Need Guidance on a 30 Year Old Fuel Tank - 24'Skipjack Fisherman

[peter7883]

I own a 24' Skipjack Fisherman that I purchased new in 1991. I have seen a few topics on old fuel tank failures and decided to take a closer look at mine after removing most of the fuel from the tank. The boat has always been trailered and resides in a low humidity environment. There is a fuel water separator filter installed on the boat that I replace every season. I also use a fuel additive regularly to break down any water that gets into the fuel. The first thing I noticed after removing the access panel to the tank is that it is foamed in which is not usually done any more. The tank was built by Berry's in Costa Mesa, CA. and it looks like it was a good installation. The sticker on the tank says it is 112 gallons. Surprisingly, the foam is rock hard and there is no sign of any water intrusion of fuel odor. I then removed the fuel level sending unit to get a better look inside the tank. Unfortunately, you cannot see all the way back to the fuel pickup tube due to the baffles inside the tank. But I was able to get a good look at most of the tank and get a few pics as well. There are some small pieces/debris that were probably introduced with the gas over the years but overall I thought the tank looks like it is in descent shape. I attached some photos and would like your opinions on what you would do if this was your boat? Does this tank have more life in its current condition or what are the next steps that I should consider? I appreciate all you input.

Thanks,

Peter

 

[Hismosa]

Looks brand new to me. Keep on trucking

 

[Windy Bay]

If it were my boat-If it's not broke don't fix it!!!! It looks really good. Looks like the foam has always been dry, which is the key. When you put the hatch down make sure to seal it with 5200 caulking.

 

[Fishbones]

You went this far... I would pull it to check corrosion on the bottom and sides just for piece of mind... then paint it before reinstalling. Use Pool Noodles for floatation around the tank

 

[SkipTown]

Looks beautiful but unfortunately, the area that gets the corrosion is the place you can't see through the baffles. If any water was ever in the tank (and they all have a little), it sits in the lowest corners of the tank which is pretty close to the fuel pickups. Call Berry Tank and discuss - they built me a new one and had plenty honest insight as to what I'd find on an old tank after 20-plus years.

Can you get a bore-scope (try a cheap eBay borescope that connects to your mobile device with a camera app) down through the fuel pickup tubes? If you see no corrosion then hallelujah. But if you see a little, you have to decide how deep the rust has gone through and how much longer it would last until you get a fuel drip in the bilge.

I tried it all - polishing the fuel, draining it dry, and even thinking I'd find some miracle goop to maybe seal from the inside (doesn't work) but all the experts told me to replace the tank. And I did.

 

[dctrjayyy]

What type of boat owner are you? It looks brand new but is past it's service life. I'd leave it. If you're the type that wants everything perfect, God bless you, pull it. At that point, the hard work is done and I'd just replace it with new. Sell the old to recoup some of the cost

 

[Crowman]

You could alway's pressure test it but I would call the manufacturer and let him tell you what you should do. You could if you decide to keep it installed get a turkey baster with a length of clear tubing and suck up those pieces of the bottom.

 

[peter7883]

Looks beautiful but unfortunately, the area that gets the corrosion is the place you can't see through the baffles. If any water was ever in the tank (and they all have a little), it sits in the lowest corners of the tank which is pretty close to the fuel pickups. Call Berry Tank and discuss - they built me a new one and had plenty honest insight as to what I'd find on an old tank after 20-plus years.

Can you get a bore-scope (try a cheap eBay borescope that connects to your mobile device with a camera app) down through the fuel pickup tubes? If you see no corrosion then hallelujah. But if you see a little, you have to decide how deep the rust has gone through and how much longer it would last until you get a fuel drip in the bilge.

I tried it all - polishing the fuel, draining it dry, and even thinking I'd find some miracle goop to maybe seal from the inside (doesn't work) but all the experts told me to replace the tank. And I did.

I decided to take your advice Mike, and perform one additional step to inspect it. I am going to remove the fuel pick up tube and use a borescope to get a better look as you suggested. This should be sufficient to make a more definitive decision on the true condition of the tank. If I determine I have to pull the tank out to inspect it more throughly, I would just replace it at that point. More to come. I need to go guy a borescope now. Thanks, Peter

 

[peter7883]

You could alway's pressure test it but I would call the manufacturer and let him tell you what you should do. You could if you decide to keep it installed get a turkey baster with a length of clear tubing and suck up those pieces of the bottom.

I will definitely clean it out if I determine to keep it and not replace it. I will also talk to the manufacturer after I borescope it and get their opinion as well. Thanks, Peter

 

[MYNomad]

If it were mine, I would do a pressure test, every year. I would also install a fuel sniffer -- that way, the first time a molecule of gasoline leaks out, you will get a warning. But at that point, you have an immediate problem.

 

[peter7883]

If it were mine, I would do a pressure test, every year. I would also install a fuel sniffer -- that way, the first time a molecule of gasoline leaks out, you will get a warning. But at that point, you have an immediate problem.

