leaking inboard fuel tank - options?

[steve-ribnet]

Hi all,
the 90l built-in aluminium fuel tank under the seat/console of my 5.5 tornado has sprung a small leak somewhere - I get a small dribble of petrol running out of the under-seat drain and down the deck, which is making the treadmaster peel up! Probably a cupful over the course of a day.

The section of the tank that I can see from under the seat is of course fine, I can see it dribbling down the inside edge of the console from - i presume - around the side of the tank, but of course there is about 1cm clearance between the tank and seat/console side that I can't see down or access from anywhere else (there is a shelf glassed to the top of the tank at the front under the main console, so I can't see the whole front half of the tank, and not from the inside either as there is a baffle half-way blocking my view of the front of the tank!

The console is glassed to the floor, so I can't just unscrew it.

My question(s):
Are there any products like a leak-sealer that I could add to the tank that anyone has tried?

Alternatively has anyone chopped into the side of their seat fibreglass before and replaced with a hatch ~ 30x20cm ? I'm worrying about the strength of the seat being compromised.

(a bit of a gamble - I could probably isolate the hole being from one side or the other of the tank by blocking the small gaps with temporary sealant)

..and if I do find a hole in the aluminium, how best to repair the tank in-situ? I'm really trying to avoid removing the console!

many thanks in anticipation.

[whisper]

Without seeing pics it's hard to say. It sounds like the seat needs to be cut from the deck, the tank repaired or replaced and then foamed in place and the seat glassed back to the deck...

[steve-ribnet]

hmm, you're probably right. I'm trying to avoid chopping the seat/console out if possible, but would give peace of mind (but no boat over summer).

Photos are here( can't add directly from this work computer)
steve-ribnet - Imgur

here's a pic of the console/seat (photo1). I'm trying to work out the flange arrangement - guess the seat/console has a flange that splays outwards and lies flat with the deck, then a layer of glass sits over this (no screwholes are on the inside)

There are some ominous old screwholes for the wiring loom around tank level in the side of the seat. I suspect a previous bodge-job repair has come undone... The tank sits pretty much flush up against this side (and a 1cm gap on the starboard size between the tank and the seat side at the top)

for good measure, here's under the seat (photo 2) (excuse the mess), and the gap behind the fueltank (photo 3)where fuel puddles up when the jockey wheel is extended. I stuck some plasticine in the corners to rule out a fuel line leak, and fuel is certainly running down from the side of the fueltank. A shelf has been glassed to the top of the fueltank at the front, to hold the battery (pic 4).

There's no foam padding either side of the tank at the moment. When you say 'foamed back in place' can you get fuel-resistant squirty foam stuff? I'm debating squirting this through the screwhole in the side of the seat, but it'll make removing the whole thing harder if necessary later, and probably won't stick to seal it...

thanks

[biffer]

Cut the console out, it's not that hard, you will finish up with a bigger boarder where you will need to cut the tread master back in order to rematch the console back down, just cut round it throw it to one side and take the tank out

[Chris86]

Nasty issue to have!! Id cut it out and replace the tank.. Its the only way it would be right in my head. If welds are starting to fail on the tank you may find youself back to square one a few months after patching up the current one

[paintman]

^^^
Needs to be dealt with properly. Just too much of a risk.

[Wightdiver]

Originally Posted by biffer

Cut the console out, it's not that hard, you will finish up with a bigger boarder where you will need to cut the tread master back in order to rematch the console back down, just cut round it throw it to one side and take the tank out

Just out of interest Biff, how would you go about doing that? I normally cut glass fibre with an angle grinder but under the circumstances would be worried about creating a spark.

[1eyedjim]

i have an aldi special of one of these

Energer ENB518HTL 200W Multi-Cutter 220-240V | Multi Tool | Screwfix.com

did mine in 10 mins and much less mess than an angle grinder. well worth the money

[captnjack]

I agree the only solution here is removing the console and replacing the tank.

Originally Posted by Wightdiver

Just out of interest Biff, how would you go about doing that? I normally cut glass fibre with an angle grinder but under the circumstances would be worried about creating a spark.

You can't really eliminate the risk of a spark, you need to eliminate the fuel (and vapors) instead.

Drain the tank beforehand, leave it open for a few days to let the remaining vapors and any liquids inside evaporate. This also gives the leaked fuel time to evaporate off the deck and from wherever its gone. Check the bilges, take out any drain plugs to ensure they drain of vapors, use blowers if in doubt.

[steve-ribnet]

Originally Posted by biffer

Cut the console out, it's not that hard, you will finish up with a bigger boarder where you will need to cut the tread master back in order to rematch the console back down, just cut round it throw it to one side and take the tank out

not hard for you maybe! A bit daunting but I'll give it a go. Battery tray (glassed to top of tank and insides of console) wiring loom and steering cable will have to come out (eek)

Where would you cut exactly? I presume there is a flange on the bottom of the seat/console moulding as per the attached drawing, and that there is simply a strip/tape of glass matt and gelcoat that overlaps the flange?

