Reply
 
Thread Tools Display Modes
 
Old 07-07-2016, 02:20 PM   #21
Dauntless Award
 
Wxx3's Avatar
 
City: New York, NY
Country: USA
Vessel Name: Dauntless
Vessel Model: Kadey Krogen 42 - 148
Join Date: Jan 2013
Posts: 1,977
Quote:
Originally Posted by Bay Pelican View Post
We polish at least once a month and anytime we take on fuel. Usually I run it so that each tank is run through the filter four or five times. I can tell by the state of the fuel polishing filter and gunk that I drain from the filter housing that the polishing does some good. Better the water and gunk goes to the dump then to my engine.

Our polisher takes from the bottom of the tank and returns to the top of the tank so it gets the gunk and the water.


Maybe Krogen thing since we have such big tanks? But I do exactly as Marty above.

Sometimes, the fuel is obviously very clean, as well as the tank and I stop after a few hours after fueling.

Sometimes, it's dirtier, but as much as it could be the fuel, it's usually the tank and what sits in the bottom inch. What's best is to polish in rough seas, I have and it picks up a lot of stuff, BUT having two tanks, I always know which tank is "better" and in rough seas, I use the better tank.

Tomorrow, I will be adding a full fuel load, almost 700 gal, so I will polish each tank for a few hours over the weekend, but don't expect anything much. If there is more than that, I'll keep polishing until there isn't.

All in all, for my type of cruising, the $500 I spent on the FP system was worth it as it also gave me a way to transfer fuel.

If you don't have a system and you are using a few hundred gallons a year if that, don't find problems you don't have.
__________________
Advertisement

__________________
M/Y Dauntless, New York
a Kadey Krogen 42 Currently https://share.delorme.com/dauntless
Blog: https://dauntlessatsea.com
Find us: https://share.delorme.com/dauntless
Wxx3 is offline   Reply With Quote
Old 07-07-2016, 03:08 PM   #22
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 13,911
Quote:
Originally Posted by sunchaser View Post
IMHO most of our experiences are anecdotal. The smartest boat guy that has appeared on the Forum is RickB. He says keep the tank levels up during storage. Good enough for me, but maybe his mind has been changed with today's lower sulfur and maybe cleaner diesel.

RickB speak to us through a savant.
Funny you should say that.....

Once and awhile in different marina heads, between the graffiti and "Kilroy was here" cartoons, I see one of his advice tidbits written down.

I think I saw his ideas on tank fills in one outside of Savannah and I copied it down...here it is....

"My general rule is keep the tank levels high to reduce the volume of air exchange due to temperature variations.

If you live in an area where the temperature/dew point spread is low and you park the boat with warm fuel tanks, you will draw in atmospheric moisture as the ullage space cools and it will condense on the tank walls.

That moisture may lead to corrosion of tank surfaces and it will increase the amount of suspended or free water.
It does not mean the sky will fall or your fuel will become a bug ranch and destroy your engine.

Keeping tank levels high will not cure warts or foot odor or improve the quality of your bow ornaments but it will minimize the risk of adding moisture to the fuel if you live in certain climates and have a pattern of operating that promotes regular and substantial air exchange in the tank. " RickB.....
__________________

psneeld is offline   Reply With Quote
Old 07-07-2016, 03:20 PM   #23
Dauntless Award
 
Wxx3's Avatar
 
City: New York, NY
Country: USA
Vessel Name: Dauntless
Vessel Model: Kadey Krogen 42 - 148
Join Date: Jan 2013
Posts: 1,977
Quote:
Originally Posted by psneeld View Post
Funny you should say that.....

Once and awhile in different marina heads, between the graffiti and "Kilroy was here" cartoons, I see one of his advice tidbits written down.

I think I saw his ideas on tank fills in one outside of Savannah and I copied it down...here it is....

"My general rule is keep the tank levels high to reduce the volume of air exchange due to temperature variations.

If you live in an area where the temperature/dew point spread is low and you park the boat with warm fuel tanks, you will draw in atmospheric moisture as the ullage space cools and it will condense on the tank walls.

