Tornado 5.5 fitting under deck fuel tank?

[steve-ribnet]

Hi All,
I am replacing the original ~100 litre Aluminium fuel tank in my 1990 Tornado 5.5 because it leaks.

I'd like to replace it with a 'plastic' tank - e.g. Fuel tank, capacity : 91 L - Direct Chandlery

however the closest size that matches would need recessing into the deck some 15cm in order to fit.

Does anyone know if this is possible/advised on a Tornado 5.5? Or should I just get an identical tank fabricated in Aluminium again?

Nugent has some great photos on my original thread
http://www.rib.net/forum/f8/leaking-...tml#post666738 of what I'm trying to achieve.

The old tank is tapered in width towards the top, and sits flush with the deck. Photo: RIBnet Forums - steve-ribnet's Album: Tornado 5.5 fuel tank replacement
so the new tank - if rectangular - would have to sink down by 15cm or so in order to fit under the seat.

If anyone has any advice/suggestions on how to mount the tank if I do cut a hole in the deck - I presume you make a skinned marine ply 'tray' for it to rest on the stringers?

My other option is just to get an identical aluminium tank fabricated. This one is 15 years old.

Old tank dimensions 920mm long x 250mm wide at top x 380mm deep. Old tank tapers to ~360mm wide at the base.

Closest match I have found is Plastimo 91 litre tank, dimensions 910mm long x 300 wide x 410 deep.


Thankyou for any input you can offer

[jeffstevens763@g]

Steve


Try international marine supplies they have a wide range on their site some with keel shaped bottom

Regards jeff

[nugent]

Sit it in deck slightly really is no problem on this hull,
Tornado stuff is normally custom built ali tanks to suit the console,,,,, failing that there is jay wolf who will custom built to your s pec in ali or stainless

[steve-ribnet]

thanks both, I'll check that site out.

Nugent - are those photos from a tornado hull? What size boat please?

I'm tempted to get a replica tank made. Is there a great debate over Aluminium vs stainless tanks? The last tank suffered crevice corrosion after sand and dirt built up in the gap between tank and inside of console, trapping water.


thanks

[nugent]

Originally Posted by steve-ribnet

thanks both, I'll check that site out.

Nugent - are those photos from a tornado hull? What size boat please?

I'm tempted to get a replica tank made. Is there a great debate over Aluminium vs stainless tanks? The last tank suffered crevice corrosion after sand and dirt built up in the gap between tank and inside of console, trapping water.


thanks

5.8 I think it was not got my I pad here will check but there is nothing in the way up front trust ,me

[steve-ribnet]

I think I'm going to wimp out of a plastic tank and get an identical aluminium one built. ("Nooo!" I hear you scream at your computers!)

I was wrong about how long this one lasted. There is a test mark on it from Feb 1990, so I think 25 years is an acceptable lifespan between replacements!

I worry about plastic because 1) I don't trust myself to cut/glass a hole in the floor of the boat, and 2) I worry more about chafing a hole through the plastic tank with cables/crap put under the seat and 3) it's not quite the right size.

There is not much room under the seat and it is used for spare battery/cables/fuel flow gauge/gloves and hats/chocolate bars

The old tank rested straight onto the deck gelcoat (photo album updated), with a flange at fore and aft that was glassed down. Under the tank was a good 5mm of wet sand/sawdust/crud that must have caused the corrosion. photos: RIBnet Forums - steve-ribnet's Album: Tornado 5.5 fuel tank replacement

I am debating sealing all around the perimeter of the new tank with sikaflex or similar, to keep out the crud, but risk trapping water as much as keeping it out...

The other mitigating step I may take is to specify slightly thicker aluminium for the base plate of the new tank, to get another few years out of it

Should I sit the tank on anything other than the deck gelcoat- a sheet of 2mm rubber perhaps? Anything that doesn't hold the water I guess

Old tank just had filler cap (with bleed screw) and one fuel pipe union. New one I will specify with a filler cap, fuel float gauge port, fill and vent lines.

watch this space.

[jeffstevens763@g]

hi steve

use marine flex to seal its cheaper than sikaflex same stuff from marine mastics three tubes about £15.00

[jeffstevens763@g]

Steve

Just a thought I had aluminium bases made for my shock seats I got them powder coated and look well, prevents corrosion if it were me I would sit the tank down on a bed of marine flex have some securing lugs put on the base and screw it down same as they do with seat bases and prevent water and debris getting underneath

Good luck

[steve-ribnet]

thanks for the product links.

I'm tempted to coat the underside of the tank with waxoyl underbody sealant, then seal around the edges with marine sealer as you suggest. If I bed the tank on a bed of sealant it may never come off again!

[steve-ribnet]

ah, not waxoyl apparently, Hammerite recommend against contact with fibreglass.possibly the white spirit in it or something.

[jeffstevens763@g]

Steve

I suppose if there is an air gap beneath the tank then it can be washed out as and when so if the old tank lasted as long as it did that might be the way to go

Cheers