Stainless steel diesel fuel tanks?

[tillergirl]

Wansworth's #37 made me to think back to a little worry; weight aft. Leo has poured over the original plans over the years so I assume and hope that he has reflected on the weight distribution. With the engine and extra electrical 'engine' plus the substantial battery store is already 'quite heavy'. Then seeing the location of the diesel tanks immediately struck me as high and a huge amount of weight aft. Of course there is little bilge room in Tally Ho so the tanks cannot be there: and he has to locate water tank(s).

I don't remember Leo talking about the weight distribution mcuh but perhaps I missed it. I hope he has done some calculations.

PS: Kukri, your post happened the same time as me. Looking at the plans don't really make me feel happier. I hope I am quite wrong.

 

[Wansworth]

Probably TallyHo waseffectively a coastal cruiser which out pretensions to long distance voyage ing and with a very small auxiliary.

 

[garymalmgren]

I was struck by how large the tanks were and how high they were positioned.

 

[Rich the Scribbler]

I'm hoping someone can help with an issue I've got with the stainless steel tank on my 30-year-old kit-built Santa Barbara 32.

I've had serious fuel contamination issues and was planning to install a plastic fuel tank while the engine is being swapped out for a secondhand Beta 28. However, the original tank is huge, about three foot long by three foot wide by two foot high, and it is seriously built in - it overlaps the engine bay by about four inches at each end and goes deep under the cockpit locker. The only way you could get it out would be by cutting it into sections - a major undertaking; way beyond my skill set and a very expensive job to have done, I suspect.

It looks well installed, is supported at both ends and suspended above the floor of the bay. I can see no external signs of rust. It has a small sump, but – and I think this may be where the contamination issues arise – the feed and return come out of the sump…

So my options seem to be drilling an access hole in the top or side of the tank, clean out the sludge (or have it done professionally), and then fit a new outlet on the side, above the bottom of the tank - or possibly a dipper tube from the top (which may require an additional pump), and just blank off the pipes to and from the sump. (Fitting from the top would also allow me to fit a fuel gauge.)

To complicate things, I can see from the filler that the tank is full of stainless steel mesh, presumably to stop sloshing – it looks a little like those stainless steel pan scrubbers. However I was able to move this aside with a cane, and would plan to remove as much as possible via the access hole that would be drilled.

it all sound a major undertaking, so if anyone has any bright ideas I would be most appreciative! Also if anyone knows a company that might be able to clean the tank in the Poole area (and possibly carry out the work).

Many thanks

 

[Rich the Scribbler]

I've also posted this as a new post in case this old thread isn't spotted.

 

[Tranona]

Suggest you contact here cpfuelpolishing.co.uk/about-us/ or here fuel-polishing-services.co.uk/contact/ to have the tank cleaned.

Drawing from a sump is normal, although there should also be a drain.

 

[NormanS]

Suggest you contact here cpfuelpolishing.co.uk/about-us/ or here fuel-polishing-services.co.uk/contact/ to have the tank cleaned.

Drawing from a sump is normal, although there should also be a drain.

Drawing fuel from a sump is nonsense. The sump is there to catch any water or dirt which would otherwise move around the base of the tank. The sump should have a means of draining it. The draw off pipe should be from a point above the base of the tank.

 

[38mess]

Drawing fuel from a sump is nonsense. The sump is there to catch any water or dirt which would otherwise move around the base of the tank. The sump should have a means of draining it. The draw off pipe should be from a point above the base of the tank.

Agreed.
My 40 yo SS fuel tank is in good condition. The fuel take of and return enter the top of the tank and they end about an inch from the bottom of the tank. The sump is only for trapping any water or debris. In ten years of ownership I have never seen any water in this.
A fuel take off from the sump is asking for problems. IMO

 

[vyv_cox]

The fuel take-off from my tank is from the bottom. There is an upstand on the fitting about an inch high whereas the drain plug is flush with the bottom. This has worked perfectly for 40 years.

 

[Tranona]

Drawing fuel from a sump is nonsense. The sump is there to catch any water or dirt which would otherwise move around the base of the tank. The sump should have a means of draining it. The draw off pipe should be from a point above the base of the ta

That may well be so and I agree, but it is still common to draw from the sump, probably with a short stack pipe as described by Vyv. The absence of a drain plug is worrying though.

 

[B27]

Drawing fuel from a sump is nonsense. The sump is there to catch any water or dirt which would otherwise move around the base of the tank. The sump should have a means of draining it. The draw off pipe should be from a point above the base of the tank.

Drawing fuel from a sump makes sense if you have filters adequate to cope with any amount of water and dirt you're designing for. It means that the tank is as clean as possible, with the minimum of water/diesel interaction.

