How Do You Dip Your Tanks?

[valhalla360]

Originally Posted by Panope

Another reason to NOT have holes in bottom of tanks might be fire saftey. A fire that burns through a 'bottom of tank component' (like a hose) will then get a tanks worth of diesel to feed it.

I built my tanks with 'bottom of tank' fuel pick-ups and rubber hose. This is the worst arrangement for fire saftey because the tank valves are on (when the engine is running) for significant periods of time.

A future project is to change out the rubber hoses for fire resistant ones and also to rig remote shut-offs to my tank valves (just a pull cable).

Steve

Assuming metal tanks...there is a tiny bit of truth if you use plastic fittings.

Assuming fiberglass or plastic tanks...any fire that melts the fittings is likely going to melt or burn the tank. Even metal tanks are not likely to survive if the fiberglass hull gets going.

If you have a metal ball valve, not much risk of it melting if left closed when not in use.

Give the flat bottom tanks, a dip tube is not going to show the same as a sump. Over time any free water and most crud will tend to collect in the sump. With a typical flat bottom tank, it likely will be off in the corners where it can't be sampled or easily removed.

If the bottom fitting is really the issue, a sump without a fitting could be used and a doubled up dip tube used. A lower one (right to the bottom) that is used for sampling and sucking crud out and a second that draws fuel for the engine from a couple inches higher. Wouldn't cost much or be complex to setup but you need the sump already included.

[Juho]

I try to cure my paranoia by pumping a sample (less than a litre) from the bottom of the tank with the (factory made) manual pump at the beginning and end of each season. My theory is that if there was something wrong in the tank, I would see something in that sample. But I never do. The fuel looks like normal fuel with no dirt or water or anything. So, that cures the paranoia, except that a minor part of it is left since I didn't open the tank to fully check it out. The theory is that if I can't see it, the motor can't see it either .

The siphon problem could be a serious one, so it should be avoided. In my system the tube exits the tank at the top, and there (at the top of the tank) is a valve that is closed when the pump is not in use. One could also break the siphon by letting air in at the valve to be double sure, but I don't think my system does that.

I would appreciate also the clear circular covers of Kenomac, but probably will not install them since there have been no problems so far. If I'd sail to the south, then certainly something more (starting from a fuel cleaning system).

[kish]

Originally Posted by Dockhead

I am a bit anal-compulsive about fuel, and up to now I have always had my tank cleaned out every two years, religiously. It costs about $1000.

Now in all these years I've never found a drop of water or a speck of dirt in the tank. I'm careful about where I buy my fuel, and the fuel in Northern Europe is generally of very good quality.

This year it's time again, and I'm thinking it's a waste of $1000 (650 pounds) since I never find anything, and there is nothing to clean.

But I sure as hell am not just going to let it go. So I think about dipping the tank -- pulling up whatever is at the bottom of the tank and having a good look. I just can't quite figure out how to do it, practically. My single tank, holding about 700 liters or 2/3 of a ton of fuel, is very deep, more than a meter. It has a kind of sump, conveniently located just below the large inspection hatch. So I think I need some kind of long tube, maybe a copper one, but how to draw the fuel up into it? Maybe one of those outboard rubber bulb things?

Anyone have any useful experience they could share?


Unrelated topic, but how cool is it, what's happened to the price of fuel? I only buy it approximately twice a year, so I get out of touch. At the Cowes fuel barge, it's now down to 59 pence per litre! (Plus whatever duty you declare). That's only a bit more than half of what it was just a year or two ago. No longer will I have to take out a second mortgage to bunker the boat! Now under $1000 for a whole tank.


I'm hoping to bunker up in Russia again this year -- best fuel I ever bought, and for peanuts (from memory, 25 cents a liter or something like that). It was brought up to me in a tanker truck from St. Petersburg, and I tied up to the ruins of a wharf, bombed out in WWII and never rebuilt, to get close enough to the truck to take on the fuel. THAT was an adventure in itself. In the magical fortress city of Vyborg. Karelia. The fuel was so sweet, with such a high cetane number, that the sound of the engine was noticeably different. It was delivered with a certificate, and with a sample drawn off and sealed -- as if they were selling me fine wine. Coolest fuel buying experience of my cruising life.

Why not use a vacuum unit as sold to extract used lube oil from the engine sump, costing less than $50, allied to a copper tube 6 or 8 mm internal diameter or what ever will fit through a tank opening and go to the bottom possibly available via a dipstick opening or fuel gauge sender tank opening or fuel take off for a diesel heater.

The copper pipe, as used in microbore central heating systems, can be obtained from a plumber's merchant.
You could build a polishing system cheaply by searching eBay for a 12 volt "gear pump" for circa $100 and use a fuel filter of similar specification to your engine's primary fuel filter to pump out and circulate through filter and return.

Match the pump flow rate to the filter's flow rate.

Total cost an awful lot cheaper than $1000 every two years.

[RaymondR]

Originally Posted by Dockhead

But I don't want to polish the tank. I just want to draw off what's in the bottom.

