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11-06-2010, 01:51 PM
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#1
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Lieutenant
Join Date: Jan 2005
Posts: 97
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I have never had problems with dirty fuel and change primary and secondary filters at 250 hrs The tank (integral with the fin so at a fairly steady temperature) has not been cleaned in 5 years, holds 2000 litres and I run it down to about 1200 litres then refill
However, I have just had a test done on the diesel in the tank (by a tank cleaning/diesel polishing company, so they may be biased) here in Trinidad, and it says clean near the top, dirty midway and at the bottom, and recommend a full cleaning of everything, costing about £1000 or US$1500
How often do you have the diesel tank cleaned and is it worthwhile
Starbrite claim their Startron Tank Cleaner "will clean tanks better than any tank cleaning service" Does anyone have any experience of this product.
There are two access plate near the tank bottom in the side of the fin. If I remove them, what material is best for the replacement gasket (ie diesel and seawater proof)
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11-06-2010, 06:37 PM
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#2
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Admiral
Join Date: Jul 2004
Posts: 2,098
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First, your experience with test results don't surprise me, sound fairly typical. Our fuel didn't come up terribly dirty until we were in a nasty 5 days to windward in 20 to 30 knots, short miserably choppy seas. Just what shakes up the fuel tank to dislodge the gunk adhering to the sides and lying like a carpet at the bottom of the tank.
However, my natural cynicism says that those who are in the tank cleaning business have a serious interest in finding fuel tanks that are dirty. That's a lot of money to pay for tank cleaning, though I believe it would be about that much in the States. I'm not sure you need to pay somebody to do that, though. First thing to do is take your own sample of fuel from the bottom of the tank to see for yourself just what it looks like. If there are lots of chunks of gunk plus water, it's more than moderately dirty.
Here's what we did when our tank and fuel turned up dirty in Borneo with no facilities to help us. Dirty fuel was a problem for us because (a) we were in the topics full-time, so algae and wee beasties grew rapidly in the tropical warmth, and ( because we didn't use very much fuel, so too often the fuel had started to degrade from sitting anyway.
We first pumped out some of the fuel from the very bottom of our tank after we had been sitting at anchor for several days. The first sampling was pumped into a glass bottle, so we knew that the fuel water and dirt contamination was nasty. The rest of the diesel (well, most of it, taken from the very bottom of the tank) was pumped into relatively translucent 5-gallon jugs (the local/whatever had them, they had originally contained glacial acetic acid - clear enough that we could tell the different colors of the diesel. We let that diesel sit and settle for a day, then siphoned off the top 2/3s of it into clean jugs. We combined the dirty dregs into one jug, let that settle, tested to see if the top of it was clean, siphoned off the clean diesel as best we could. The very bottom of the fuel jugs contained water, then very, very dirty fuel. We discarded the dirty dregs responsibly (I'm really not sure if we asked the marina to get rid of it, if we burned it, or what).
The jugs with "clean" fuel we put back into the tank through a filter to remove as much of the final dirt as possible.
We then did it all over again after agitating the fuel tank (through the inspection port.) The second go-around the fuel wasn't nearly as dirty, though some big chunks of dirt/algae/whatever did come through, and most of the water from the bottom of the tank had been taken up the first time so this was a relatively easier and faster process.
Lots of work, but we didn't have access to enough fuel filters to do it as some others have done, which is to circulate the fuel in the tank with a pump through several fuel filters, starting with 30 micron, on down to 2 micron. I.e., pump it out of the tank with several fuel filters in line with the input end of the hose back into the fuel tank. I understand this takes many hours. It would be an easier way to do it.
Our method was because we didn't have the filters and capability of running pumping it through and around - no shore power to keep the batteries charged to run the pump for a day or so.
If you take a test sampling from the bottom of the tank, you might want to settle out the worst of the water and gunk rather than waste several fuel filters to take care of the worst of the contamination. If you don't agitate the fuel in the tank you might not get an accurate indication of how dirty the tank is.
Gah! I hope the cleaning service was exaggerating and you can get away with simply recirculating the fuel through some filters for a day or so.
Then come over tho the Tavern and have a few pints on me.
