Internal Fuel Tank Install

[rjbathgate]

Hey,

My setup currently uses 2 x 24L plastic tote tanks up against the transom. My RIB also has a 40L internet fuel tank in the bow, however this internal one is fibreglass, which has been "recalled" by the manufacturer... I've read about the potential issues with fibreglass tanks, esp when using 10% ethanol petrol etc...

So...

I want to replace the fibreglass internal tank with something I can use - either stainless steel, or plastic... (unless there is a miracle method to make a fibreglass tank usable?!)

The manufacturer has replacement tanks (well, were getting some in months ago but I still haven't heard anything...!) but I don't really want to deal with them as their service is terrible... so I'm thinking of just going to a boat builder and getting an internal fuel tank that fits.

So I guess I'm just really after some hints/advice on what to look out for when going to a boat builder, so I know what needs to be done and how long it should take them etc etc...

And do I go plastic or s/s for the new tank? Or does it not matter?

And also, I still want the option to use the tote tanks aswell as internal tank (for long trips), so in terms of connections, but I guess I'd just be able to disconnect the main fuel line from outboard so I can plug in a fuel line from tote tank? A selector would be good so i can simply turn a knob and change fuel line from internal to tote, and then still go through same fuel filter...

I've attached a few pics - the first, the tank is under the box step, under anchor locker.
2nd and 3rd just looking down inspection hatch to existing fibreglass tank.

What would the boat builder chop out to get to it? Hull? Floor? Or just anchor locker/step?

Any advice is most appreciated! It's gonna be alot of money so I want to get it right!

Cheers

[PeterM]

I was thinking along the same ' what if?' scenario with my under deck tank. I thought ' surely it cant be that hard' to make a flexible tank ( like the AVON type the RNLI use on the D class boats that is fed into the existing filler hole - then pumped up with air to take up the same shape as the under deck one ? I 'think' this is done in aircraft wings where I am sure you can see the disadvantage of cutting big holes !

Expensive to make in the first place , but cant be more than cutting big holes in the deck ? and when done for one you have a template for more ? ( each bag would have to 'fit' the tank'

Then you set up a tap as you mention to switch between this & any other tanks? Then its a question of tap before or after a filter/seperator etc so as not to have a good tank unavailable due to a 'full' ( of water)seperator.

Surely Henshaw could knock one up ?

[rjbathgate]

Ahh it took me a few reads to understand, but basically you're talking putting a fancy plastic bag into the tank to line it, providing a seal between fuel and fibreglass tank?

Genuis...

Can see it being a bit fiddly and tricky getting it in the tank in the first place especially through the filler hole as it's a relatively long hose/pipe...

But if it does work, that's much better than giant holes in my deck anyday...

Once it's in, and pumped with air, does it then "set" in place? Or simply just like a plastic bag deflate when empty... and then when I fill it back up with fuel ti simply fills the space of the fibreglass tank?

Somehow you'd need to connect the outlet hose of the current fibreglass tank to the plastic bag, but I've got an access hatch to that area...

Anyone got any experience in this?

Where and how would I go about getting something like this? (bear in mind I'm in New Zealand...)

Cheers

[PeterM]

Thats what I'm thinking ! I guess deflate & fill up again as its used. If you can get to the existing pipe it cant be that hard to have feed set into the 'bag' in the same place - so only a small hole needed to connect it.

Just an idea at the mo, but feel sure someone will have already done it somewhere . If I had to do it I'd try this way.

Phone call to AVONS - specialist people , Henshaw and maybe Paul Tilley ( on here ) to chat through if possible / cost etc first ?

Maybe google work to see if you can find an aviation company who could do it near you ?

( oh take the filler hose at the deck - cut if needed & re-connect it later - hopefully that way its easier to get the 'bag/tanl/bladder in )

Pete

[rjbathgate]

Just dropped Paul a PM, cheers

Also read a bit up on this plastic bag option and I'm still interested in doing it the proper way (tank out, new tank in), so any advice on that still appreciated...

I see the bag idea potentially resulting in an unreliable system, if for example a kink in the bottom of bag could prevent fuel from getting the outlet valve etc etc...

Cheers

[paul tilley]

First problem with custom made flexible tanks is having a market big enough to warrent CE approval .second problem with liners is wear due to liner rubbing against old tank surfaces .thirdly it is exceptionally difficult to manufacture a reliable three dimensional flexible tank .Hence we only make two dimensional (pillow tanks ) for racing use ,although some people do use them to give extra capacity on long trips .In this situation i would reccomend either a stainless tank or custom plastic tank from some one like tek tanks. We could make a tank for this situation but it would not be Ce approved and i would not be happy to give any warrenty hence i would steer customers to the solid tank option .

[rjbathgate]

Thanks Paul for our honesty... looks like I've been turned to ripping out and replacing...