Black Sludge - SailNet Community
 2Likes
  • 1 Post By mbianka
  • 1 Post By krisscross
 
LinkBack Thread Tools
post #1 of 7 Old 06-10-2019 Thread Starter
Member
 
Join Date: May 2016
Location: Riverside, RI
Posts: 49
Thanks: 5
Thanked 1 Time in 1 Post
Rep Power: 0
 
Black Sludge

I just changed the fuel filters in my Yanmar 2GM20F. The Raycor filter had a slight layer of black gook in the bottom of the plastic bowl screwed on the bottom. Nothing appears to be floating in the fuel itself. And the secondary filter looked clean in the bowl. It's been just over a year since the last time I changed the filter. Am I looking at a bad fuel tank?? Is there a such thing as cleaning a fuel tank? The motor works perfect and always starts and runs so pretty sure it's not made it into the injectors.
As always any suggestions greatly appreciated.
wind cree is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 06-10-2019
Master Mariner
 
capta's Avatar
 
Join Date: Jun 2011
Location: somewhere south of civilization
Posts: 7,050
Thanks: 135
Thanked 370 Times in 358 Posts
Rep Power: 9
 
Re: Black Sludge

Depending on its size and access to the interior, cleaning a fuel tank can be an expensive worthwhile or worthless experience. Most tanks have baffles which limit the amount of cleaning that can be accomplished without making holes in the tank to clean behind the baffles.
We have dirty fuel tanks (38 years old) and we keep lots of filters aboard and change them frequently. If you don't already have a Racor 500 as your primary, chuck what you have and install one of those with or without the gauge.
Then just change the filter frequently and you'll not have to worry. The nice thing about the Racor is that you change the filter from the top, so you don't have to make a mess of your bilge.
Many will try and suggest a fuel polishing system, but your diesel does that anyway so unless you are starting out with a perfectly clean tank, they aren't really going to make a whole lot of difference. Fuel polishing doesn't clean what's growing on the sides and top of the tank. A fuel polishing only cleans out whatever is suspended in the fuel, just as the return system on your engine does.

"Any idiot can make a boat go; it takes a sailor to stop one." Spike Africa aboard the schooner Wanderer in Sausalito, Ca. 1964.
“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats.” ― Kenneth Grahame, The Wind in the Willows

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

facebook.com/svskippingstone
capta is online now  
post #3 of 7 Old 06-10-2019
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 19,514
Thanks: 82
Thanked 550 Times in 527 Posts
Rep Power: 11
   
Re: Black Sludge

If you have black sludge in the bottom of the primary, it's most likely dead bacteria that live in diesel. Especially, if there is high moisture or water in the diesel.

I used USA Fuel Service to clean my tanks. Not sure where you are or if they have anyone close. It would appear you do need to clean your tanks. They pump out all the old fuel first, then polish it to remove impurities. Then they spray solvents into you tank through whatever access they can find. They used the fuel level sender in my case. They pump out the solvents and debris, then put the polished fuel back.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
 
post #4 of 7 Old 06-11-2019
Member
 
Join Date: Mar 2016
Location: Sydney Australia
Posts: 42
Thanks: 2
Thanked 3 Times in 3 Posts
Rep Power: 0
 
Re: Black Sludge

Quote:
Originally Posted by Minnewaska View Post
If you have black sludge in the bottom of the primary, it's most likely dead bacteria that live in diesel. Especially, if there is high moisture or water in the diesel.

I used USA Fuel Service to clean my tanks. Not sure where you are or if they have anyone close. It would appear you do need to clean your tanks. They pump out all the old fuel first, then polish it to remove impurities. Then they spray solvents into you tank through whatever access they can find. They used the fuel level sender in my case. They pump out the solvents and debris, then put the polished fuel back.
Hi i have found that the black "sludge" can sometimes be asphaltenes that appear as a sludge however when closely examined they appear as little black balls that clog the fuel system. If you can get some of the black sludge out into a small container, place some in the palm of your hand and add some metho and rub, if it dissolves into a blackish brown paste you have asphaltenes. Polishing the fuel through a 30 micron filter worked for me.

Cheers, Uncle Bob the 1st from Sydney Aust.
Uncle Bob the 1st is offline  
post #5 of 7 Old 06-11-2019
Senior Member
 
Join Date: Sep 2014
Location: Northeast U.S
Posts: 1,935
Thanks: 5
Thanked 74 Times in 71 Posts
Rep Power: 5
 
Re: Black Sludge

Quote:
Originally Posted by wind cree View Post
I just changed the fuel filters in my Yanmar 2GM20F. The Raycor filter had a slight layer of black gook in the bottom of the plastic bowl screwed on the bottom. Nothing appears to be floating in the fuel itself. And the secondary filter looked clean in the bowl. It's been just over a year since the last time I changed the filter. Am I looking at a bad fuel tank?? Is there a such thing as cleaning a fuel tank? The motor works perfect and always starts and runs so pretty sure it's not made it into the injectors.
As always any suggestions greatly appreciated.
When I converted my boat from diesel to Electric propulsion I decided to use the old diesel fuel tank as a fresh water wash-down tank. I was amazed at what I discovered when I began to clean out the old diesel tank. You can see what I found at and how I cleaned out the tank at this blog post:
https://biankablog.blogspot.com/2011...-of-grime.html
MarkofSeaLife likes this.

Mike
Currently: Enjoying Summer's sailing season

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mbianka is online now  
post #6 of 7 Old 06-11-2019
Senior Member
 
krisscross's Avatar
 
Join Date: Feb 2013
Location: North Carolina
Posts: 4,107
Thanks: 40
Thanked 223 Times in 222 Posts
Rep Power: 7
 
Re: Black Sludge

Had my tank professionally cleaned out before I left for the trip from Pensacola Florida to North Carolina. They pulled over 3 gallons of water out of about 30 gallons of fuel, as well as some black solids that are bacterial in nature. Well worth it in my opinion.
MarkofSeaLife likes this.

Be kind, for everyone you meet is fighting a hard battle.
Plato
krisscross is online now  
post #7 of 7 Old 06-11-2019
Moderator
 
MarkofSeaLife's Avatar
 
Join Date: Nov 2010
Location: London!
Posts: 6,178
Thanks: 62
Thanked 285 Times in 258 Posts
Rep Power: 10
 
Dock
Re: Black Sludge

When I had a fuel problem I had a mate come over and he happened to have a fuel transfer kit and a polisher. So we sucked out all the fuel & whacked in ferry cans and polished it.

We then squirted a ferry of clean diesel around the inside of the tank and sucked it out again.

Nice clean tank. Not pristine, but clean enough.

Pretty easy to do with the fuel transfer pump and polisher.

Sea Life
Notes on a Circumnavigation:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


People can say they want freedom, but offer them the keys to what chains them, a map to where they want to go,
And they'll turn it down for the cell they know
MarkofSeaLife is offline  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome