Fuel Tank Cleaning

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Tom.B

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Joined
Jul 30, 2009
Messages
5,839
Location
USA
Vessel Name
Skinny Dippin'
Vessel Make
Navigator 4200 Classic
It's time to start researching the process of cleaning Skinny Dippin's fuel tanks. I'm fairly sure they are gunked up, and while I am getting low on fuel, I am considering the project.

There are two fuel cells directly port and starboard of the single Perkins 6.354M. Both tanks have round inspection plates on the SIDE facing the engine and are about 12" in diameter with a dozen or so nuts holding them on. Not the easiest place to get to, but I might can make it work. I also have a fuel scrubbing system with a 1/4hp 60gph pump (for sure I will be able to xfer fuel from tank to tank... which is nice).

So, here are my initial questions:

1) What should I expect to find in there?

2) What supplies do I need to get to prep for the job? Scrapers, buckets, gloves, respirators, cleaners, shop-vac? Is this going to be a toxic job?

3) My most pressing question is how to seal the inspection plates after removal and what sealant should I use? A poor choice here will cause a major fuel spill and I won't find out about it until I goto fill the tanks. By then, it will be too late, so I need to get it right the FIRST time.

4) I wonder if I can utilize my scrubber pump to blast the inside of the tanks and knock off some of the build-up BEFORE I pull the inspection plates. I would just set it up with a bendable wand that I could direct the flow around the inside of the tank. However, I don't know if there are baffles that would block that process.

5) As a follow-up to #4, what if there are areas I can't reach? It's only a 12" hole (maybe) and I don't think Inch High Private Eye is in the diesel biz. Can I use a power washer as long as I thoroughly dry it afterwards?

That's it for now, but I'm sure there will be more later. Thanks y'all!

Tom-

*PS* Picture of scrubbing pump attached to only show that tapping into the system would not be that hard.
 

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Gonzo

If you were to install a Fleetguard*30u spin on filter in front of your existing filters, maybe cleaning your tanks during normal operation via your polishing*setup and the new filter would suffice.

Provided your tank baffles don't hamper the effort, steam cleaning with removal of the loosened sludge via* hand scoops is how I have seen it done. The tank must be empty of course to accomplish. Use a bunaN or other diesel compatible gasket to reseal. But first, dip your tanks to be sure you have enough gunk to justify opening up the tanks.
 
sunchaser wrote:
Gonzo

Provided your tank baffles don't hamper the effort, steam cleaning with removal of the loosened sludge via* hand scoops is how I have seen it done. The tank must be empty of course to accomplish. Use a bunaN or other diesel compatible gasket to reseal. But first, dip your tanks to be sure you have enough gunk to justify opening up the tanks.
*Yes, Buna (NBR) and Viton are diesel comapable. Silicone and EPDM**are NOT.
 
It's a messy job! I'd encourage you to let the wife do it....
biggrin.gif


Julie helped me pulled the tanks and then she cleaned, sanded, epoxy coated and painted them.
 

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Dip the tanks?
 
Since I am in the yachting capital of the US we have a few companies here that do fuel tank cleaning. (not to be confused with fuel polishing). They use fuel to clean the tanks! The general procedure is to pump fuel out of one tank until it is almost empty, then spray the remaining fuel back in under high pressure with wands bent to different angles after running through a Racor filter. The spray loosens the algae and crud on the sides and bottom, it gets pumped out, cleaned in the filter and then pumped back in.
For boats with black iron tanks this will remove any water sitting in the bottom and should be done to prevent rusting from the inside.
 
Anode wrote:
It's a messy job! I'd encourage you to let the wife do it....
biggrin.gif


Julie helped me pulled the tanks and then she cleaned, sanded, epoxy coated and painted them.
*Does she contract out? Julie did an awesome job.
 
The problem, Tucker, is that I don't know the status or existence of baffles.
 
Thanks jleonard! She is a trooper. Unfortunately she is also a college prof and had to start back to work today. Before she left she stripped all the floors with a heat gun, sanded and sealed them. She's wanting to get the coated this weekend. Floors are solid 1/2 inch teak planks and does it ever look nice.
Tom - Listen to Tucker. You don't want to introduce water into the system. Disposing of of the contaminated water would be cost prohibitive. Clean and filter with fuel. The end product will be usable to you (or someone). I know a sailboater who loads up with this 'cleaned' fuel every year before going south.
Several years ago I pulled a black iron fuel tank out of my sailboat. It was so yucky I took it to a big commercial radiator shop and danged if it didn't fit into their dip tank. I got a call the next day and the guy said 'I got good and bad news'.....'your tank is clean but it leaks'. You could put a light in it and see hundreds of tiny pin holes. It never leaked before and looked great from the outside. Don't buy into 'they only rust from the outside in'. I had to fabricate a new tank. Keep us informed of your progress.
 