Drawing fuel from anywhere above the bottom of the tank means you risk drawing air well before the tank is empty.
It also means enough water and gunk can lurk there until you really need the engine on a rough day, when it can clog many filters.

What's appropriate will be different according to whether we're talking about a small yacht with a 50 litre tank or a 'small ship' with big reserve tanks and a 'day tank' feeding the engine.

A lot of older small yachts from last century have a half-baked in between system, drawing from above the bottom, but nothing in place to easily deal with water. IMHO, a drain plug at the bottom is no good, a second dip tube into a corner of the tank which can be made 'the low corner' by heeling the boat is good for routine water removal/checking.

Cars mostly work for 20 years with just a couple of filter changes, they do that by drawing the diesel from the bottom of a sump. Boats need a bit more understanding of what your individual system is doing, and regular checking.

 

[NormanS]

Drawing fuel from a sump makes sense if you have filters adequate to cope with any amount of water and dirt you're designing for. It means that the tank is as clean as possible, with the minimum of water/diesel interaction.

Drawing fuel from anywhere above the bottom of the tank means you risk drawing air well before the tank is empty.
It also means enough water and gunk can lurk there until you really need the engine on a rough day, when it can clog many filters.

What's appropriate will be different according to whether we're talking about a small yacht with a 50 litre tank or a 'small ship' with big reserve tanks and a 'day tank' feeding the engine.

A lot of older small yachts from last century have a half-baked in between system, drawing from above the bottom, but nothing in place to easily deal with water. IMHO, a drain plug at the bottom is no good, a second dip tube into a corner of the tank which can be made 'the low corner' by heeling the boat is good for routine water removal/checking.

Cars mostly work for 20 years with just a couple of filter changes, they do that by drawing the diesel from the bottom of a sump. Boats need a bit more understanding of what your individual system is doing, and regular checking.

What's the point of having a sump and not using it to prevent water and dirt getting to the filters?
A properly designed tank will have a relatively small free bottom surface, and any dirt or water will automatically, with the movement of the boat, drop into the sump.
Boats are not cars.

 

[B27]

What's the point of having a sump and not using it to prevent water and dirt getting to the filters?
A properly designed tank will have a relatively small free bottom surface, and any dirt or water will automatically, with the movement of the boat, drop into the sump.
Boats are not cars.

The filter can be the best means of removing water and dirt.

Maybe if some boats learned a little from cars, we'd have a lot less threads about diesel bug.

 

[Rich the Scribbler]

Many thanks for all your comments, everyone, it's been really useful. In particular, many thanks to Tranona for suggesting CP Fuel Polishing of Poole. Carl, the owner, has been incredibly helpful - he popped straight round to take a look, and is coming back to drill a hole for a large inspection hatch. He will then clean out all the sludge and pressure wash the tank.

He is fitting a new inspection plate that includes a mounting for a fuel gauge sender and will also be fitting a dipper tube so that in future the take-off is above the bottom of the tank, rather than via the sump. That system may have worked in the old days, but this new biodiesel seems to be creating havoc for boat owners, and the sump will just collect sludge. I think it's almost certainly why the old engine wasn't able to pull enough fuel through.

 

[arcot]

Plastic fuel tanks ....fire hazard

 

[PeterV]

Diesel isn’t a fire hazard, if a fire melted a plastic diesel tank the diesel would probably put the fire out, as it did for magazine fires in warships during the Falklands war.

 

[geem]

What's the point of having a sump and not using it to prevent water and dirt getting to the filters?
A properly designed tank will have a relatively small free bottom surface, and any dirt or water will automatically, with the movement of the boat, drop into the sump.
Boats are not cars.

A sump can have a second benefit. If the pick up pipe is in the sump area, it reduces the risk of air being drawn into the pickup pipe when the tank is getting low and the boat is being bounced around.
A regular tank clean or drain from the sump should ensure there is not such a quantity of dirt/water in the sump that the filters can't cope.

 

[The Q]

A fuel tank filled with mesh is normally for petrol as a anti explosion/ fire reduction device. I've got a couple of "Explosafe" fuel cans with such a filling.

The filter can be the best means of removing water and dirt.

Maybe if some boats learned a little from cars, we'd have a lot less threads about diesel bug.

Cars generally don't sit around for weeks on end in a high humidity area. They generally use fuel, getting shaken and mixed up, drawn from the bottom of the tank, there by keeping the tank clean.
Your filter will just turn into a soggy mess if you have water in the fuel, many filters are paper based.

I built my own fuel polisher using a diesel lift pump ( 12V ) , demijon to collect the water, a fuel filter to collect debris, a long copper pipe to reach the bottom of the tank , and the necessary rubber hose . If I'm down working on the boat for the day I'll plug it in for an hour. Not much comes out these days unlike the first time i used it when there was a couple of gallons of water in there and some sludge.