I used to do this with a Finsbury engine oil extraction pump. The pump came with an internal thread into which a small copper tube screwed and an external thread onto which a 1/2" copper water pipe could be screwed using a nut and nylon olive type connection. It required a piece of 1/2" tube about a metre long to reach the bottom of the tank which is down in the keel but was very effective in sucking out the water and slime which occasionally collected there.

I still use the Finsbury but it is now permanently installed in parallel with a 12V gear pump. The Finsbury is used to prime the gear pump which then circulates the fuel tank bottoms through a large filter/water separator. I use the same system to pump the oil out of my engine for oil changes.

[Cheechako]

Originally Posted by Dockhead

A home-made on board polisher is a great thing, but does not replace a real professional scrub of the tank. The pros use a high pressure jet of fuel on a wand to really clean out the tank. If you have a good way of keeping every drop of water out of the sump of the tank (like what Jedi and Minaret have), then you might not need to clean the tanks all that often, but still it must be done from time to time.

As an alternative to the pro system, you could take all the fuel out of the tank and scrub it out by hand -- if you can get to it. That's not an option on my tank which is very large and deep, and only has one access hatch.

True .....but it will if you already had the pro polish done, it will keep them clean.

[RaymondR]

Found a photo.

The water trap thing has a felt bag filter inside it, it does not do very fine filtering but takes out all the visible particles from the fuel and separates out the water.

The line with the check valve allows to Finsbury to be bypassed once the gear pump takes suction.

The short section of rubber hose between the Finsbury and the water trap is removed and replaced with a hose when I want to pump out engine oil or empty the fuel tank.

The system works well and only cost a few hundred dollars.

The total lift from the bottom of the fuel tank to the Finsbury suction is about 1.25m so the system produces plenty of suction.

[socaldmax]

Originally Posted by a64pilot

Ideally you filter it and return to the tank, move the wand around like a vacuum, and I'd use a plastic tube.
I use a stick the measure fuel in aircraft tanks, I learned to make sure the stick was too long to accidentally get dropped into the tank. Imagine how I learned that?


Sent from my iPad Pro using Cruisers Sailing Forum

Is there a plane flying around out there that gets a "clunk" every time it banks?

LOL

I had a Jr High teacher that loved to tell us horror stories of his time as a factory worker at Ford. He said most of the workers then (must have been the late 60s) had such low morale they would drop their empty soda bottles into the door frames of the cars and he would weld them up. The door would rattle, but the bottle wasn't visible and couldn't be removed unless the door skin was removed. He was pretty remorseful over the thousands of cars driving around with a door rattle because of him and his coworkers.

He also made it a point to impress upon us how mind numbingly boring factory work was. I always pointed out how lucky he was to have us as his students. As opposed to teaching in Detroit or Chicago, for example. LOL

[a64pilot]

No I got it out, but I do think now about anything I put in a tank, that could be dropped.
I have aluminum tanks, and I won't get anywhere near them with copper, I have heard but do not know that copper will cause dissimilar metals corrosion in an aluminum tank, and can cause the tank to fail, I'm paranoid about those tanks anyway.
The plastic line, like what we use in our oil extraction pumps, I doubt that would ever cause a problem if I dropped a piece.
I did find a "bucking bar" in the wing of my 1946 Cessna, there is no telling how long it had been riding along in there.

Like someone else said, you already have an oil extraction system, and that sounds like the perfect thing to use here, and nothing to buy or store.



Sent from my iPad Pro using Cruisers Sailing Forum

[adlib2]

Originally Posted by Dockhead

I am a bit anal-compulsive about fuel, and up to now I have always had my tank cleaned out every two years, religiously. It costs about $1000.

Now in all these years I've never found a drop of water or a speck of dirt in the tank. I'm careful about where I buy my fuel, and the fuel in Northern Europe is generally of very good quality.

This year it's time again, and I'm thinking it's a waste of $1000 (650 pounds) since I never find anything, and there is nothing to clean.

But I sure as hell am not just going to let it go. So I think about dipping the tank -- pulling up whatever is at the bottom of the tank and having a good look. I just can't quite figure out how to do it, practically. My single tank, holding about 700 liters or 2/3 of a ton of fuel, is very deep, more than a meter. It has a kind of sump, conveniently located just below the large inspection hatch. So I think I need some kind of long tube, maybe a copper one, but how to draw the fuel up into it? Maybe one of those outboard rubber bulb things?

Anyone have any useful experience they could share?


Unrelated topic, but how cool is it, what's happened to the price of fuel? I only buy it approximately twice a year, so I get out of touch. At the Cowes fuel barge, it's now down to 59 pence per litre! (Plus whatever duty you declare). That's only a bit more than half of what it was just a year or two ago. No longer will I have to take out a second mortgage to bunker the boat! Now under $1000 for a whole tank.