Tucker,

*

I am so glad someone else nows the difference in cleaning a tank and polishing the fuel! I had a customer this morning* and when* I asked " you want the fuel pumped out (bad gas) or the tank cleaned" - he gets a very confused look and said "what's the difference" ... To polish the fuel and not clean the tank is like putting the baby back in the dirty diaper!

*

We clean thousands of tanks, from 10 gallons tanks to 30k gallon tanks and take the same approach everytime, get to the bottom of the tank*and agitate the HE77 out of it.

Cheap work ain't Good and Good work ain't Cheap.
 
If anyone here knows the difference between polishing and cleaning a tank, it's me... :-D

I only mentioned using water because I have a lowest point tank exit and could easily remove water. What I didn't think of is disposing of large amounts of it. Good call. Still, with baffles, I'm going to have to try and try and blast it off with a stream of fuel thru the access panel and not thru the filler tube. However, will a Racor 500 be too small of a filter? I will likely be scraping first and hitting with a fuel stream only if needed. I still don't know what I will find in there when I open the panel.

What other supplies might I need?

Tom-
 
Tom,*

*

We've cut the tanks out of 4 boats and replaced them this summer due to leaks. One was a 37' Lord Nelson Victory Tug (I am sure you remember "Elizabeth Noble") a 41' Diesel formula, a 37' Gas formula, and a 50' Sailboat. All of them had multiple baffles. I also spent my fair share of hours cleaning tanks and polishing fuel to pay the bills, to do a proper job on a larger tank, I usually had to cut multiple access ports in the tank to do a really good job. From what I remember of the size and placement of your tanks, you are probably going to have at least 3-4 baffles welded on the inside of the tank that will come with in a couple inches or less from the top and bottom of the tank....lots of oil soaks, gloves, tyvek suits, fans, trash bags, safety glasses, respirator, scrapers, and a tarp or two are required for a good time.*

*

Also, as an extra precaution, even on diesel boats, I have my guys drain the tank as much as possible and put dry ice in the tank to push the fumes out before cutting into it, wether they are cutting the tank out or simply cutting an access port. Probably overkill on diesel, but required on gas!*
 
Oh yeah, I used a long bendable piece of 1/4" copper tubing with the end crimped down so barely open hooked to hoses and a 120V 1900gph pump to really spray the sides of the tanks. If careful you could bend it many times and many angles before it became useless
 
"The spray loosens the algae and crud on the sides and bottom, it gets pumped out, cleaned in the filter and then pumped back in."

AS noted this can frequently be a waste of effort and ca$h as the baffles of a large tank will hold gunk where an undirected spray has no chance of removing.

Its not worth the effort if 20 - 30% is still left as it will plug the filters when the boat gets roughed up.

IF you can reach the low point of the tank thru the opening , I would not fear a water power wash , though I would bail to dry and stick a shop vac hose in to BLOW , after you have the internals as dry as you can , and let it run for hours

A 10 inch hole might take a small fan to circ the air.

IF the tank has a real low spot (pray) it would be easy to put a hole in the top of the tank and install a 1/2 or 3/4 line as close to the bottom as you can and pump the bottom a day or two after each fuel fill , and if you ever use a fuel product that de emulsifies the water , so you can grab it..
 
This is beginning to sound like a job that isn't going to be much fun or that I might not be too successful in undertaking on my own. *sigh*
 
GonzoF1 wrote:
This is beginning to sound like a job that isn't going to be much fun or that I might not be too successful in undertaking on my own. *sigh*
*Tom,

It doesn't sound like a lot of fun does it? However, you can always open the inspection ports for a look. Then you will know a lot more than you do now.

FYI: I bought fuel-resistant gasket material from McMaster-Carr. It's a good idea to have it on hand before disturbing the inspection plates in case you need to close them up again straight away. You will also need a punch similar to these. Other forum members can probably shed light on the advisability of using a sealant with this material.
 
You say you're pretty sure your tanks have gunk in them. Ok. But does it create a problem? I mean you built a pretty elaborate fuel polishing system not so long ago. Did you have any problem runing the boat since? My point is even if you have gunk in your tanks (most tanks on our boats do by the way), if it's not creating any problem, why go through all this trouble and expenses? Looks like a solution to a non existent problem to me. But if you FEEL like doing it, that's an entire different thing I guess. But by the suggestions I read here, looks like a hell of a job. I'd make really sure it's worth all the efforts before cutting holes in my tanks to pressure wash the interior... And besides, even if I do 99% of the work on my boat, I still think some jobs are better left to professionals. This looks like a perfect example to me. Just sayin.
 
