Surgery required - The Nashers revenge

[Bigtalljv]

I think that discussion might want to wait until you see the method of failure of your existing tank. then you can figure out the best tank for your situation. they all have weaknesses. the bladders are cool but are at least 4X the price. $2500 US for the custom 60 gallon one I looked into.

[lakelandterrier]

I'm sure it is repairable, but a bit complex... I know I'd have problems if my tank failed with the jockey pods moulded into the deck.

Should be a cracking thread to keep us informed of progress.

[C-NUMB]

Hope it will be an easy fix!


Have been using this type of tanks lately,

Ribworld

Never had any issues, but not sure if would use one in a fixed under deck application.

Ali seams to be pretty forgiving, recently was shown a 130 L ali tank that was filled with water and totally frozen last winter, it was swollen and partly out of shape, but still no leaks or cracks!

[Cookee]

Originally Posted by Chris

Don't forget GRP...

Hundreds of Osprey's swear by it

I would be interested in hearing what resins they're using for petrol - we have used GRP for diesel with great success but with the new additives GRP petrol tanks are not recommended by our suppliers.

[Hightower]

Originally Posted by Chris

Don't forget GRP...

Hundreds of Osprey's swear by it

And don't forget to install good filters to catch all the resin debris that will get sucked up during use

Sorry you'll have to do major surgery at some point Nasher, can you not install another tank in a more convenient position.

[mister p]

Originally Posted by mister p

Buffer, the mesh you mention is invariably in foam blocks now. But I agree about contamination. Water being the main issue here as we're on about o/b's in this case.
The access to RIB tanks for removal of foam blocks through filler is easier than fast fill race tanks I believe, should tank need cleansing.

Obviously, Biffer, my apologies for the typo.

[biffer]

Originally Posted by mister p

Obviously, Biffer, my apologies for the typo.

Been called a lot worse

[Nasher]

Had a good look over the boat and fuel tank yesterday.

Sorry, didn’t think to take any pictures, which would negate much of the description below.

So the good news is that there is no split in the tank itself.

The Stainless Steel tank sits in a void under the glassed in deck, there is a 4 inch inspection hatch between the jockeys to access the fuel gauge sender, and the three tank pipes come up through the deck into the Port side Jockey - Filler Neck, Vent, and Outlet pipe.
These are roughly 2/3 of the way back along the tanks length and slightly off to the Port side. Filler Neck is obviously a much larger pipe than the Vent, and the Outlet is smaller still.
I’m not sure how the tank is ‘fixed’ in place in the void, but can ascertain that it is smaller than the void by @ 1 inch all around.
The void has a drain hole into the well in front of the Transom.

The method of bringing the three pipes up through the deck into the Jockey is what’s caused the problem.

A hole has been cut in the deck inside the jockey seat @ 6 x 8 inches which the three pipes protrude up through in a line.
Two pieces of ply have been cut into rectangular spacers with the 6 x 8 hole in the middle, and bonded/flowcoated over the hole, forming a small tower around the pipes – God knows why.

A piece of 2mm thick stainless Steel sheet has had three holes drilled in it to fit over the pipes, then it’s been screwed down over the hole and mastic or similar used to seal the gap between pipes and stainless sheet. The hull is a 1996 Hull, and I’m assuming it was built like this as I’ve had the boat 10years and it’s one of the few things I’ve not ripped out and rebuilt.
The holes in the stainless sheet around the Vent and Outlet have a lot of clearance around them, but the hole around the Filler Neck has only a few mm clearance all around.

Whatever holds the tank in place has obviously compressed or broken over the years, because I can now move the tank @1/2 inch in all directions.

Over the years the tank has moved around and the stainless sheet has worn away at the Filler neck. The rough seas off Dartmouth were probably the last straw and the Filler Neck has sheared off at the worn point. The Vent and Outlet were protected by having more clearance around them.

None of this could be seen from above until I ripped out the stainless sheet and two ‘spacers’ yesterday.

I’m assuming the Filler neck sheared off before I poured 60l of fuel in from jerry cans the other day, with the two bits of Filler neck misaligned, some would have missed the tank and gone straight into the void around the tank and then out into the bilge.
Also, with the Filler Neck being 2/3 of the way towards the stern, every time the bow of the boat went up a small amount of fuel would come up the filler neck and liberate itself.

I blocked off the Vent and Outlet Pipe, then Cut a length of old Bicycle inner tube with the valve in the middle.
I put a tight knot in one end, then stretched the other end over the remainder of the Filler Neck and put a Jubilee clip round it.
By doing this I was able to add 3psi of air pressure to the tank, which made the inner tube bulge, and see if it held air.
It took @15mins to go down to zero with a lot of hissing at the Fuel Gauge sender which I’ll sort out soon.

So, I am happy the tank doesn’t have a hole in it.

The good news is of course that because of the tower had been built around the pipes the break is a couple of inches above deck level, so with a longer bit of flexible pipe I can still connect to it.

Not completely sure about re-fixing the tank yet, but believe it can be done with expanding foam meaning I’ll just need to drill some small holes to inject it through, which can be inside the jockeys.

I’m going to tidy up the hole in the deck inside the jockey with some flowcoat and leave it as is.
I use the Passenger Jockey as a wet locker anyway, so it will act as a drain down into the bilge.

Anyone have @500mm of fuel hose with an ID of @38mm?

Nasher.

[bedajim]

Originally Posted by Nasher

Had a good look over the boat and fuel tank yesterday.

Sorry, didn’t think to take any pictures, which would negate much of the description below.

So the good news is that there is no split in the tank itself.

