Fuel tank replacement ?'s and deck replacement

Hello everyone.
I started a thread here a while back, and never kept up with it. I am working slowly on removing my fuel tank as the baffles are shot, the one I can see through the sending unit hole looks like a brown carpet, and all its parts kept clogging my intake. Anyways they tank itself is made of 16 gauge SS and looks in great shape. Is it possible to have the top cut off, baffles replace, and top put back on? If so, anybody know where I can have that done. I want the tank to be USCG certified and know there are testings that must be done to a tank to make sure it is considered safe, so a shop that does that is what I'm looking for. Also, I would like to know of some places that make fuel tanks. If I replace with new tank, I will probably go with alum due to financial reasons. I live in Long Beach, CA. The tank is 140 gallons. It was made by IMCO. I'll work on pictures soon. Just trying to start lining everything up. If I have to have it re-made, I may consider making it slightly larger to get an extra 10-20 gallons, but I need to do calculations for that.
Thanks for any help, I know there is tons of info here.

Grady

Re: Fuel tank replacement ?'s and deck replacement

Check these guys out...

Marine Fuel Tanks, Marine Holding Tanks and Marine Water Storage Tanks by Custom Marine Tanks LLC

Re: Fuel tank replacement ?'s and deck replacement

I Googled my way to a couple of local marine tank fabricators when I needed a new tank a couple of years ago. Got prices from both and used that to negotiate a final price from the most local guy.

Be careful about going with a bigger tank . . . Make sure it will fit with room to spare. It is easier to go slightly smaller when doing a replacement tank.

Re: Fuel tank replacement ?'s and deck replacement

Thanks for the help. How much room should there be to spare and why? Is it so the tank can bulge? The old tank was in foam. What you your opinions on foam vs. no foam? I'm considering no foam because when I pulled the old tank out, under the tank, all the foam that was there was soaked in water. If the tank had been aluminum, it would have rusted away years ago I would think. So, by going without foam, I know I have a few inches to work with height and length wise. Width is fine where it is as in only had about an 1"-1.5" on each side, I don't want to get any tighter than that.

Re: Fuel tank replacement ?'s and deck replacement

I think this will be an interesting read for you...


How to Install an Aluminum Fuel Tank : Boats, Yachts - Maintenance Repair and Troubleshooting

Re: Fuel tank replacement ?'s and deck replacement

yknotgo said:

Thanks for the help. How much room should there be to spare and why? Is it so the tank can bulge? The old tank was in foam. What you your opinions on foam vs. no foam? I'm considering no foam because when I pulled the old tank out, under the tank, all the foam that was there was soaked in water. If the tank had been aluminum, it would have rusted away years ago I would think. So, by going without foam, I know I have a few inches to work with height and length wise. Width is fine where it is as in only had about an 1"-1.5" on each side, I don't want to get any tighter than that.

Click to expand...

Keep in mind that the builder of the boat planned the structural strength of the hull with the method of fuel tank installation in mind. As the tank becomes larger, the installation method becomes a more important factor. I believe you mentioned a 140 gallon tank (?) So, with full fuel, it will weigh roughly 980 lbs. If the tank is too tight to the structure, it could be caused to flex with the flexing of the boat's structure and fail due to metal fatigue.

Foaming in tanks is a widely used method of installation, as it provides the maximum amount of support for the fuel tank and adds strength to the hull structure.

The down side of foaming in tanks is that it does allow water to accumulate in the base of the foam over the course of a boat's life, leading to corrosion. Note that an aluminum tank won't rust, it will corrode. The problem is that most builders do not provide for any drainage below the tank, so there is no where for accumulated moisture to go.

You may want to consider the strength and design issues, and the builder's original intent. A good alternative may be to foam the new tank in, but provide for drainage underneath the tank. (I did that in my Formula 242 rebuild) http://forums.iboats.com/boat-resto...nger-bulkhead-repairs-w-many-pics-534913.html


The article by Dave Pascoe frowns upon foaming in tanks for the reasons of corrosion and provides an alternate method. However, the article does not adequately address any structural ramifications (weakening) by converting a foamed-in installation to a strapped in (or other) installation (IMHO). So, that is what you need to consider, particularly with a 1,000 lbs of fuel tank.

So, my opinion is to make it substantially the same as the builder originally made it, but perhaps improve upon it by adding some drainage underneath the tank.

Re: Fuel tank replacement ?'s and deck replacement

I agree ^^^. If you foam it in. I'd Coat the Bottom of the tank with 2-3 coats of Gluvit and then Calculate the amount of foam needed to fill the cavity, then tape 3 pieces of hose to the bottom of the tank and then tape plastic over it all and then set the tank in place and shoot the foam in. When you remove the tank the hose would create three drainage channels for water drainage. Kinda like this...