Gonzo

I remain a broken record on this subject - consider a 3 stage filter setup with an oversize spin on Fleetguard up front. Your 500 racor could serve as the 2nd step - 30u, 10u and on engine. Your crud problems, if they are as Fotoman suggests, *will be go away.

Dip (go through a deck fill with a small hose and suck out a sample from a few different levels) your tanks to see the nature of the problem.

*


-- Edited by sunchaser on Thursday 18th of August 2011 08:34:30 AM
 
download.spark
I have a agree with the last 2 posts. When I bought this boat 5 years ago, I was getting shut down every 6 to 8 running hours on my maiden delivery voyage due to fuel restriction.

Once at my home port I borrowed a polishing rig from a friend and filtered all my fuel. I had half tanks so one into the other, then all back to the empty tank. I only had one top inspection port per tank and I could not see any crud buildup. I wiggled my suction hose/fitting assembly all around the tank and under baffles as much as I could. I did not feel any sludge, nor did the end fitting show any signs of such.

I then changed to a multistage filter set up. First a Racor 900 at 30 micron, then the dual Racor 500 at 10 micron, then on to the engine (which I believe is 7 micron).

I have had zero readings on my vacuum gages since. I change filters once per season, but only because I feel bad if I don't.

Here is a pic of my change earlier this year...with 2 years on the 30 micron element.

*
 
FF says may not be worth it if 20% to 30% of the crud is left, but that means to me that 70% to 80% has been removed. Crud and algae in the tanks usually is not a big problem until it gets rough and the stuff is stirred up and drawn into your filters. Of course that is the worst time to have to get in the ER and change them! a major plus is to get out any water that has collected at the bottom of the tank. One of my tank cleaning guys showed to me an empty aluminum fuel tank with obvious corrosion on a few spots on the bottom where water had been sitting.
 
This photo is of a customers fuel tank where we had to cut holes in order to clean the tanks. His issues were that when he got under way the port engine would shut down. A 62' vessel with two hugh Detroits, four fuel tanks and a fuel problem. I am showing the inside of the problematic tank before we started cleaning, notice no crud hanging on the walls or pickup tubes.

*
 

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So you didn't have to clean it?
 
I had a friend with an intermittent problem of the engines shutting down at times when drawing from a particular tank.* After much money and time, it was found that a piece of cloth had come off a cleaning rag when the tank was built.* It would at times work it's way up the pick up tube to a place where it narrowed and then stopped the flow.* When the engines stopped it would fall back down and not cause a problem for a few days.* It was very frustrating for all concerned.
 
GonzoF1 wrote:
So you didn't have to clean it?
The point is the crud WAS not hanging on the wall but on the bottom of the tank. This is so typical of the interior of aluminum fuel tanks.

We did have to clean the tank, this was the problematic tank that kept clogging his racor. The trash/crud we removed from the bottom of the tank was very severe. As I posted earlier, you have to get to the bottom of the tanks and agitate the HE77 out of the 'growth'.
 
GonzoF1 wrote:
It's time to start researching the process of cleaning Skinny Dippin's fuel tanks. I'm fairly sure they are gunked up, and while I am getting low on fuel, I am considering the project.

There are two fuel cells directly port and starboard of the single Perkins 6.354M. Both tanks have round inspection plates on the SIDE facing the engine and are about 12" in diameter with a dozen or so nuts holding them on. Not the easiest place to get to, but I might can make it work. I also have a fuel scrubbing system with a 1/4hp 60gph pump (for sure I will be able to xfer fuel from tank to tank... which is nice).

So, here are my initial questions:

1) What should I expect to find in there?

2) What supplies do I need to get to prep for the job? Scrapers, buckets, gloves, respirators, cleaners, shop-vac? Is this going to be a toxic job?

3) My most pressing question is how to seal the inspection plates after removal and what sealant should I use? A poor choice here will cause a major fuel spill and I won't find out about it until I goto fill the tanks. By then, it will be too late, so I need to get it right the FIRST time.

4) I wonder if I can utilize my scrubber pump to blast the inside of the tanks and knock off some of the build-up BEFORE I pull the inspection plates. I would just set it up with a bendable wand that I could direct the flow around the inside of the tank. However, I don't know if there are baffles that would block that process.

5) As a follow-up to #4, what if there are areas I can't reach? It's only a 12" hole (maybe) and I don't think Inch High Private Eye is in the diesel biz. Can I use a power washer as long as I thoroughly dry it afterwards?

