Fuel tank removal

awthacker

awthacker

Junior Member
Since the engine is down anyway, I decided to pull the gas tank for inspection and/or replacement. Removing the foam around the tank was the least enjoyable project I've gotten into, so far. I used a pressure washer, hammer, and flatbar to remove the foam. If the pressure washer is the easiest way, then I'll say "there ain't no easy way". It was a little laborsome lifting the cherry-picker in and out of the boat, but the lifting of the tank was quick and easy with this set-up. I posted the dimensions of my 82 cuddy's original tank on the other thread. It's 60"L x 26"W x 11H, 60 gallons.

The stringers look pretty good, so I don't think I'll cut the floors out for any reason. I need to put a new PVC pipe in place. Should the bulkhead be sealed around the PVC? It's definitely not... rotten water looks to have been sloshing around down in there for awhile. The bulkheads are a bit rotted at the bottom. Is this okay? Can I just dry them and patch them up, and should they be sealed, so that the PVC pipe is the only way water flows from front to back?
 

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I would think that the only reason you'd even need the pvc is if you were gonna refoam.... My V doesn't have pvc but the resto was done by the P/O
 
Whether or not to foam was my next question. Seems like moisture trapped in the foam is what did the tank in. Bad design? I was thinking of just enough foam to hold the tank firmly in place. Is there an alternative way to secure the tank? Is it okay for saltwater to wash around beneath the tank?
 
I think the fuel compartment has to be sealed. the pvc is to allow water from the front to travel to the rear and be pumped out the bilge pump. if the fuel tank were to leak, the gas would flow to the bilge and go boom when the pump kicked on.
 
Fuel tank compartment doesn't have to be sealed... MANY boats have the fuel tank in the engine compartment and the bilge pump, float switch, and anything else in there should be ign. protected.

The foam is used to physically mount the tank.. you can tab it in with glass, or strap it down, or box it in with wood instead.

Foam is MUCH faster and easier in a production environment where the rest of the hull is getting foam in various places anyhow.
 
just my 2 cents...

I replaced the original tank on my 84. The original setup was foamed in. PVC passing water from bow to bilge, bypassing the tank compartment and tank hatch sealed with silicone. This setup lasted 25 years. So I stopped pondering what to do and just replaced exactly the same way.

If you are foaming in then definitely make sure no water can enter the tank compartment from bilge or hatch.

And I agree that the power washer method was "best" and that wasn't very easy either. Be careful to find all the little pieces of foam that are now everywhere in your bilge.
 
I think foaming a tank into the bottom of a hull, then believing water won't get in there has lead to a lot of premature tank failure...sooner or later I'll have to replace one and I'll be figuring out how to ensure moisture won't be held against the outside of the tank, including the bottom it rests on and how best to drain it out of the compartment...

Keep in mind the bilge is not the only area electrical connections are found...sending unit on top of tank(enclosed compartment) is continuous electrical feed while running...on/off w/ign switch...
 
I haven't had to replace a tank yet, and truthfully, I hope I never have to... BUT...if I did have to replace a tank the first thing I would do is coat the tank with a sealer. Polyurethane, epoxy, vinyl, rubber, paint... something. The trick is to make a permanant barrier between the metal and the water. Hell, I might even consider having it Rhinolined like a truck bed. Once it's sealed your only consideration would be mounting it so it doesn't move.. and I would think that some foam or a few strips of glass could take care of that. :head:
 
Here's what they look like after pressing against wet foam for 30 yrs.

Coating it is a good idea. Then some maybe glassed wood "feet" to hold it off the bottom, and minimal foam around the sides/over the top edge, to hold it firmly in place is what I'm thinking.

I'm debating two options for drainage. Either nix the pvc and allow a gap under the bulkheads for water to flow to the back. Or glass one or two PVC pipes in and seal the fuel compartment completely.
 

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I didn't foam on mine. I set the tank on pressure treated 2 by 4's which I 5200ed to the bilge and then covered with thick beads of 5200 before setting the tank on top. Be sure to let the 5200 cure before adding fuel to the new tank. This lets any water easily drain away from the tank and let the compartment dry out.

And Reel, something about the fuel sender always scared me so its disconnected. LOL.
 
bradford said:
I didn't foam on mine. I set the tank on pressure treated 2 by 4's which I 5200ed to the bilge and then covered with thick beads of 5200 before setting the tank on top. Be sure to let the 5200 cure before adding fuel to the new tank.
Click to expand...

hope you never have to get THAT one out.... your only hope would be trained termites to chew the wood out LOL
 
awthacker said:
You mean the pieces that like to get stuck under the float switch and keep the bulge running?
Click to expand...

they'll also get stuck in the pvc tube and in the drainage holes in the stringers. You'll be amazed what you can find if you start reaching your hand into dark places....every screw, nut, washer, sinker, hook, mussel, and crab claw that ever hit the deck and bounced left....
 
Might want to check with GarageNC but Coal Tar Epoxy works wonders on the fuel tank. It is made for submersion in salt water (ie. metal work boats, pipelines, etc.). I spent a few hours and dollars painting my new aluminum tank with zinc chromate and then overcoated with satin black rattle cans. My boat guru buddy showed me how a little acetone on a rag would easily remove the paint and we went with the Coal Tar instead. I have never seen anything tougher in a two part paint.

My 1983 center console did not have the fuel tank compartment sealed. In fact it looked as if they had cut the rear bulkhead down to nearly even with the top of the tank. There were four plywood wedges under the tank for support, two scrap pieces of wood screwed to the top of the stringers perpendicular to the keel to help hold the tank in place and then foamed. My original tank was beige in color.
 
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