Custom Gas Tank fabrication & Installation

[nightfisher]

I am customizing a 20' aluminum boat hull from the frame up and want to make the weight distribution uniform in the boat. Will most likely go with an inboard with jet drive power plant.

It is impossible to locate a tank in the floor because of the many stringers.

I am toying with the idea of mounting long thin tanks on both sides connected by hoses to a small reservoir in the middle of the boat.

I am wondering if anyone knows of a boat builder that has side tanks and how they are installed/ formulated?

Do you think gas would flow enough from one side to the other on fill-up if I used 3" x 6" aluminum piping on the sides, with a small 3 gallon reservior in the middle?

Any ideas or suggestions, with possible pics, would be grreatly appreciated.

 

[dingbat]

Re: Custom Gas Tank fabrication & Installation

Interesting concept. I would worry about sloshing.

FWIW: Using 3" x 6" tubing will require roughly 12.5 " of length per gallon.

 

[Mark42]

Re: Custom Gas Tank fabrication & Installation

A reservoir is not needed in the middle. Each saddle tank (side tank) needs its own fill and vent. Then run fuel feed line from each tank to a common 3 way valve then a line to filter then to motor. Make sure the custom tanks have top side fill/vent/feed fittings only to meet CG requirements.

There are a number of poly saddle tanks available, probably for less than you will spend on custom made aluminum tanks, and they will never corrode.

 

[SteuryLover]

Re: Custom Gas Tank fabrication & Installation

My Steury center console has saddle tanks in each side. Here is a shot, they drain equally into a water/fuel filter. They are 19 gal per side. It allowed the boat maker to drop the floor farther down to create free board. There may be other advantages but not sure. They are very easy to access to service that is for sure.

 

[arks]

Re: Custom Gas Tank fabrication & Installation

A reservoir is not needed in the middle. Each saddle tank (side tank) needs its own fill and vent. Then run fuel feed line from each tank to a common 3 way valve then a line to filter then to motor. Make sure the custom tanks have top side fill/vent/feed fittings only to meet CG requirements.

That's similar to how my boat's setup but I've got twins, so the fuel lines have additional valves (for cross-feeding) and each tank has its own filter.

I'm a big fan of aluminium tanks. They won't corrode if installed properly (my boat's 25 this year). Plastic tanks can permeate and smell up the boat with fumes, not to mention the possibility of a static spark or seam splitting.

SP sheet metal has been in business for a long time and will fabricate whatever you want.
Google 'sptanks dot com'.