Jeanne
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11-07-2010, 12:31 AM
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#3
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Ensign
Join Date: Nov 2010
Home Port: Nuuk
Vessel Name: La Gitana
Posts: 16
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Just had to clean our two 800 litre tanks last month. The cost in Canada is in line with what they are asking in Trinidad. First they suction the remaining fuel out - ours were down to less than 100 litres each. Then the put in some sort of cleansing agent and suctioned that out and rinsed with kerosene and suctioned that back out.. We don't have an algae problem, but the kerosene would have killed it anyway. Then pulled all the fuel water filters and replaced them with 20 micron, 10 micron and 3 micron in line. Replaced the engine filters 10 and 3 microns at the same time. Changed the oil to full synthetic and oil filters too.
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Capt Abraham
La Gitana
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11-08-2010, 01:36 AM
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#4
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Commander
Join Date: Jul 2009
Home Port: St. Augustine FL
Vessel Name: Linnupesa
Posts: 189
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Quote:
Originally Posted by steelfan
I have never had problems with dirty fuel and change primary and secondary filters at 250 hrs The tank (integral with the fin so at a fairly steady temperature) has not been cleaned in 5 years, holds 2000 litres and I run it down to about 1200 litres then refill
However, I have just had a test done on the diesel in the tank (by a tank cleaning/diesel polishing company, so they may be biased) here in Trinidad, and it says clean near the top, dirty midway and at the bottom, and recommend a full cleaning of everything, costing about £1000 or US$1500
How often do you have the diesel tank cleaned and is it worthwhile
Starbrite claim their Startron Tank Cleaner "will clean tanks better than any tank cleaning service" Does anyone have any experience of this product.
There are two access plate near the tank bottom in the side of the fin. If I remove them, what material is best for the replacement gasket (ie diesel and seawater proof)
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Reefhunter, here's another take on the fuel cleaning issue using the old 80/20 rule:
Let's assume the poor fuel generally settles out at a lower level because of a slightly higher specific gravity. But, instead of getting a full tank cleaning, just aim at cleaning the very worst bottom levels and don't fret about the higher levels at all. You WILL get rid of most of the water and thereby deprive the gunkster bacteria of their livelihood. Plus, you will likely catch most of the settled gunk, and asphalt as well, but with far less effort.
With a 150g tank you'd need six 5g jugs to hold 20% of capacity, yet chances are ( other posts ) you don't even have a full 5g jug of reject fuel in your tank. With the fuel well settled so the garbage will have had a chance to sink to the bottom, siphon or pump out through a tube wand with hose attached as much of the tank bottom as you can reach through whatever access you can create. Let that decanted stuff settle out for several days if possible, as any layers will become defined better. Then decant and filter the acceptable fraction for return back into the tank.
This is basically the "decant into containers, let settle, then separate" routine already described by others, but you'd need to do it on only the worst fraction of the fuel. This saves a lot of superfluous busy work and zeros in directly on the problem. After all, your fuel pick-up pipe hangs directly in this zone, just above the tank bottom. Any filtering you can or want to do is of course also fine, but can be overkill IMHO if you have already cleared the 80% part of the problem. Your regular water/diesel filter also should do some work and will clean the rest quite adequately. Using a clear hose while pumping out helps, as you can gauge the clarity of the diesel as you go. Most plastics go brittle after tasting diesel, so a short glass sight tube with a fuel-rated hose would be ideal. ( It's what I use)
The fuel cleaning services are really good at vacuuming out your wallet as a non-featured side effect. Given a boat-buck I'd rather buy fresh fuel with it than futz around with a "big noise but no steam" process. Sure, they will get the tank walls much cleaner but unless chunks of stuff are actually in suspension a little crud sticking to the tank walls does no harm. That's why you have a dedicated filter after all, don't you?
As to the gaskets, rubberised cork is likely the best and cheapest cost/benefit wise. It has good spring-back characteristics and is quite fuel resistant, seen it's wide use in auto gasket cover/sump applications. Hopefully salt water is a minor issue in your bilge and if not then the fuel seepage problem will pale by comparison. As suppliers Grainger and McMasterCarr and Auto suppliers come to mind.