The Stainless Steel tank sits in a void under the glassed in deck, there is a 4 inch inspection hatch between the jockeys to access the fuel gauge sender, and the three tank pipes come up through the deck into the Port side Jockey - Filler Neck, Vent, and Outlet pipe.
These are roughly 2/3 of the way back along the tanks length and slightly off to the Port side. Filler Neck is obviously a much larger pipe than the Vent, and the Outlet is smaller still.
I’m not sure how the tank is ‘fixed’ in place in the void, but can ascertain that it is smaller than the void by @ 1 inch all around.
The void has a drain hole into the well in front of the Transom.

The method of bringing the three pipes up through the deck into the Jockey is what’s caused the problem.

A hole has been cut in the deck inside the jockey seat @ 6 x 8 inches which the three pipes protrude up through in a line.
Two pieces of ply have been cut into rectangular spacers with the 6 x 8 hole in the middle, and bonded/flowcoated over the hole, forming a small tower around the pipes – God knows why.

A piece of 2mm thick stainless Steel sheet has had three holes drilled in it to fit over the pipes, then it’s been screwed down over the hole and mastic or similar used to seal the gap between pipes and stainless sheet. The hull is a 1996 Hull, and I’m assuming it was built like this as I’ve had the boat 10years and it’s one of the few things I’ve not ripped out and rebuilt.
The holes in the stainless sheet around the Vent and Outlet have a lot of clearance around them, but the hole around the Filler Neck has only a few mm clearance all around.

Whatever holds the tank in place has obviously compressed or broken over the years, because I can now move the tank @1/2 inch in all directions.

Over the years the tank has moved around and the stainless sheet has worn away at the Filler neck. The rough seas off Dartmouth were probably the last straw and the Filler Neck has sheared off at the worn point. The Vent and Outlet were protected by having more clearance around them.

None of this could be seen from above until I ripped out the stainless sheet and two ‘spacers’ yesterday.

I’m assuming the Filler neck sheared off before I poured 60l of fuel in from jerry cans the other day, with the two bits of Filler neck misaligned, some would have missed the tank and gone straight into the void around the tank and then out into the bilge.
Also, with the Filler Neck being 2/3 of the way towards the stern, every time the bow of the boat went up a small amount of fuel would come up the filler neck and liberate itself.

I blocked off the Vent and Outlet Pipe, then Cut a length of old Bicycle inner tube with the valve in the middle.
I put a tight knot in one end, then stretched the other end over the remainder of the Filler Neck and put a Jubilee clip round it.
By doing this I was able to add 3psi of air pressure to the tank, which made the inner tube bulge, and see if it held air.
It took @15mins to go down to zero with a lot of hissing at the Fuel Gauge sender which I’ll sort out soon.

So, I am happy the tank doesn’t have a hole in it.

The good news is of course that because of the tower had been built around the pipes the break is a couple of inches above deck level, so with a longer bit of flexible pipe I can still connect to it.

Not completely sure about re-fixing the tank yet, but believe it can be done with expanding foam meaning I’ll just need to drill some small holes to inject it through, which can be inside the jockeys.

I’m going to tidy up the hole in the deck inside the jockey with some flowcoat and leave it as is.
I use the Passenger Jockey as a wet locker anyway, so it will act as a drain down into the bilge.

Anyone have @500mm of fuel hose with an ID of @38mm?

Nasher.

I'm sure I've got some pm your address where it can be signed for

[Nos4r2]

Think I've got some here too.


Not sure about using expanding foam-I reckon you'd need to use very very little or risk damaging the deck.

[lakelandterrier]

Good news that you don't have to cut the deck up to extract & repair/ renew the main tank

Just a thought & I expect you're way ahead of me - but is it worth checking an top of the filler piper problem, that there has been no damage to the tank itself from its moving around? It would be a right PITA to repair the filler pipe, the find there's still a leak somewhere.

[Ian M]

Well, at least there is some good (ish) news!
I hope the repair is as painless as it now appears to be.
Good luck

[butty]

Nasher, i have cut the deck of an Ocean RIB to replace the S/steel fuel tank with a plastic one a few years back.

I can answer some of your questions regarding how the tank was held down in that boat, it was in a void between the 2 longitudinals and then held front and aft by plywood bonded between. the gap around the edge was fill with expanding foam.

this boat i owed at the time had a similar issue to yours, due to the foam being the only form of stability for the tank, the tank moved over the years as the foam degraded, from fuel spillage and water ingress.

self expanding foam absorbs water better than a sponge, and fuel makes it compress a little more easily it would appear.....

so i removed the tank and then set about removing all the foam which was quite heavy due to all the liquid it was retaining!!!!

just thought i would share with you my experience of this.... good luck and if you want any more info pm me...

[Nasher]

Thanks guys

Bedajim – PM on the way.

Butty – Nice to know I’m not the only one.
I’ve not seen Malcolm or Colin recently, the guys from Windsor Brothers who made Ocean RIBs, but will mention it when I see them.
I’ll also send a quick PM up to Razorbill in case he’s not seen this so he can check the filler neck on his 6.5.

I really don’t want to cut the deck out etc just to dig out the old foam, so will leave it in place and add some more at strategic points.
Obviously the only bit I’ll struggle with is getting it underneath, so will have to assume what’s there is OK but just a bit compressed.
I’ll look out for a closed cell version which won’t hold the water.

So, to the RIB builders on here, assuming unlike me you’re doing it with a new boat that doesn’t have the deck in yet, what’s the best method/stuff to secure an under-deck, built in tank?

Nasher