That moisture may lead to corrosion of tank surfaces and it will increase the amount of suspended or free water.
It does not mean the sky will fall or your fuel will become a bug ranch and destroy your engine.

Keeping tank levels high will not cure warts or foot odor or improve the quality of your bow ornaments but it will minimize the risk of adding moisture to the fuel if you live in certain climates and have a pattern of operating that promotes regular and substantial air exchange in the tank. " RickB.....


Thank you Rick B and Paul.
__________________
M/Y Dauntless, New York
a Kadey Krogen 42 Currently https://share.delorme.com/dauntless
Blog: https://dauntlessatsea.com
Find us: https://share.delorme.com/dauntless
Wxx3 is offline   Reply With Quote
Old 07-07-2016, 03:37 PM   #24
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 5,315
And to the OP, I do not know how much your Volvo D6's pump versus how much they burn but there is a good chance that your engines and your current filters are doing a good bit of polishing as it is.

My Cummins pump 3-4 times more than they use....so the fuel goes thru the filter circuit often.
__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B
Baker is offline   Reply With Quote
Old 07-07-2016, 04:05 PM   #25
Senior Member
 
City: Between Oregon and Alaska
Country: US
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 276
Fuel polishing is just the newest income enhancing product for those that make and sell the systems. I've been running and rebuilding diesels for almost 60 years. I also worked in a family business that specialized in getting mothballed ships and boats running again. Often sitting for decades.
If you have Racors or similar, you're polishing the fuel as you run. Finer primary filters are available for most housings. I run 2 micron in mine. My Detroit mains circulate about 75 gallons an hour, so the fuel goes thru the filters many times. I buy fuel from places that sell high volumes of fuel and change their filters. Not some marina that has a different kid running the fuel dock every week. I change the primaries by vacuum reading and the current ones were installed in 2011 and the pair have about 2500 hours or thousands of gallons pass thru. The tanks are 1942 steel. I do use a biocide a couple times a year. Never had a diesel fuel problem in my life. And the new low sulfur fuel, like most EPA mandates, is crap.
Lepke is offline   Reply With Quote
Old 07-07-2016, 05:56 PM   #26
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 13,911
Well, for us Lehman 120 owners, they return almost no fuel.

Literally drops per hour.

The engine and Racor really aren't polishing...

Many will argue unless you have significant fliw or agitation...most engines really don't do much in the way of cleaning up a bad tank, but may keep good fuel good.

One issue is climate...never had a problem up north, first sailboat in flirida, the tanks turned to black goo pretty quickly till I started using Biobor.
psneeld is offline   Reply With Quote
Old 07-07-2016, 06:17 PM   #27
Senior Member
 
Fletcher500's Avatar
 
City: San Diego
Country: USA
Vessel Name: Chelsea Rose
Vessel Model: Beneteau, 44, Volvo D6 Mains
Join Date: May 2016
Posts: 285
Burn rate on plane is about 213gph per engine. I have dual Racors, and watch the needle. They are high pressure, common rail, so yes, the amount of fuel flow is much greater than the amount delivered to the injectors, so I like your polishing analogy.

Quote:
Originally Posted by Baker View Post
And to the OP, I do not know how much your Volvo D6's pump versus how much they burn but there is a good chance that your engines and your current filters are doing a good bit of polishing as it is.

My Cummins pump 3-4 times more than they use....so the fuel goes thru the filter circuit often.
Fletcher500 is offline   Reply With Quote
Old 07-07-2016, 06:21 PM   #28
Senior Member
 
Fletcher500's Avatar
 
City: San Diego
Country: USA
Vessel Name: Chelsea Rose
Vessel Model: Beneteau, 44, Volvo D6 Mains
Join Date: May 2016
Posts: 285
This was my understanding as well. If I wake up in the morning and see water/dew all over the boat, then the same argument can be made for the inside of a tank.

But, as I stated earlier, this forum has folks on it with many miles under their keel, and no problems with semi full tanks so I can appreciate their comments.

