Fuel tank options?

[Autolux]

I now have all the timber and fiberglass for my rebuild and upgradign of an ex RNLI Atlantic 21 I have.
I am powering it with a yamaha 200hp hpdi.

Regarding a fuel tank, do I get a custom one made that will fit under the deck (will be very narrow and long and most likely costly or could I fit a tank in each of the new double jockey seats I have for it and connect together?

I could also just buy one and sit at the rear of the jockey seats agains the transom..

[mhb100]

Originally Posted by Autolux

I now have all the timber and fiberglass for my rebuild and upgradign of an ex RNLI Atlantic 21 I have.
I am powering it with a yamaha 200hp hpdi.

Regarding a fuel tank, do I get a custom one made that will fit under the deck (will be very narrow and long and most likely costly or could I fit a tank in each of the new double jockey seats I have for it and connect together?

I could also just buy one and sit at the rear of the jockey seats agains the transom..

What capacity can you get from each seat pod, and what range do you want? You may even need to do both as most boats of that size and engine spec would typically have c200L. Gut feel you will regret if you don't

[mhb100]

I meant to say you will regret if you don't do one under deck. Perhaps cost it up?

[willk]

IIRC the 21s had a pair of underdeck tanks that gave those wee engines a three hour flat sticks duration - possibly not such a large capacity?

An single underdeck tank will be long and narrow - that's normal. It does spread the weight around and keeps the COG low. Tanks in the consoles/seats raise the COG and you'll be surprised by how little they hold. A tank at the transom is gonna end in tears, IMO. IIWY, I'd work out what sort of range I wanted and do the math on an underdeck. You'll find WOT fuel burn for that engine fairly easily.

[Autolux]

Ok underfloor tank it Is! I can get their made from aluminium or stainless. Are there other options or is one recommended more than the other?

[ShinyShoe]

MDPE? Several suppliers - certainly cheaper than metal... don't know about longevity

It seems the most common reason to take a deck off - is a leaky tank (any material)...

...I'd want to set it up to be accessible to remove as required

[Autolux]

Just looking at Moeller tanks from the US.

[Chanchan168]

Either tektanks or shop4tanks will give you options in plastic, stainless or Ally and can also custom make any shape.

I had to remove my deck as I had a leaky tank. It’s a hell of a job, messy and a lot of work. I personally won’t be putting an under deck tank back in as I wouldn’t want to do the job again. I’ve gone from a 350l under deck to a 150 plastic tank in the console.

I’ve been told that shifting the weight higher up from underdeck to console will not make hardly any difference due to the smaller tank size.

Good luck

[GuyC]

In my Pac 22 the stainless tank had given leak free service since 1991. I have changed it for a bigger custom made plastic tank from Tek Tanks. It was expensive but it is a thing of beauty.

It would certainly be worthwhile getting a quote as that may drive your thinking.

[Autolux]

Originally Posted by GuyC

In my Pac 22 the stainless tank had given leak free service since 1991. I have changed it for a bigger custom made plastic tank from Tek Tanks. It was expensive but it is a thing of beauty.

It would certainly be worthwhile getting a quote as that may drive your thinking.

How much was the custom.made tank and what size?

[nugent]

200 ltr. Trek tank fits further up front I the hull I did one few years back with. 200 mercy on back end

[nugent]

Can not find photo any place originally built a stainless one to fit here but then found a plastic tank same size who went for safer option, (did not trust my welding)

It fits nice here and balances boat out fine

[GuyC]

Originally Posted by Autolux

How much was the custom.made tank and what size?

The tank was £1000 and was broken down into about 50% for the HDPE tank itself and 50% for the fittings. I've attached the drawing of my tank for info. In addition to the usual fittings it has a supply and return for a fuel polishing system plus that price included the fuel gauge.

I measured the space the tank goes into a lot of times and then I built a mock up using 1"x 1" softwood to make sure it fitted and to fabricate the bearers in the right position. Tek Tanks require a solid floor so I have an 18mm ply floor that rests on the bearers.

The original tank was 90 litres and this one is 148 litres which is sufficient to get across the English Channel or to St Kilda and back from North Uist which were my targets

[nugent]

Jay Wolfe will copy or Manu to any size also in Ali or stingless

https://www.shop4tanks.co.uk/

[Autolux]

Ok I have just just quotes for both 316 stainless and 5083 marine alloy.

Its a V shaped tank being installed between the stringers under the deck of an Atlantic 21.

What are the pros cons of the stainless vs alloy or what should I go for?
(for the sake of this, presume both same size and cost)

[Chanchan168]

I personally would choose poly over both, but that’s just me.

There are issue with condensation with metal tanks and welding problems, but if possible I’d choose 316 over Ally.

[Autolux]

Ok thabks. There is another option and that's MDPE plastic, like HDPE but it's medium density. Thanks for diesel tanks and tektanks say they cannot sell it as for petrol although people do use for petrol.

[Chanchan168]

Did you speak to Jaywolf from shop4tanks??

[Autolux]

Originally Posted by Chanchan168

Did you speak to Jaywolf from shop4tanks??

That's where I was given the option of stainless or alloy but not poly?

[Chanchan168]

Ah ok.makes sense