Fuel tank replacement

[doug mayer]

Pulled original tank from Osprey 200, 1988.  Found 5 extra holes in the top, just waiting to be poked, and two or three about to go in the bottom. The tank is a 48 gallon rectangle, and I'm thinking of making the new one a 36 gallon rectangle--6" high rather than the 8" original--all else the same.  My reasoning: the boat is not likely to be taken off shore, but mostly used to cruise the bays of Maine.  Fuel is readily available in most harbors and destinations. The 85 lbs. less weight would be good, and more frequent fill-ups would assure fresher fuel.
I'm also considering sloping the tank to keep weight further forward. The tank at the stern would be off the coffin floor by about 2", and ramp down to the coffin floor forward.
I would appreciate group wisdom on installing a smaller capacity tank, and the idea of sloping it. Thanks.

[Capt. Bob]

The general consensus here is that it's better to have and not need than to need and not have. That line of reasoning can be use for many things in life, especially money and fuel.

That stated, I'm in the minority on the fuel thing but in the majority on the money thing. I reduced my 105 gallon tank to 55 gals. because I believe in fuel management systems (in my case Flo Scan) and a sound knowledge of what you do with your boat. Again a minority but I know my needs and monitor them (the flow scan tool) and just don't need all that capacity. Others do so you need to ask yourself just what you're going to use your craft for and stick with it on the water. The other benefits you mention always come into play. A good thing in my opinion but again that's just my opinion.

The money I saved on building a new tank, I put back in other things on my boat. Remember, you can always put 35 gals. in a 105 gal. tank and allow yourself to spend $500 to house air.

Good luck with your choice.

[wingtime]

That depends on how fuel efficient your current engine is.

[mshugg]

I'm also considering sloping the tank to keep weight further forward. The tank at the stern would be off the coffin floor by about 2", and ramp down to the coffin floor forward.

 

On plane this may not be a problem, but off plane running level, you may have remaining fuel at front and pickup at rear. 

[doug mayer]

Thanks for your wisdom. I took the old tank, including the extra holes, to a local machine shop who does a lot of work for Maine commercial fishermen.  He indicated that there would be no price difference between a 6" high tank and the correct 8" high tank.  So far as I can tell, the boat uses about 7 gal./ hour at cruising speed. Most of my destinations using that measure are less than an hour by a lot. But asking the question of you all and reading your comments carefully has been very helpful.  I conclude that we will replicate the original tank, except for the extra holes, and not worry about slope.

Doug

[RickK]

Might as well get the most for the money - you don't want to have to go back under the tank lid again if you don't have to.