how to remove a below deck fuel tank?

[westicals]

I noticed gas in the bottom of my bilge area and can not find any leaks in hoses, fill house and breather seem fine as well. Im thinking its my fuel tank. anyways, im thinking of setting the depth on my skil saw and starting small until I can expand my hole large enought to remove the tank and land half way on a stringer so I can place new wood and fiber glass later... I have NO CLUE what im doing and if im even on the right path. Any thoughta or ideas?

 

[tpenfield]

Re: how to remove a below deck fuel tank?

Tell us what boat you have and post some pictures . . .

Try to figure out how that fuel tank got in the boat in the first place. Sometimes there will be a way to take it out without cutting, sometime cutting will be needed.

Keep in mind that you are working around exposed fuel and a tank with fuel and or fuel vapors. You do not want to create the big-bang theory all over again.

If the tank is foamed in, then getting to it will be the easy part. Getting the foam and the tank out will be a real chore.

Make sure to empty the tank and plug all the fittings before you start. Then purge the tank with strong detergent & water once it is out.

 

[westicals]

Re: how to remove a below deck fuel tank?

Well I will try to get pics today. It appears to not be foamed in as I see the tank, and wood framing over and around it. And yeah, big bang is only good for keeping me off work, but if I can't move from third degree burns or worse, die... guess I wont be posting or working on her! Lol! I know for sure I put 5 gal in to run her, but its been leaking in my bilge area. What's a good detergent to wash it with? Like engine gunk or?

 

[westicals]

Re: how to remove a below deck fuel tank?



Ok the round hole at the bottom of the picture is where the fill and breather hose go into the tank. Its a 63 gallon aluminum tank and runs all the way back to the motor. You can see the brass fitting in the square notch cut in the floor in front of the engine. It has some foam around it and also wood constructuion over the top of it...

 

[tpenfield]

Re: how to remove a below deck fuel tank?

All we get is one picture . . . that's no fun.

 

[westicals]

Re: how to remove a below deck fuel tank?

Yeah I know. Its all I got right meow. Sorry.

 

[MH Hawker]

Re: how to remove a below deck fuel tank?

About the only way it to cut it out.

 

[Don S]

Re: how to remove a below deck fuel tank?

There is enough information in that one picture to explain how to get it out. You have to cut an opening bigger than the take to lift it out of.

 

[westicals]

Re: how to remove a below deck fuel tank?

Yeah I figured as much. Im just not a boat guy, yet. Lol! I used to work construction tho and have a general Idea of how to do stuff but im so unaware of any special boating fore warnings that might help me avoid extra and unnecessary costs and trouble. I guess this weekend I will be cutting it out and I will take pictures and show as I go. Lol! My next post is going to be about how to set a fuel tank. Lol! Thanks again everyone! I appreciate the help.

My other question was to tpenfield, and im curious if you have any thoughts or suggestions for a good detergent to rinse the tank with?

 

[tpenfield]

Re: how to remove a below deck fuel tank?

I used a grease dissolving detergent . . . whatever was in the house at the time . . . purged it 3 or 4 times and then let it dry upside down so the water (and any remaining fumes) would come out the filler fitting and/or the sender opening.

 

[westicals]

Re: how to remove a below deck fuel tank?

Got the seats out and im getting ready to start figuring out how im going to pull the deck to remove the tank!

 

[toms26t]

Re: how to remove a below deck fuel tank?

If that is vinyl on the deck, remove that to expose the decking. use a stick or tape measurer to measure where your stringers are and mark the size on your deck or peel the entire floor up to expose the wood below it. Most likely plywood that is screwed down or riveted in place. I am fitting the new hoses on my new gas tank in my 22' Islander.

 

[81_chapparel194]

Re: how to remove a below deck fuel tank?

check your sender unit gasket.. this is where mine was leaking, saved me from cutting my tank out. you will notice if it is leaking there. the top of the tank will be damp

 

[westicals]

Re: how to remove a below deck fuel tank?

Yeah I checked the sending unit and the fill hose and breather before making the decision to cut it out. I layed it all out with a chalk line and cut it out and its perfectly on top of the stringer. The plywood was stapled down and a pain to get out. Now I have to remove all the foam! Lol!

 

[81_chapparel194]

Re: how to remove a below deck fuel tank?

Oh ok. You would think that the manufacturer would have put in an access panel for the tank.

 

[oops!]

Re: how to remove a below deck fuel tank?

the tank is located between the stringers and in front of the engine bulkhead.

take a circular saw and set the depth at 1/2 inch..

cut a small hole at all of the 4 corners of the tank to find the stringer, front bulkheads, and rear bulkheads....

once you have established where the stringers are.... cut the floor (deck) down the middle of the stringer. repeat on the opposite side.

next, cut in the middle of the bulkheads. and remove the deck to expose the tank.

by cutting in the center of the stringer, you will have a "flange" to attach your new deck to....

the tip of an electric chain saw will make quick work of the foam around the tank.

usually, the tank it self has two flanges on either end with 3 screws. remove the screws,,, and start pulling the tank up....

the tank will be "stuck" to the hull via left over foam... but with the majority of the foam cut.... it will come up.

you can seal the current tank with a gas tank sealant... or have the tank re welded (tough to do)... or replace the tank.

to re install the deck after the tank replacement, follow the instructions in the sticky called "how to foam a hull and glass a deck, in the restoration forum "how to's"

all fiberglass, resin, gas tanks... can be purchased right here thru iboats.com

 

[81_chapparel194]

Re: how to remove a below deck fuel tank?

Yeah I checked the sending unit and the fill hose and breather before making the decision to cut it out. I layed it all out with a chalk line and cut it out and its perfectly on top of the stringer. The plywood was stapled down and a pain to get out. Now I have to remove all the foam! Lol!

Please post pics of the process from start to finish.

 

[SteveMcD]

Re: how to remove a below deck fuel tank?

Anybody that would tackle this head first is a boat guy. Been there, done that. Reinell designed my boat to funnel water into the fuel tank compartment, where it was inaccessible for inspection. No sealant whatsoever used on the deck, and if the water couldn't seep in, they cut a hole for it to run in. Then they covered it all with that grass looking carpet. You may have a breach in your bilge bulkhead too. Don't forget about that while the tank is out. I made the mistake of trying to replace the whole bulkhead instead of just the bottom 6" that it needed. A lot of unnecessary work and time. On the other hand, that's how I found out my engine stringers were full of rotted mulch. It is ugly what water given two or three decades can do. I am isolating my wooden components with a fiberglass barrier so if one does get compromised, it wont conduct water to any others. If you do have a new tank fabbed, make sure it meets Coast Guard specs. It must not be able to accumulate water on top, the compartment must be lined with neoprene or other material to prevent abrasion, etc. They are on the CG website. My 65 gallon tank ran me $650. When I replace the deck, I think I will use some form of sealant, and omit the drain hole, and the 6" lip.