Boat rebuilt...and the aluminum tank leaks. Now what?

DFremo

Recruit
Joined
Aug 5, 2012
Messages
5
Very frustrated, folks.

I started a deck rebuild on a 1982 Tomahawk 16' fiberglass boat. It turned into a full rebuild, save the transom and 120HP I/O, which were pristine.

The 20 gallon internal aluminum gas tank was gummed up, so it was removed, flushed with water and soap, then rocked with acetone and bolts, flushed again, vacuumed clean and re-installed with new hoses, sender unit, etc. New floor glassed in and the rest of the build, too.

I filled it with 10 gallons today to prep for the first voyage, and the tank leaks. It did not leak water, but slowly leaks gas. I was able to siphon all but about 1/2 gallon back out, tipped the boat way up to let the rest drain from the bilge and will scrub it clean with soap water, etc.

So this job is screwed, as it appears the tank has to be removed and repaired or replaced. But I don't have any interest in destroying my work to do so. I just want to rip around a lake for the rest of the Summer.

So, what think you folks?

Can I just pick up a portable tank and run it into my I/O minus the primer bulb? What would I need to do to make this work?

Any help is greatly appreciated.
 

jigngrub

Fleet Admiral
Joined
Mar 19, 2011
Messages
8,155
Re: Boat rebuilt...and the aluminum tank leaks. Now what?

Not a problem to run the engine off of portables.

This is the reason to have an old tank pressure tested before reinstalling.

... and the reason for installing a full access hatch when rebuilding.
 

jbcurt00

Moderator
Staff member
Joined
Oct 25, 2011
Messages
24,829
Re: Boat rebuilt...and the aluminum tank leaks. Now what?

I am unfamiliar w/ the Woodlife CopperCoat product you used on the underside of the deck, although I've used similar to treat cut ends on PT lumber. Never seen it used in a boat. Is it inert w/ aluminum? If exposed to moisture? Chemically it isn't the same as either CCA or ACQ (the tyipical PT chemicals)....

What pressure treating was used on your stringer caps? CCA kiln dried or ACQ kiln dried? Although unlikely, if ACQ treated lumber is ever exposed to moisture, it can leech chemicals that are caustic to aluminum.

As PT wood surrounds your aluminum fuel tank that leaks, you have a pretty good idea where the tank is located below deck, you have experience w/ fiberglass work, I'd suggest you 'surgically' remove the deck from stringer to stringer, bulkhead to bulkhead above the tank & replace the tank w/ a poly equivalent.

Wish you'd found us before you started the rehab. You did a great job chronicling the process on your blog. A few things might have been done differently, as Jig suggested a pressure test of the tank, could have prevented the leak.
 

DFremo

Recruit
Joined
Aug 5, 2012
Messages
5
Re: Boat rebuilt...and the aluminum tank leaks. Now what?

Good advice, gents. And much appreciated. I am already kicking myself over the pressure test, but I have to deal with the present.

I think I will run the portable for the season and surgically replace the aluminum one in the Spring.

Though I think finding a size to fit will be very hard, I know there are kits to "seal" a leaky tank, but that sounds suspicious, and why risk corrosion, again?

The pressure treated lumber is non-caustic. And the Coppercoat is a new product, also non-reactive to aluminum. Considering the old funky gas smell when I tore the boat apart, I am certain the pinhole leaks preceded the rebuild. But it sat for so many years, it was impossible to determine where exactly the smell was from.

Here's another question: There is a bow bulkhead and an aft one, but there are hairline leaks in the aft one, I discovered. I tipped the boat just to the point of touching the skeg to the floor and the gas slowly ran out the drainhole. Should I drill this out, or seal it completely when I replace the tank? If water would happen to get in there, it would sit and sit. Presumably that's how the previous one corroded, and how water got under the rest of the deck.

Last one: Should I run the portable with or without a priming bulb?

Much appreciated.
 
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