Personally, I try to keep my tanks full, and will not rely on them to cure my bad lower back.

[QUOTE="My general rule is keep the tank levels high to reduce the volume of air exchange due to temperature variations.

If you live in an area where the temperature/dew point spread is low and you park the boat with warm fuel tanks, you will draw in atmospheric moisture as the ullage space cools and it will condense on the tank walls.

That moisture may lead to corrosion of tank surfaces and it will increase the amount of suspended or free water. [/QUOTE]
Fletcher500 is offline   Reply With Quote
Old 07-07-2016, 06:22 PM   #29
Senior Member
 
Fletcher500's Avatar
 
City: San Diego
Country: USA
Vessel Name: Chelsea Rose
Vessel Model: Beneteau, 44, Volvo D6 Mains
Join Date: May 2016
Posts: 285
Woops, that was my other boat that I saw in a magazine last week. This one burns 13 gph per engine.

Quote:
Originally Posted by Fletcher500 View Post
Burn rate on plane is about 213gph per engine. I have dual Racors, and watch the needle. They are high pressure, common rail, so yes, the amount of fuel flow is much greater than the amount delivered to the injectors, so I like your polishing analogy.
Fletcher500 is offline   Reply With Quote
Old 07-07-2016, 06:22 PM   #30
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 9,584
My builder recommended against installing a polishing system, and my boatyard dismantled it. Nevertheless, am using its pump and piping to transfer fuel among tanks and to prime engine as needed.
__________________
Kar-KEEN-ez Koot
markpierce is online now   Reply With Quote
Old 07-07-2016, 06:24 PM   #31
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 13,911
Does An Empty Tank Condensate? Photo Gallery by Compass Marine How To at pbase.com

It is not that sjmple.....
psneeld is offline   Reply With Quote
Old 07-07-2016, 07:03 PM   #32
Guru
 
BandB's Avatar
 
City: Fort Lauderdale
Country: USA
Join Date: Jan 2014
Posts: 9,938
Quote:
Originally Posted by Lepke View Post
Fuel polishing is just the newest income enhancing product for those that make and sell the systems. .
Actually fuel polishing isn't new nor is it a fad. Alfa Laval has been doing it a long time and large yachts that travel trans ocean will generally have their systems as will many large commercial boats. It's just a small part of what the company does today. Alfa Laval hardly would notice if they didn't have their fuel polishing equipment. Also, those who deliver fuel have done polishing for years, helping boaters and others who have had issues, such as inserting water hose in fuel line.

Many of the systems being sold as fuel polishing today for smaller boats are nothing more than elaborate filtering systems and don't have centrifuges. We have one of those magical sounds good but really does virtually nothing type systems that came on our latest boat.

Fuel polishing has it's place, but it's place is a very small portion of the overall market and not the majority of boat owners here. However, I wouldn't think of crossing the Atlantic or Pacific without a system.
BandB is offline   Reply With Quote
Old 07-07-2016, 07:47 PM   #33
Senior Member
 
Fletcher500's Avatar
 
City: San Diego
Country: USA
Vessel Name: Chelsea Rose
Vessel Model: Beneteau, 44, Volvo D6 Mains
Join Date: May 2016
Posts: 285
BandB is correct. When I was engineer on ships 30 years ago there were numerous Alpha Lavelle systems and we were constantly breaking into those things and cleaning them to keep them happy. A key part of the engine room.
Fletcher500 is offline   Reply With Quote
Old 07-07-2016, 10:17 PM   #34
Guru
 
JDCAVE's Avatar
 
City: Lions Bay, BC
Country: Canada
Vessel Name: Phoenix Hunter
Vessel Model: Kadey Krogen 42 (1985)
Join Date: Apr 2011
Posts: 1,374
Fuel polish, frequency?

Fill once a year. Fuel polish when we move fuel from tank to tank. New fuel goes into the aft tanks and is polished when it is moved to the front tanks. Fuel for the port tank is moved to the starboard tank to trim the boat. The engine draws and returns to the starboard tank.