Buna (Butyl?) rubber, N-type, nitrile and viton are almost universal gasket materials but may not have enough 'flex and give' to seal a less than perfectly flat sealing lip. Cork is much better at adapting to shape and per thickness is a lot cheaper than buna-N . A rough fibreglass cut-out will be much better served with cork.
Ivo
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11-08-2010, 09:04 AM
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#5
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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On boats I have limited experience in cleaning out tanks for dirt and gunk. Diesel on the other hand I have lots of experience with (Got to love Uncle Sam and equipment breaking down in the field). Since military vehicles go over so much different stuff that agitates the tanks heavily, you would think that they get clean often to cut down on bacterial growth and such, nope. We used two in-line filters and you keep an eye to let the water that accumulates out of the trap. As far as the tank cleaning folks, not sure I see a big reason to go that route. Jeanne, points out that a lot of it you can do yourself, also remember that the more filters you put in line the more suction or pressure the pump as to generate to move the fuel. Now if you have a pump that is up to the job no problem, but I would check first. I have seen pumps not able to generate the need pressure for a higher filter level, it took forever to track down why no fuel was getting to the engine. I will ask my father-in-law his opinion and suggestions, as he has over 30 yrs working on over the road diesel engines as well as industrial generator sets (hospital grade and such). He might know a few ways to clean a tank and how to keep it clean that might be of interest to all of us. I know in the Military that all the tanks in my day where drawn from the bottom sot that everything would get pulled through the filters and not settle into layers where you where only using the top and getting a nasty mess on the bottom. Will get back once I get an answer from him. Michael
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11-08-2010, 05:19 PM
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#6
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Ensign
Join Date: Nov 2010
Home Port: Nuuk
Vessel Name: La Gitana
Posts: 16
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Quote:
Originally Posted by chiroeurope
On boats I have limited experience in cleaning out tanks for dirt and gunk. Diesel on the other hand I have lots of experience with (Got to love Uncle Sam and equipment breaking down in the field). Since military vehicles go over so much different stuff that agitates the tanks heavily, you would think that they get clean often to cut down on bacterial growth and such, nope. We used two in-line filters and you keep an eye to let the water that accumulates out of the trap. As far as the tank cleaning folks, not sure I see a big reason to go that route. Jeanne, points out that a lot of it you can do yourself, also remember that the more filters you put in line the more suction or pressure the pump as to generate to move the fuel. Now if you have a pump that is up to the job no problem, but I would check first. I have seen pumps not able to generate the need pressure for a higher filter level, it took forever to track down why no fuel was getting to the engine. I will ask my father-in-law his opinion and suggestions, as he has over 30 yrs working on over the road diesel engines as well as industrial generator sets (hospital grade and such). He might know a few ways to clean a tank and how to keep it clean that might be of interest to all of us. I know in the Military that all the tanks in my day where drawn from the bottom sot that everything would get pulled through the filters and not settle into layers where you where only using the top and getting a nasty mess on the bottom. Will get back once I get an answer from him. Michael
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I come from the same route - military trucks. Don't remember dropping more than five fuel bladders in fifteen years to clean them out. Most of our problems were dirt and water related. I already installed multiple inline filters to prevent it from occurring and an extra lift-pump. She's a knockout Gulet at 21m! On next haulout - we're adding a third tank and taking out a 400l water tank for a watermaker.
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Capt Abraham
La Gitana
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11-16-2010, 07:17 PM
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#7
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Okay,
Talked with my father-in-law and got some interesting answers. First is if the tank is dirty empty as possible to the bottom (completely). This evolves doing so that that you can let the fuel settle to git rid of the junk in it. Next open the access panel and use Verasol or a cleaner of the same type (algeacide/bateriacide). Then insure that the fuel system draws from the lowest point possible in the tank that will normally remain covered with fuel or use a pump that can handle air if needed ( this will help remove the problem of water and gunk in the tank on a more long term basis).
Put a water trap in line from the tank to the pump if possible. More than one water trap would be a good thing. Polishing fuel down to 10 micron is good for all tanks new or old. On newer engines you need to polish down to 5 micron minimum as the tolerance for the injectors has gotten a lot tighter. 3 micron will add to the life of newer engines though you do have to make sure the fuel pump on the high pressure and low pressure can provide the needed pressure to keep even flow. Also remember that with smaller micron filters that a very high quality in line water trap is required not an option and MUST be checked on a daily basis if possible.
