relocating fuel tank to subfloor

[gatorfan6908]

Are there any issues with relocating the fuel tank to the subfloor? Or is there a good way to fashion a new one? It currently sits directly in the storage area directly underneath the cockpit (center console) where my feet would go.
I am ripping out the present deck to replace the stringers and am looking to relocate the fuel tank to the subfloor to provide more deck space. I have a 1982 Mercury inline v6. I spoke with one person and they instructed me that I would have to add a fuel pump to the system for that particular motor. I dont know if that is true, but I would like some insight.
If I had to refashion a new tank to place into the subfloor, is there a proven way to make it myself, or would I buy one that would fit underneath and fiberglass it in? Any suggesstions or insight would be greatly appreciated. I have been reading this forum for months now and finally decided to make my own account and get in on the discussions with you guys. I know there is a lot of great experienced individuals out there, and I look forward to hearing from you. Thanks for all of your help!

 

[SBTOM]

Re: relocating fuel tank to subfloor

I don't know whether you would need a fuel pump, but it would be helpful to know the size/style of the boat as well as the size of the fuel tank that you want to put in. You could make it yourself but it might not be worth it unless you already have the materials and equipment to do it. I know a guy who made one out of 1/8th inch thick aluminum sheet and it was a process to get all of the correct fittings, coat the inside, pressure check etc.... when you factor in the time/ materials it takes to build the tank, you might be better off just purchasing a plastic or aluminum one off the shelf.

 

[jonesg]

Re: relocating fuel tank to subfloor

What mfger is the boat?
Sub deck tanks require extensive plumbing and regs call for 4 inch vent hoses which exit on the side of the hull to prevent fume buildup.
If it had a tank down there originally its simple, but to change over is quite a little project. The hardware will add up.

 

[gatorfan6908]

Re: relocating fuel tank to subfloor

Length: 17'
Model Name/Description: SEA OX 170
Boat Type: Outboard Boats
Hull Material: Fiberglass
Beam: 6'
Engine: 1982 Mercury v6 90hp
Net Weight: 1100 (without gear, fuel, or motor)

Honestly, after hearing what was said about how pricey it will be, I feel I can just deal with it being under the cockpit. Not that big of a deal anyway. I just would like to go ahead and relocate it since I will have the deck off to replace the stringers. Although, I would most likely purchase a tank, not build my own seeing as how extensive the process would be. Then I would just place it underneath the deck, glass it down, and place vent hoses out the side of the hull, of course I would look at the C.G. Regulations prior to doing any of that. Thanks for your input, if you have anything else, I'd love to hear it!

 

[SBTOM]

Re: relocating fuel tank to subfloor

Well if you are going to buy one off the shelf, there are some options that would make it more affordable. One thing that you could consider would be going with a fully fit out plastic version. I found this link for someone else a couple weeks ago and it still seems like a really good deal. its a 34 gallon tank with all of the fittings for 136$.
http://www.fpmarine.com/Fuel Tanks.htm

If you do go this route, I don't know that I would glass it in. They typically come with an area to attach a bracket. Also, make sure that you plan to put enough foam back in the boat that it will still float if you take on water!

 

[jonesg]

Re: relocating fuel tank to subfloor

Theres lots of tanks on craigslist. I got a 60 gal alum for $100.
Vent hose is reasonable but the external hull vents and the collector box which mounts under the gunnel can be a bear to install unless the cap is off.

Also fill and vent hose has to run under the deck and up the gunnel, its a beach to get that hose and filler cap fitted in right.

 

[guzziprov]

Re: relocating fuel tank to subfloor

If you place it below decks and then just glass it in you will have no way to service it should the need arise. Glass boats have an access port to allow service of the sender as well as a section of floor that can be removed to replace the tank if necessary. Really something to think about.