Repair old steel fuel tank?

[cdsailor]

I dug this 47-gallon steel tank out of the bilge because it was weeping fuel. My initial plan was just to replace it, but now I’m wondering if repairing it is viable or a fool’s errand, particularly since it is forty years old and has spent its life in the bilge.

At this point, I plan to clean it up, inspect, and pressure test it to find the leak. If the leak appears repairable, I was thinking about going that route. What’s the wisdom from those of you who’ve dealt with this issue before?

Thank you!

 

[rgano]

You have the original to use as a pattern to have a new one built out of plastic. Go that route.

 

[slowgoesit]

You've already done the hard work of removing! Personally, I would not attempt to repair a 40 year old tank. It's not easy to remove and replace, I would rather have a new tank fabricated and installed. Good for another 40 years!

 

[wkearney99]

You've already done the hard work of removing! Personally, I would not attempt to repair a 40 year old tank. It's not easy to remove and replace, I would rather have a new tank fabricated and installed. Good for another 40 years!

You have the original to use as a pattern to have a new one built out of plastic. Go that route.

This. I'd seriously look into having a new one fabricated. Best start fresh. It'd be hugely annoying to have it just patched and then fail again somewhere else.

 

[JLD]

What the other folks have already posted.

Plus, if you ever decide to sell the boat, having a new (or newish) tank instead of a repaired original tank has to be a plus!

Jim

 

[koliver]

My son recently had his boat hauled for a different purpose, but had access to and replaced the fuel tank. It was a 40 yr old steel tank, hung from the cockpit floor in his 32' sailboat.
Replaced with a plastic tank, cheap, easy, reliable.
Why compromise?

 

[Pete Meisinger]

JLD, and the others are right. Replace it. But like JLD points out, any buyer "in the know" will appreciate the new tank. You may even recover the cost when you sell but for sure it will be a great selling point.

It looks like you have twin Lehmans. 47 gallons is really a pretty small tank but how did you get it out with the engines in place. The tank in your pictures really looks larger than 47 gallons. I'm guessing there are a couple more tanks in your boat of the same vintage. What are your plans for them ?

Good Luck,

pete

 

[cdsailor]

Hey Pete,

Yes, twin Lehmans in an Albin 36. She has two lateral tanks holding - reportedly - 175 gallons each that gravity feed the 47-gallon keel/centerline tank. Fuel pick ups are off the aft end of the keel/centerline tank, and each engine returns fuel to its respective lateral tank. My plan for the lateral tanks is to leave them alone until A) they become an issue, or B) we have the time and money to replace them before they're an issue. When/If that day comes, I plan to cut them out and, hopefully, fit smaller poly tanks in their place.

As far as this tank is concerned, replacement is what I had planned. I was just "testing the waters" here to see what kind of feedback I'd get. It's 100% predictable so far - and appreciated.

Thanks,

David

 

[cdsailor]

Here's how I did it: https://youtu.be/DrBST_Rz__0

 

[Comodave]

I would absolutely not try to repair the old tank, it will just leak somewhere else. Have a new tank fabricated to fit like the old one. If you go with aluminum then go extra thick so you will have a longer time before it corrodes through.

 

[MurrayM]

You have the original to use as a pattern to have a new one built out of plastic. Go that route.

Interesting stuff:

 

[Boat]

API sets standards for petroleum storage tanks. Repaired to spec, why not? Questionable repair? Never.

 

[Southern Boater]

Interesting stuff:

Agree, thanks for posting.

 

[cdsailor]

Update: I pressurized the tank once I had it home and confirmed a pinhole on the bottom of the tank. Forward end of bottom is badly corroded. Tank sat atop plywood support in the central portion of the bilge - bad design.

Verdict: Replace it.

Thanks for the input.

 

[Comodave]

If you put in a metal tank put non absorbing pads on the bottom and seal them completely to the tank so moisture can’t get between the pad and the tank.

 

[SteveK]

Curious with two 175 gal tanks, what is the advantage of a third 47 gallon tank. (besides another 47 gal).
If it were me, I would be considering not replacing it at all and tapping into the two others direct. Have you cruised the two main tanks empty and needed this to get to a fuel dock?

 

[cdsailor]

Curious with two 175 gal tanks, what is the advantage of a third 47 gallon tank. (besides another 47 gal).
If it were me, I would be considering not replacing it at all and tapping into the two others direct. Have you cruised the two main tanks empty and needed this to get to a fuel dock?

