# Fuel Tank Repair



## Play'N Hooky Too (Sep 29, 2007)

This last week I removed the aluminium fuel tanks from my project boat (31' Silverton) in order to give me some more room to work in the forward compartment and to inspect/clean them out. I noticed on the bottoms of the tanks that there were a couple of small spots that were pitted to the point that it didn't look like it would be long before they would break-through. I was considering going over these with JB Weld before I put them back in and was wondering if that would be effective or if I should use something else.

Also, the tanks sitstrapped tobenches in the compartment so they are exposed on all sides except the bottom. I've noticed that when they are full they sweat pretty bad and was wondering if I shouldn't put some type of matting underneath them to prevent moisture build-up.

Thanks for any advice.


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## Breeze Fabricators (Oct 2, 2007)

Don't try to epoxy those tanks. You are trying to bond to an already oxidized surface and it will pop out when you are in rough seas and the fuel is sloshing around. Rince it out with degreaser and water and bring it to me of any other of the welder/fab guys here on the forum. The whole bottom can be replaced if it needs to be and alot cheaper than a new tank or blown up boat from fuel leaks at sea and under way.:usaflag


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## jim t (Sep 30, 2007)

On another forum I read,pitting isa common problem, especially on older boats that were held in place with foam.The commonly held solutionisto fiberglass the entire tank to waterproof it after JB Weld on the pitted area.

Jim


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## sealark (Sep 27, 2007)

JB weld will nor work because the Aluminum will expand and contract at a different rate then the JB weld and seperate. One way is if you have the room is to first clean the entire tank and wipe it with viniger and then cover the entire tank with fiberglass. If there is a leak first have it welded and then fiberglass it. I did this on a Aluminum tank in a 17' Aquasport and it lasted at least for the 5 more years I owned it.


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## Play'N Hooky Too (Sep 29, 2007)

Sounds like I definitly need to check into having them welded. 

As far as putting anything under them, upon reflection, I guess that since they have beenin the boat or 23 years and the limited amount of pitting that I'm seeing now isall that has occurred over that period, I'll probably just put them back in the way they were installed by the mfgr.Apart from the bottoms the rest of the tanks are in great shape, just dirty from 23 years of dust and grime.

Thanks for ya'll help.


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## Snagged Line (Sep 30, 2007)

Given what is at stake with a failure of a patch there is only one course of action to take and it has already been mentioned.

I am one of those people that can NEVER pull off a shortcut without having it come back and bite me in the butt at a later time.

if this was my project and I knew that the tank was compromised as describedand chose to smear bondo / jb weld/ fiberglass /undrecoaring or any other quick fix that sounded like it will prevent what I already know is gonna happen anyway, I wound just have to adjust My priorities to do the long term fix rather than have the unexpected shutdown thenite before the big fishing event or cruise of a lifetime or try to explain away the "I think I smell gas feeling" that will come up at some point in the future. ( my luck would have it start leaking abought the time I decide to sell it and I would be looking at tearing the tank out and doing all of this in order to make the boat sellable)

Hopefully whatever you decide will work out. Good luck



EDIT///Slow typing and eating a sandwich strikes again/ sounds like you have everything under control


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## Hook (Oct 2, 2007)

I would go with a new tank. Call Perry Florida to get a price. VERY reasonable.


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## johnsonbeachbum (Oct 1, 2007)

I bet the bad spots are right were the tank is touching something, like the straps. Or a dissimular metal is touching those spots?

After you have it repaired, I would entertain having the entire tank Rhino lined on the outside. It will isolate contact with everything that might cause more bad spots or wear spotsincluding moisture from sweating. And it will be a little bit insulated and corrosion will be less likely too.


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## parrothead (Oct 1, 2007)

My definition of a BAD gas tank.


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## jim t (Sep 30, 2007)

I looked into having a 75 gallon tank Rhinolined... it was almost as much as a new tank. I even told them they could hang on to the tank for a couple weeks and just use "leftover" stuff on it as they finished up a job. No dice. Maybe if you know somebody who worked there it'd be cheaper.

I'd probably fiberglass at least the bottom of the tank if it showed pitting. Couldn't hurt.

Jim


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## Play'N Hooky Too (Sep 29, 2007)

> *parrothead (1/1/2009)*My definition of a BAD gas tank.


Crap!!! Luckily mine ain't nowhere near that bad.

Actually, after scrubbing them off with somea scouring pad, it turns out that some of the areas that I thought werecorrosion were actually "mineral" deposits that, once removed, exposed solid un-affected metal underneath. These deposits must have been calcium based because the vinegar wash that Sealark suggested went to town on them. 

There was only one spot about the size of a dime on the port tank that actually had pitting and that was only about 1/16" deep on 1/4" thick aluminium. I like the rhino lining idea unless there is a good reason not to go that route. 

Thanks again for ya'lls help.


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## johnsonbeachbum (Oct 1, 2007)

Yea the Rhino lining is not cheap.

You could do the hillbilly ******* thing and smear the tank with some really sticky, thick, high temp grease or even spray it with tar that has been mixed with gasoline in order to spray it. The gasoline will evaporate and leave a tar skin behind.

It will smell for a few weeks but the tank will no longer corrode or accumulate mineral deposits.


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## X-Shark (Oct 3, 2007)

I see a LOT of stuff recommended here that is out to lunch.



Fiberglassing a tank is WRONG! The original tank in my boat had that done. Before I bought the boat. I literally ripped the glass off with gloved hands.



Installing a mat under the tank will make the problem worse. All tanks sweat in a bilge and thus is how moisture gets into your fuel also. It's the change in temp's that do it.



The way to stop corrosion on a tank is to coat it. You don't need to spend the money for Rino Lining. But you sure don't want any half ass greased up tank. 



The standard has become Coal Tar epoxy coating. Coal Tar epoxy has been used in the offshore drilling industry for a Loooooog time and proven itself VERY effective.



In this link you ill find pixs of a new tank that was coated as well as pix's of a old tank that had no sign of leaking, until the tank was pulled.



This customer just wanted to replace all the fuel hoses. I insisted that with the tank exposed this far that is was coming out of the boat for a FULL inspection. As you can see it was a good move.



Nothing wrong with a foamed in tank, as long as it's coated to prevent any moistue for contacting it. It's the noncoated tanks [the way the factory installes them] that are the problem. By the way the proper foam to use when reinstalling a tank is 4lb density. NOT 2lb density.





http://www.classicmako.com/forum/topic.asp?TOPIC_ID=11506&whichpage=1


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## sealark (Sep 27, 2007)

> *X-Shark (1/2/2009)*I see a LOT of stuff recommended here that is out to lunch.
> 
> Fiberglassing a tank is WRONG! The original tank in my boat had that done. Before I bought the boat. I literally ripped the glass off with gloved hands.
> 
> If you will note in my fiberglass recommendation I said cover the COMPLETE tank. If you do that it will work as in effect you have a sealed tank. Like I posted it worked for many years for me.


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## X-Shark (Oct 3, 2007)

I heard you loud and clear Sealark. Mine was done the same way with polyester resign and mat. Again I cut it in a spot with a razor knife and ripped it off with gloved hands.



Now with your tank buried again. How do you know it's alright? I mean it's buried.



Be careful what you trust your life to. Just because you don't smell fuel, doesn't mean much to me.



Example: No fuel was smelled from this tank, but yet you can see where it was leaking.

















































New tank installed with a Coal Tar epoxy coating.


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