I hope this helps. It was a very interesting discussion with my father in law and got a bit more information then asked but learned and enjoyed which is the important part anyway.
Fairwinds,
Michael
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What you see in the Universe, sees you.
MM6WMU
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11-17-2010, 03:16 AM
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#8
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Admiral
Join Date: Oct 2004
Posts: 3,067
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Always thought it was a good idea to filter fuel BEFORE putting it into the boat's tank/s - especially when getting it from questionable sources whilst cruising. Here is one such filter :-
C L I C K
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05-22-2011, 09:19 PM
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#9
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Lieutenant
Join Date: Feb 2011
Home Port: Georgetown
Vessel Name: Surprise
Posts: 63
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We are buying a boat that has been sitting inside for 3 years - may have been put in once or twice to be tested/surveyed but I certainly doubt there has been any real maintenance on it for at least 3 years.
This discussion makes me wonder if it would be best to just pump out whatever is in the tanks before trying to run the engine for any length of time?
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Now, bring me that Horizon!
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05-23-2011, 02:45 AM
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#10
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Rear Admiral
Join Date: Aug 2010
Posts: 218
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Quote:
Originally Posted by CaptDinghy
We are buying a boat that has been sitting inside for 3 years - may have been put in once or twice to be tested/surveyed but I certainly doubt there has been any real maintenance on it for at least 3 years.
This discussion makes me wonder if it would be best to just pump out whatever is in the tanks before trying to run the engine for any length of time?
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Gooday y'all. Attention - Bob, Robin & Co. & everyone else also. We'll all learn from the associated comments - I'm sure. Many thanks JeanneP, you've forgotten more than most of us will ever learn - but we still trying, so Thanks ! Keep shariang your wisdom ! ! RICHARD - RIGHT ON ! ! Better to navigate with knowledge than learn how to swim off the rocks even with safety ! To B,R & Co - suggest you follow your inner vioce; Don't start enging before; 1/ empty tank & clean out thoroughly 2/ change all filters & add more if necessary including all fuel lines & connections & fittings 3/ Use fresh fuel as the danger of 're-cyling' old fuel is never worth - the calamity, a collision with anything & doesn't cost near as much as the inevitable expensive repairs. IMHO Catious foresight beats hard earned tears of regret in hindsight - every time & I've gone the hard way. ie. good fire-pervention systems, progremmes & practice beats the biggest fire extinguisher in the hands of a very frightened crew - hands down & cost a lot less too - also learned the hard way. (but not on my yacht) The very best practices' are only just enough when the chips are called in for full payment.
As always, wishing you the best, cioa, james PS. Dirty, old fuel has stopped the biggest 2 cyl Lister diesel pump I've ever owned. It's 6' tall & I still can't get it to work. All avoidable drama. Darn & golly-gosh. 'jj-geri-hat-trick'
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05-24-2011, 01:22 AM
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#12
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Lieutenant
Join Date: Feb 2011
Home Port: Georgetown
Vessel Name: Surprise
Posts: 63
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"Don't start the engine quite yet."
We will get the yard to drain the tank, clean it and refill with fresh fuel. We will install fresh filters and do a few more prep items prior to giving the engine a turn - a few ounces of prevention, as it were!
Many thanks!
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Now, bring me that Horizon!
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05-25-2011, 06:35 AM
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#13
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Rear Admiral
Join Date: Aug 2010
Posts: 218
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[QUOTE=CaptDinghy;1306200156]
"Don't start the engine quite yet."
We will get the yard to drain the tank, clean it and refill with fresh fuel. We will install fresh filters and do a few more prep items prior to giving the engine a turn - a few ounces of prevention, as it were!
Gooday y'all. Bob & Robin do take some time (I got lost in there for 6 hours over 3 days) to follow 'JeanneP)'s lead & go into her suggested 'wilki' hilighted site. My 'gawd' I could spend another 40 hours - at least - and learn ever so much. THANKS YOU, 'JeanneP' so very much. Don't forget to get the 'yard' to blow-out all the pipes & hoses. Much 'gunk' can lie in there. More 'ounces of - etc. Ciao, james
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