Steve,

I'm guessing it was Albin's solution to equalizing the tanks without adding a manual selector. We certainly could plumb each engine to its respective lateral tank. Eliminating the centerline tank would remove about 400 lbs from low in the boat. Given that she's a twin, losing the weight would be nice, but I'll admit I rather like the idea of the additional ballast down low. Is that weight needed for some design reason? I don't know.

 

[SteveK]

Steve,

I'm guessing it was Albin's solution to equalizing the tanks without adding a manual selector. We certainly could plumb each engine to its respective lateral tank. Eliminating the centerline tank would remove about 400 lbs from low in the boat. Given that she's a twin, losing the weight would be nice, but I'll admit I rather like the idea of the additional ballast down low. Is that weight needed for some design reason? I don't know.

Ballast usually does not change. would they design a fuel tank as ballast and not expect you to drain it. I would think it is an added bonus for a long trip, nothing more.

 

[cdsailor]

Ballast usually does not change. would they design a fuel tank as ballast and not expect you to drain it. I would think it is an added bonus for a long trip, nothing more.

Yes. This is a centerline tank that sits lower than the lateral tanks and is gravity-fed by both, meaning it is always full - unless the lateral tanks are emptied, which I suspect is highly unlikely. So though it may not qualify as ballast, practically speaking, it is. Whether it's really necessary or not, I don't know - probably not.

 

[wkearney99]

Steve,

I'm guessing it was Albin's solution to equalizing the tanks without adding a manual selector. We certainly could plumb each engine to its respective lateral tank.

The draw from engines is not typically equal between tanks, and then there's a generator. Which would typically get it's own pickup to avoid starving/being starved by engines.

There's probably as many schools of thought on fuel tank isolation/management as there are ways to connect them.

 

[Pete Meisinger]

I can't see the need for ballast or the third tank. My 36 is a single F.L. and like many Taiwan Trawlers is slightly bow heavy. I can't believe yours is bow heavy with an extra engine. 47 additional gallons of diesel are only about 400 pounds. Wouldn't you rather have the extra room for engine maintenance or maybe line your batteries up down the center and get them out of the starboard area they are in now? Or better yet how about getting rid of that little 20 gallon black water tank and install a larger one between the engines? Possibilities are endless but IMHO you don't need the third tank.

pete

Those twin F.L.s only sip about a gallon an hour each that is still almost a thousand miles range.

 

[cdsailor]

I can't see the need for ballast or the third tank. My 36 is a single F.L. and like many Taiwan Trawlers is slightly bow heavy. I can't believe yours is bow heavy with an extra engine. 47 additional gallons of diesel are only about 400 pounds. Wouldn't you rather have the extra room for engine maintenance or maybe line your batteries up down the center and get them out of the starboard area they are in now? Or better yet how about getting rid of that little 20 gallon black water tank and install a larger one between the engines? Possibilities are endless but IMHO you don't need the third tank.

pete

Those twin F.L.s only sip about a gallon an hour each that is still almost a thousand miles range.

Pete,

I'm open to possibilities. Things to think about. It's nice to have options.

 

[SteveK]

Pete beat me to it. Have plenty of fuel. These days you need more black water storage

 

[Datenight]

I pulled the tanks in the old green trawler. One was seeping the other seemed fine. They were 125 gallon in the laz, relitivly easy to get out. Plan was to use the old ones as templates. Turned out the only bad spots were on the bottom of the one. Had them sand blasted which left holes in the one that had been seeping. The bad was cut out out and replaced.

At the same time I had another inspection hatch cut and fitted to the top and added pick ups for fuel polishing. Tanks then got three coats of epoxy primer and three coats of white epoxy paint.

Total cost for sand blasting, repair and fabrication, pick ups and epoxy paint was just under $800.00. I did the removal, transport to the blaster and repair man. Paid the yard an additinal $100.00 or so to lift them back in.

Repair was well worth it in my case. The photos show before in place, after sandblasting, the holes, painted tank (both the same) and cleanouts.

At the time my wife worked for Loctite and their development lab in Rocky Hill Connecticut was very helpful with sealants. The guys there told me they offer help to anyone who calls. We are both retired now so no more connection.

Rob