That's it for now, but I'm sure there will be more later. Thanks y'all!

Tom-

*PS* Picture of scrubbing pump attached to only show that tapping into the system would not be that hard.

Tom

May I suggest you closely review most portions of Soltron fuel additives website http://www.soltron-gtr.com/english.htm *Via searching, there are other good sites about Soltron.* It keeps tank insides, fuel in the tanks and fuel lines consistently clean.* My filters and the gas in the filters is checked every 50 hours operation.* I pour the gas into large glass container each time and due to no particles or discoloration I pour it back into the filter or into a new filter and carry on.* Soltron is highly recommended for diesel and gasoline.* In my opinion, discussion with other boaters, and from practical experience, the best, most inclusive 24/7 ongoing process to clean fuel tanks, fuel and fuel lines and to keep em clean is to use Soltron.*

For initial clean out: Filters should be checked every few hours operation.* I found my filters full of junk with vile color gas during first four close schedule filter changes... then for next few checkups the junk in filters diminished and gas color cleared.* Within short time after the fuel became very clear and has remained so.* Soltron actually turns the in-tank build up into a liquid combustion product and it gets burned as fuel.* Luckily my aluminum tanks are in stellar condition and werent too gummed up... no seepage holes became apparent after internal cleaning with Soltron.

A Word of Caution: If you have old tanks that may have porous areas or splits that the gunk is currently keeping sealed, and will need repair once cleaning is completed, then Soltron may not be the way you should clean them out.* I appreciate and trust Soltron!* Inexpensive too... minimal amount required at fill ups.* Its sold on the web, Napa auto stores, and other locations.

Good Luck and Happy Boating - Art **

*
 
"Of course that is the worst time to have to get in the ER and change them! "

And since hose is an accepted hook up to fuel systems , why have then in the engine room?

Someplace low where gravity will refill after changing and easy to get to is not THAT hard to find.
 
Hmmmm... A lot to think about. I suppose that the first thing really needs to be to probe into the tanks thru the filler cap and see if there is a need to step up to pulling off the inspection plate. I don't really know for sure that my tanks are gunked up. I only suspect it because I find myself changing filters pretty often. I don't have any point-of-reference for what a clogged filter looks like or when to change it (I usually change them when the idle can't hold at a steady rpm). I suspect that a vacuum gauge at the small pressures I am dealing with here would be about useless. The gauge just doesn't seem that accurate, but again... no point of reference. I hardly understand what is going on with the gauge on the high pressure scrubbing filter. However, if y'all think it will help, I will get one for the primary Racor 500 too.

Is there an online service for fuel sample analysis? Moreover, anyone know of one in Eastern NC? Would something like that even help understand what is going on in there?

Thanks for the replies so far!
Tom-
 
Put a gauge on the Racor for reference. Open up the tank, try to get a visual and sample off the bottom. Local oil jobbers in your area should be able to analys the sample for you.
You may be sucking some air before your filters get loaded up. A 30 micron Racor 500 filter will have some visable gunk on it when it's plugged.
Report back.
 
If you haven't found these before do yourself a favour and read them. The first is from Boatdiesel Articles (www.boatdiesel.com), the second from Seaboard Marine (www.sbmar.com)

http://boatdiesel.com/Articles/Articles.cfm?P=20060110_Introduction.cfm&Y=2006

http://www.sbmar.com/Articles/MarineFuel-Filtration_Introduction.php

Both are written by Tony Athens and are excellent information.

At least read them.

I know you built and installed your polishing system and are concerned with dirty tanks.* I've not had to do mine but have seen what several people have had to do in their boats and it was a big job, of course do-able.

Many people have followed Tony's suggestions and have avoided major problems with dirty fuel reaching the engines and the consequent expense and shutdowns.*

*You may still wish to open and clean the tanks but consider adding filters first, LARGE filters, with lots of crud capacity.*They are cheap.* Even if you* go for the cleaning the extra filter capacity will protect you and give piece of mind.

If water is the concern then while the fuel is down it may be worthwhile emptying the tank and installing a drain or a diptube so water can be removed from time to time.

*A polishing system* will help clean fuel overall* but won't protect the engine if you get a slug of crud and then run soon after, which for most of us is the case.*

Many boats have itty bitty filters that will flow the engines required fuel but have very little dirt or water holding capacity.*** You can install a large crud collector ahead of the existing setup and help you system out overall a lot which is suggested in the articles above.

A*vacuum guage with a telltale needle can be very usefull.

You need not dispense with*your existing Racor, just add the crud capacity ahead of it.

Anyway just another suggestion.**


-- Edited by C lectric on Friday 19th of August 2011 05:19:53 PM
 
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