Fuel tank on 23 cc

laser · #1 09-20-2003, 12:18 AM

My 70 gal tank is seeping - water test not fuel - so I've got to get a new one. Wanted to move up to 100 gals but don't know if there is enough room. I have removed the aft well in my project 23 and the I/Os are also gone.
Has anyone done a V bottom tank and cut the platform out?

Bill

I'm practicing 1/2 of the 4 boat theory

FELLOW-SHIP · #2 09-22-2003, 09:54 AM

On my 23 CC I replaced my 100 gallon with a 120 gallon tank. Same H 12” and W 28” just longer 7’ if I remember correctly. It starts just in front of the CC just behind that deck hatch there and it runs to the 90 Degree turn in the stringers just about 3’ before the transom. The problem with a V bottom tank is the SeaCraft is a variable dead rise hull you might find that the front of the tank would have to be a different angle then the back of the tank to rest properly in the hull another problem could be that the tank could rest with a forward tilt again because of the variable dead rise thus you could have gas in the tank but at idle speed you might get air in the gas line and have the motor stop running even though you have 15 gallons of gas still in the tank.
FellowShip [img]images/icons/cool.gif[/img]

FELLOW-SHIP · #3 09-22-2003, 02:01 PM

Now this is coming from my memory and I am not as young as I use to be but the old 100 gallon tank was 12”H x 28” W x 69” long = 23,184 Divided by 232 = 99.93 gallons. The new tank is 12”h x 28” W x 84” long = 28,224 Divided by 232 = 121.66 gallons. Which is perfect length to fit in that space talked about above. I put a new deck in for the gas tank and also installed two bulk heads in one in the front and one in the back of the tank.
FellowShip [img]images/icons/rolleyes.gif[/img]

FELLOW-SHIP · #4 09-22-2003, 02:04 PM

This is the method I installed the tank.
http://www.yachtsurvey.com/fueltank.htm
FellowShip [img]images/icons/grin.gif[/img]

FELLOW-SHIP · #5 09-22-2003, 02:09 PM

Should have said this is the method I used to install the tank. I also had the manufacturer of the tank weld two 90 degree brackets in the front and back of the tank that I screwed into the gas tank deck.
FellowShip [img]images/icons/cool.gif[/img]

Daniel · #6 09-22-2003, 05:38 PM

Thanks. Where might a guy go to get a pressure test done on a tank? Is it best to do it with the tank removed?

laser · #7 09-22-2003, 06:03 PM

I ran into that same question with mine. I had taken it out of the boat already to get it checked out. A boat yard buddy said to just fill it with water and check it for leaks - mine leaked!! It turns out that I already had 100 gals. so now the new stainless tank is going to be 1 foot longer for about 20 gals. more.
If you do the water test then you must make sure you can get all the water out [img]images/icons/smile.gif[/img] We've used fuel tank companies (they make and repair tanker truck tanks) to pressure test tanks but they have to make fittings and be careful not to blow out your sender. You might also check with a radiator company.

Bill

I'm promoting the "Yes, Honey it will look as good as the other boat " theory

Capt Chuck · #8 09-22-2003, 08:00 PM

Hi Disaster & Generaider
I replaced my 100 gal factory tank in my 1978 23' superfish CC in 1995. I also replaced the floor it sat on. I had a new tank (still square) made here in Fl that was CG approved and Tig Welded. it was 135 GAl. I still had room for a 15 gal fresh water tank from the front of the tank to the rear of the forward deck hold in front of the console. I ran the fill for the fresh water up through the console seat (inside corner& out the side). I can get to the tank through a hatch I installed in the back wall of the forward deck hold. The extra weight makes a big diference. The fuel tank also had "L" brackets welded at the top which screwed into the box stringers. The tank was coated with zinc cromate and cold tar epoxy and foamed in. Any measurements or further questions I can get you if wanted.I think the tank was $600. And I had Mike @ Wildfire Marine here in Stuart do the floor and installation.
Good luck?
Capt Chuck (shellback)

If she asks "how much did it cost?" LIE!

Daniel · #9 09-23-2003, 01:46 AM

Fellowship-- How much longer is the new tank than the old one? I want to put in a larger tank as well, but don't want to have the air problem.

laser · #10 09-23-2003, 12:26 PM

HI Capt. Chuck,
Thanks for the info. I'm going to be mounting twin OB on a float bracket (pulled the twin I/Os) and was thinking of putting a fresh water tank in the bow storage box. I have a nice storage area in front of my console where I think you put your water tank. When you said the weight makes a difference I assume the water tank helps the boat ride smoother? Can you send pics of your install?
Bill