Referring to attached crude drawing, would you cut at point A where the edge of the console moulding meets the floor (having cut back the treadmaster as you say), or at point B, where the seat joins the floor at a right angle - effectively cutting through the flange on the bottom of the seat moulding? Or perhaps halfway inbetween?

I was planning on draining the tank and filling full of water, rinsing down the surrounding area and using an air powered die grinder to grind back the fibreglass bonding strip at point A until the console flange is revealed, then dress-grinding the old bonding strip off the console in preparation for new bond.

How would you re-bond? I'm thinking a layer of CSM in resin, then a layer of glass tissue in resin, then flowcoat?

Many thanks

[biffer]

I didn't read it all as I'm putting a floor down. We have air saws here. Cut right in the corner where it hits the floor. Don't bother taking anything off the console. Lift it up with most stuff still attached and put it up the back. Take take out and weld it up. Grind off old flange on deck. Grind round console. Put tank bank in after test. Console back down and glass in. Job done

[nugent]

Originally Posted by steve-ribnet

not hard for you maybe! A bit daunting but I'll give it a go. Battery tray (glassed to top of tank and insides of console) wiring loom and steering cable will have to come out (eek)

Where would you cut exactly? I presume there is a flange on the bottom of the seat/console moulding as per the attached drawing, and that there is simply a strip/tape of glass matt and gelcoat that overlaps the flange?

Referring to attached crude drawing, would you cut at point A where the edge of the console moulding meets the floor (having cut back the treadmaster as you say), or at point B, where the seat joins the floor at a right angle - effectively cutting through the flange on the bottom of the seat moulding? Or perhaps halfway inbetween?

I was planning on draining the tank and filling full of water, rinsing down the surrounding area and using an air powered die grinder to grind back the fibreglass bonding strip at point A until the console flange is revealed, then dress-grinding the old bonding strip off the console in preparation for new bond.

How would you re-bond? I'm thinking a layer of CSM in resin, then a layer of glass tissue in resin, then flowcoat?

Many thanks

Tornado has no flange on there consoles,,

As biff said air saw flat to the floor ,, Or one of these

Tornado tanks are also ali not stainless steel,

[steve-ribnet]

Originally Posted by biffer

I didn't read it all as I'm putting a floor down. We have air saws here. Cut right in the corner where it hits the floor. Don't bother taking anything off the console. Lift it up with most stuff still attached and put it up the back. Take take out and weld it up. Grind off old flange on deck. Grind round console. Put tank bank in after test. Console back down and glass in. Job done

you make it sound simple!
thanks for the tips Biffer I'll give it a go. I have reciprocating 'sabre' type saw

Could anyone suggest how many layers of CSM/glass tissue I should re-bond it back down with?

Wish me luck

[biffer]

1 chopper 1 combo 2choppers should do it

[steve-ribnet]

Originally Posted by nugent

Tornado has no flange on there consoles,,

As biff said air saw flat to the floor ,, Or one of these

thanks - good bit of info
Might wait 'til 23 June for Lidl:
PARKSIDE 10.8V Li-Ion Cordless Multi- Purpose Tool - Monday, 23.06. - Lidl UK

[steve-ribnet]

Originally Posted by biffer

1 chopper 1 combo 2choppers should do it

sorry you'll have to translate for us numpties
is that

1x layer of 300gsm chopped-strand-mat,
then
1 layer of combination 600gsm Woven Roving / 300gsm Chopped Strand Mat
then
2 layers of 300gsm chopped strand mat

(then I presume flowcoat in colour to match?)

thankyou for your patience.

[biffer]

Chopper is chopped strand and combi is chopped strand stitched to a woven Matt Have a look at Matt and you should be looking for a 450 gram chop and something like a 600/300 combi

[paintman]

Originally Posted by steve-ribnet

thanks - good bit of info
Might wait 'til 23 June for Lidl:
PARKSIDE 10.8V Li-Ion Cordless Multi- Purpose Tool - Monday, 23.06. - Lidl UK

I've got the Fein Multimaster - mains powered. Excellent pieces of kit, much more control than a grinder. Not sure how long the batteries will last on a rechageable version

[nugent]

Originally Posted by paintman

I've got the Fein Multimaster - mains powered. Excellent pieces of kit, much more control than a grinder. Not sure how long the batteries will last on a rechageable version

Mine is a fein batt version last well to be honest,,, use it all the time. Cut all this out on one charge. Now sat on tube

[Doug_G]

Replace the aluminium tank with a 'plastic' one.