I'm hoping to bunker up in Russia again this year -- best fuel I ever bought, and for peanuts (from memory, 25 cents a liter or something like that). It was brought up to me in a tanker truck from St. Petersburg, and I tied up to the ruins of a wharf, bombed out in WWII and never rebuilt, to get close enough to the truck to take on the fuel. THAT was an adventure in itself. In the magical fortress city of Vyborg. Karelia. The fuel was so sweet, with such a high cetane number, that the sound of the engine was noticeably different. It was delivered with a certificate, and with a sample drawn off and sealed -- as if they were selling me fine wine. Coolest fuel buying experience of my cruising life.

I've been using an O/B Motor Fuel Hose with a bulb for years to suck any debris out below the dipstick hole. By maneuvering it around inside the tank can cover a large area. Exhausted into a clear bottle or bucket can see if my efforts are worthwhile and when to stop. Never use biocide as I believe the bug skeletons cause more problems with sludge buildup, preferring to burn them through engine usage. Never have a problem with blocked filters, even in storms with low bunkers. I see Active Captain has a deal with Defender right now for fuel polishing units for $650. My O.B hose costs about $30.
Enjoy the cheap fuel and know that Canada is suffering because of it. My Canadian income is down more than 30% in $US terms, so I much prefer pay double or triple for fuel; after all I'm a sailor.

[adlib2]

Originally Posted by Dockhead

I am a bit anal-compulsive about fuel, and up to now I have always had my tank cleaned out every two years, religiously. It costs about $1000.

Now in all these years I've never found a drop of water or a speck of dirt in the tank. I'm careful about where I buy my fuel, and the fuel in Northern Europe is generally of very good quality.

This year it's time again, and I'm thinking it's a waste of $1000 (650 pounds) since I never find anything, and there is nothing to clean.

But I sure as hell am not just going to let it go. So I think about dipping the tank -- pulling up whatever is at the bottom of the tank and having a good look. I just can't quite figure out how to do it, practically. My single tank, holding about 700 liters or 2/3 of a ton of fuel, is very deep, more than a meter. It has a kind of sump, conveniently located just below the large inspection hatch. So I think I need some kind of long tube, maybe a copper one, but how to draw the fuel up into it? Maybe one of those outboard rubber bulb things?

Anyone have any useful experience they could share?


Unrelated topic, but how cool is it, what's happened to the price of fuel? I only buy it approximately twice a year, so I get out of touch. At the Cowes fuel barge, it's now down to 59 pence per litre! (Plus whatever duty you declare). That's only a bit more than half of what it was just a year or two ago. No longer will I have to take out a second mortgage to bunker the boat! Now under $1000 for a whole tank.


I'm hoping to bunker up in Russia again this year -- best fuel I ever bought, and for peanuts (from memory, 25 cents a liter or something like that). It was brought up to me in a tanker truck from St. Petersburg, and I tied up to the ruins of a wharf, bombed out in WWII and never rebuilt, to get close enough to the truck to take on the fuel. THAT was an adventure in itself. In the magical fortress city of Vyborg. Karelia. The fuel was so sweet, with such a high cetane number, that the sound of the engine was noticeably different. It was delivered with a certificate, and with a sample drawn off and sealed -- as if they were selling me fine wine. Coolest fuel buying experience of my cruising life.

I've been using an O/B Motor Fuel Hose with a bulb for years to suck any debris out below the dipstick hole. By maneuvering it around inside the tank can cover a large area. Exhausted into a clear bottle or bucket can see if my efforts are worthwhile and when to stop. Never use biocide as I believe the bug skeletons cause more problems with sludge buildup, preferring to burn them through engine usage. Never have a problem with blocked filters, even in storms with low bunkers. I see Active Captain has a deal with Defender right now for fuel polishing units for $650. My O.B hose costs about $30.
Enjoy the cheap fuel and know that Canada (Northern Arabia) is suffering because of it. My Canadian income is down more than 30% in $US terms, so I much prefer pay double or triple for fuel; after all I'm a sailor.

[Kenomac]

I needed to look this thread up for an interested Oyster 49 owner who now finds himself with tanks filled with contaminated fuel, so I thought I'd repost this link for review on this thread for anyone interested:
http://www.cruisersforum.com/forums/...on-132030.html

[hellosailor]

socald-
In the late 60's or 70's, when those Ford workers went on "job action", actually what they did was to put their empty glass soda bottle in the drive shafts before they popped on the universal joints and bolted 'em up. Eventually the bottles broke, leaving large amounts of ground glass in the shafts, which eventually chewed up the shafts from the inside out. Leaving total shaft failure and a disabled car.
As to the doors...One slow weekend I took the door panel off my '68 Mustang to see what was going "clunk" from time to time. I found a rather large ball joint tool sitting in the bottom of the door panel! Part of the same "We love our jobs and we're really happy about them!" actions.


But I remember working on a generally well made Pearson 32, rewiring, and discovering the electrics came in the starboard side of the cockpit (AC inlet) and the water fill was on the port side midships. Then they each ran under the companionway, crossed, and continued to opposite sides of the boat!! The only thing I could figure, the only reason to bring everything in and CROSS IT so inconveniently, was "them Pearson boys, they musta had one hell of a party on Friday, and come Monday morning, lookit that, they found the boat was all done!"


Sometimes, you know, you just have to wonder.