

As I understand this situation, the seller is getting the boat seaworthy for sale. They won’t want to spend additional money other than what is needed to get the engine running. Cleaning the tanks is one thing, but upgrading them is something else entirely unless they demonstrate an actual leak.

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Yeah I know l....but I may spend the money to have them done. They pay for the cleaning and while the tanks are opened up I pay to have them sprayed. It then again, that’s a bit of a gamble since it’s not even mine yet. I just don’t want to have them start leaking 2 weeks down the road.

Putting money into a boat that you're not 100 percent on is a serious risk. Kind of makes it hard to walk away if something else is a no-go. Personally I would not do it.

Be wary of this boat! You are in for a rough time if the tanks are in bad shape. From personal experience I can tell you that if there is enough crud in the tanks the Racors WILL fail and pass the crud to the block mounted filters. Even with fresh filter elements. Once the crud is in the block mounted filters they too will fail and gunk up the works. The engines are now running very poorly and awaiting service. A shame, very low hours John Deeres.

The stuff in the 5 gal white bucket is what came out of the block mounted primary filter when I dumped it into the bucket, that's crud and water mixed. The stuff in the plastic water bottle is the first draining of the Racor bowl. The Racor bowl is self explanatory. I no longer trust Racors.

For those who are curious this wasn't my boat, it was a delivery. About 18 hrs from the dock we slowed for heavy weather. At about 33 hrs from the dock the John Deere 4045T engine panels reported water in the fuel. There were no vacuum gauges installed on the Racors to indicate their status. 2.5 hrs of struggling with Racors and block mounted filters later we limped into port at low speed. We cleaned everything as well as we could, sea trials, lots of spare filters and off we went again. For the remainder of the delivery in sloppy weather the Racors were drained every hour, every 3 hrs in good weather. The block mounted primaries were drained twice a day. The block mounted primaries showed no more crud but did show small amounts of water.

The owner had an offer on the boat but is now facing considerable expense getting it ready for sale. The tanks are original 1981 steel tanks. The seller has decided to accept a lower offer in lieu of opening and cleaning the tanks. I wish the buyer luck.