Throwing my stainless steel holding tank overboard!

At the risk of annoying a number of purists, i thought I'd post an update. I found a very generous youn couple that offered to hel me remove my leaky tank. I don't get my staples out from my liver cancer surgery for two more days still so I'm not of much help.. James was able to get my battery bank disconnected and out of the way and he waa able to get the board the bank was on out as well. I ordered a replacement tank with the identical measurements, $585 with shipping and taxes. Today he tried to pull out the old tank and he could not get it to budge! All hoses and fittings removed, she's nestled between two massive stringers and my twin ford lehmans... Ww boght a big crowbar to try to pry it loose and nothing. James is not a small guy and he wrestled with it for a good hour and no progress. No apparent brackets or braces or glues or sealants anywhere. Just wiil not budge in any direction.. Tomorrow we're trying a come along suspended from a big beam spanning the engine hatches.. Any clues? 1981 Formosa 42' trawler...

Vacuum implode it ?

How?

With boiling water? Seal it up then douse it with cold water? I'm not sure we can seal it that well but I like the suggestion.. Oversized stoppers would probably work...

Sawsall

swampu said:

Sawsall

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I second the demo saw. Or, an angle grinder with a thin metal cutting abrasive blade. There may be some 5200 involved here.

That's what we were wondering. I think its the original 1981 Taiwan tank. Did they have 5200 back then? probably some ancient Chinese ultra glue...

Contrary to what some may think, 5200 is not the only sealant/adhesive ever made. There's a good chance the original tank was installed with an adhesive or foam.

If you have a way to apply upward pressure on it (the come along), crank on it as hard as you can and walk away for a day. You may find it has loosened. If so, repeat until you can break it loose.

Before you get too aggressive, anything in it?

No. Havent put anything in

...in it for a month. Pump out boat has pumped it out each week so I doubt there's much in there.. Why??

Put a beam across the overhead and then a come-along rigged to tank, hook through a hole, whatever. Pull hard. Probably foamed in.

New tank may need to be ordered a touch smaller as if fit is that tight, new one might be a quarter inch bigger and not fit. Don't order new one til old one is out and you can get good measurements.

Cut the top out, remove baffles (if any) and have a plastic tank constructed just to fit inside. You have a great foundation and a second barrier against any leakage. All holding tank connections should be in the top anyway.

Bigfish said:

...in it for a month. Pump out boat has pumped it out each week so I doubt there's much in there.. Why??

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There's always something in there. Wear protection!

Roger Long said:

Cut the top out, remove baffles (if any) and have a plastic tank constructed just to fit inside. You have a great foundation and a second barrier against any leakage. All holding tank connections should be in the top anyway.

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Roger,

I like that idea, and also would not be hard to cut out the sides, too. I'd suspect a plasma cutter would cut that up like butter.

There also might be a thought in using some heat on the bottom, after removing the sides.

Bigfish said:

How?

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vacuum pump for ac systems

HOLLYWOOD

If tank leaks, vac pump won't work.

Too late. New tank is exact same measurements and waiting patiently. There is an inch gap between existing tank and stringers on each side. No foam to be seen anywhere. Old tank has only one fitting on the top and that's for the tank full warning gauge. I decided to plum the new tank the same way the old one was. Worked fine for 36 years...

I would make sure I purge the tank well with air, to gas free it before any heat/spark destruction, sawsall the sides down for access, demuck, then try good heat gun/ torch to loosen adhesive, brute force could leave a mess depending on what gives way, let us know, good luck!

Yeah, get it all out. That thing is a tetanus magnet in the bilge with sharp edges.