I think you are correct, I intend to call the manufacturer today and get their advice on how to perform the pressure test. Thanks, Peter

 

[MYNomad]

I think you are correct, I intend to call the manufacturer today and get their advice on how to perform the pressure test. Thanks, Peter

As along as you are talking to them, you should ask about whether corrosion typically / often / occasionally / never starts outside the tank and works its way in, in which event inspecting the top and inside may give you a false sense of security.

 

[peter7883]

As along as you are talking to them, you should ask about whether corrosion typically / often / occasionally / never starts outside the tank and works its way in, in which event inspecting the top and inside may give you a false sense of security.

I talked to the tank manufacturer. They said there is probably some water underneath the bottom of the tank towards the back that you cannot see and is the most typical place where corrosion starts. They did say a pressure test is a good idea but can only prove the tank is good at that moment without any indication of how long it could last. After this discussion with them, I think I will take one additional step before making any firm decision to move forward with a tank replacement or not. I intend to remove some of the foam at the back of the tank all the way down to the hull bottom and see if there is any moisture at the "V" bottom. If it is still dry there, the pressure test and visual borescope looks good I'll probably call it good and check it more often for any signs of deterioration. More to come.

 

[peter7883]

I started to remove the foam at the back of the tank at the suggestion of the manufacturer and as expected about half way down I could see evidence of corrosion (white powder) on the surface of the tank. it got worst the farther down I went. I removed all the foam from the rear of the tank and there was definitely some moisture down there. No standing water but enough to raise concerns, not so much on the back side of the tank that I could see, which may or may not be bad enough to replace the tank. But the concern is on the bottom that I cannot see without removing the tank. So I made the decision to remove it and replace it regardless of how it looks when I get it out. I'm not putting a 30 year old tank back in when most of the the effort (cost) is the labor to remove the tank. I'll post some pictures of the condition after I get it out. I'll probably get a new one from Berry's unless someone has any suggestions of someone local to San Diego that builds thanks. Thanks, Peter

 

[Fishbones]

I was very pleased with my tank....

American Tanks

We are a welding shop specializing in marine grade tank fabrication and installation. Our fabrication facility is located in La Mesa, California. Our convenient central location allows us to cater to the local harbors in San Diego and Marina Del Rey. We are available to create custom tanks...

americantanks.net

 

[peter7883]

I started to remove the foam at the back of the tank at the suggestion of the manufacturer and as expected about half way down I could see evidence of corrosion (white powder) on the surface of the tank. it got worst the farther down I went. I removed all the foam from the rear of the tank and there was definitely some moisture down there. No standing water but enough to raise concerns, not so much on the back side of the tank that I could see, which may or may not be bad enough to replace the tank. But the concern is on the bottom that I cannot see without removing the tank. So I made the decision to remove it and replace it regardless of how it looks when I get it out. I'm not putting a 30 year old tank back in when most of the the effort (cost) is the labor to remove the tank. I'll post some pictures of the condition after I get it out. I'll probably get a new one from Berry's unless someone has any suggestions of someone local to San Diego that builds thanks. Thanks, Pete

The tank is out and there is corrosion on the bottom half on all sides and the entire bottom. Corrosion varied from medium to heavy but it was not yet leaking. Who knows how much longer it would have lasted. I am now looking to get a new tank built.

 

[tunacraze]

As said above, American Tanks.

 

[Fishbones]

Good call on pulling it out

 

[peter7883]

Here are some pics of the corrosion on the tank after a little clean up. It was more than 75% corroded through in a few areas. I took the old tank to American Tanks and they are now building me a new one.

 

[tunacraze]

Good decision. Glad you caught it when you did.

 

[peter7883]

Now that the new tank is being built I turned my attention on how the water intrusion occurred in the first place. After removing all the old foam around the tank it was clear that the majority of the water intrusion occurred through two cutouts on the right and left stringers that I believe do not belong there. The water goes through the cutouts to the sides and underneath the tank all the way back to the rear bulkhead in front of the engine. Unfortunately, this includes all the foam underneath the fish box as well. I intend to fill the cutouts and seal the area to avert any water intrusion occurring from this area in the future. The next project is to remove the fish box along with all the foam around it and underneath it as is likely to be more soaked since it is further back in the cavity.

 

[jayyyy]

30 years is a great run for a boat's fuel tank. I'd love to get 30 out of mine.

 

[mogambosquid]

You made the right move. Give the new tank a couple of coats of coal tar epoxy and install without any foam and it should last even longer than the original.

 

[aguachico]

nothing wrong with being proactive.

 

[Albiebac]

The tank is out and there is corrosion on the bottom half on all sides and the entire bottom. Corrosion varied from medium to heavy but it was not yet leaking. Who knows how much longer it would have lasted. I am now looking to get a new tank built.

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Wow, I'm impressed with your extraction of the tank. I never seen anyone get it out so cleanly with the foam still intact. How did you do it? I'm in the same boat. (pun intended).