Thinking about a custom belly fuel tank

[chille51]

There's cheaper ways to accomplish what you want. Consider the formula which is weight x distance. you could use 100 kilos of fuel and move it 1 meter (the effect or moment having a value of 100)
Now think about moving 2 batteries at 75 kilos but move them 4 meters (up to the bow maybe) the moment (75x4) would have a value of 300. effectively having 3 times the value in a shift of a lesser weight but a further distance. Adding weight may not be the best solution, but consider shifting existing weight to accomplish what you need. If you are bent on adding weight, try throwing the equivalent (lead?)of the tank you suggests weight (full of fuel) in the locker and see how she rides

Thanks. I did consider moving batteries into the cuddy but I plan to sleep in there at some point, plus the only place to put them would be where I already carry my downrigger balls and anchor chain etc. There is also a freshwater tank up front that I keep filled. I'm not really hoping to add weight, but like you said move existing weight. Fuel weight in this case. I'm not planning to have the belly tank as an additional fuel tank, but rather instead of the one currently in the stern. Regardless though, you make some good points to consider.

 

[chille51]

I take it your tank currently is in the back of the boat. Can you not get a belly tank with fill, breather lines and suction to engine in the rear so you do not need to have a modified one made? You may need a deck plate for fuel sender

I'm not sure I totally follow what you're suggesting? Yes, factory tank is in the stern, below the motor well. Are you suggesting getting a Moeller tank that extends from the fish box into the space below the motor well, with connections there? If so the motor well and fish box are not directly connected, I'd have to cut out a chunk of the deck and probably some stringers - so structural work I'm not hoping to get into.

This thread is probably the best walk through of the guys that have used the Moeller tanks. They both had to modify the tanks by cutting off the fill tubes and relocating them, which I figure must make any certification void?

https://www.arimaowners.com/index.php?topic=16739.0

 

[salmonkiller01]

I'm not sure I totally follow what you're suggesting? Yes, factory tank is in the stern, below the motor well. Are you suggesting getting a Moeller tank that extends from the fish box into the space below the motor well, with connections there? If so the motor well and fish box are not directly connected, I'd have to cut out a chunk of the deck and probably some stringers - so structural work I'm not hoping to get into.

This thread is probably the best walk through of the guys that have used the Moeller tanks. They both had to modify the tanks by cutting off the fill tubes and relocating them, which I figure must make any certification void?

https://www.arimaowners.com/index.php?topic=16739.0

Way too much work if you have cut out strings, decks and bulkheads.

 

[Aces]

I would just get a fuel bladder that you can roll up and out if the way when it’s empty

 

[BC Coast Pilot]

Thanks. I did consider moving batteries into the cuddy but I plan to sleep in there at some point, plus the only place to put them would be where I already carry my downrigger balls and anchor chain etc. There is also a freshwater tank up front that I keep filled. I'm not really hoping to add weight, but like you said move existing weight. Fuel weight in this case. I'm not planning to have the belly tank as an additional fuel tank, but rather instead of the one currently in the stern. Regardless though, you make some good points to consider.

Use Sealed batteries

 

[chille51]

I would just get a fuel bladder that you can roll up and out if the way when it’s empty

Thanks, I admit that I forgot about that option. It did come up on the Arima forums now that you mention it, but I can't recall if anyone actually did it. I will take another look.