If you polish and return to the same 100 gallon tank, the half life theory means you have only polished 50% of the tank when you have polished 100 gallons. If you repeat the process and move 100 gallons through the system again, you will have polished 75% of the fuel. So it is more efficient if you can move fuel from a full tank to an empty tank.

The PO put an expensive ESI system on the boat, as well as new fuel tanks. Personally, I think it's overkill, but I have it so I use it.

Jim
Sent from my iPad using Trawler Forum
JDCAVE is offline   Reply With Quote
Old 07-08-2016, 05:47 AM   #35
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 15,251
The hassle is oil floats on water.

So unless the fuel pickup is at the tank low point any water will need to be removed.

A tank bottom drain , a dedicated low point suction pipe , or of course the deck served sump which is best of all.

Fuel pickups are seldom at the tank low point so water collects and decades of polishing cant get it

Eventually the boat is shaken enough in boisterous conditions to mix the fuel and water where the filter can grab it, and the gunk pealing from the tank walls.

An underway switchable/changeable filter bank and a case of filters is a big help.
FF is offline   Reply With Quote
Old 07-08-2016, 07:56 AM   #36
Guru
 
City: gulf coast
Country: pinellas
Join Date: Jun 2014
Posts: 1,952
With engines that return fuel running on low tank levels makes the fuel circulate much faster through the filters than with full tanks.
bayview is offline   Reply With Quote
Old 07-08-2016, 07:21 PM   #37
Senior Member
 
City: Marathon
Country: Usa
Vessel Name: silver gift
Vessel Model: 45 jefferson
Join Date: Nov 2013
Posts: 180
Replaced both of my fuel tanks eight years ago. In January located a leak. Back to ft Lauderdale for repairs. Took tank out and had welder make repair. Could not area so it was cut out and a patch was made. Checked tank ,all was good ,put back in. Took cut out piece to fuel supplier and ask his opinion of the mess at bottom of tank. My tanks bottom is shaped to the hull with the inboard plate ,so at this area angled ,v-ed shapeand hold all trash that is in the tank. His opinion was the the fuel had degraded because I stored it for months as we don't cruise as often as we should. Suggested we use the boat,burn and circulate and clean the fuel,or store less and polish it every 6 months or so. Made a polishing system and have much less fuel 100 gallons ves350 in each tank. Both welder and fuel supplier said that over time the toxicity in the bottom of the tank will degrade the welds and aluminium if it finds a weak weld or section. Hope pics show this.
Attached Thumbnails
Click image for larger version

Name:	IMG_20160708_115248.jpg
Views:	38
Size:	150.6 KB
ID:	54051   Click image for larger version

Name:	IMG_20160708_115236.jpg
Views:	31
Size:	69.1 KB
ID:	54052   Click image for larger version

Name:	IMG_20160708_115156.jpg
Views:	37
Size:	199.2 KB
ID:	54053  
Deckape is offline   Reply With Quote
Old 07-08-2016, 11:07 PM   #38
Guru
 
BandB's Avatar
 
City: Fort Lauderdale
Country: USA
Join Date: Jan 2014
Posts: 9,938
Quote:
Originally Posted by Deckape View Post
His opinion was the the fuel had degraded because I stored it for months as we don't cruise as often as we should. Suggested we use the boat,burn and circulate and clean the fuel,or store less and polish it every 6 months or so. Made a polishing system and have much less fuel 100 gallons ves350 in each tank. Both welder and fuel supplier said that over time the toxicity in the bottom of the tank will degrade the welds and aluminium if it finds a weak weld or section. Hope pics show this.
Yes, you are talking a different issue than water in the tanks. You're talking the fuel losing some of it's lubricity and other characteristics. That isn't going to happen in a short period of time but if fuel isn't turned over for a couple of years, it can become an issue. It's not a matter of clean or empty tank. With fuel and engines from decades ago, this wasn't the same issue it is today.
BandB is offline   Reply With Quote
Old 07-09-2016, 08:13 AM   #39
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 15,251
"Both welder and fuel supplier said that over time the toxicity in the bottom of the tank will degrade the welds and aluminium if it finds a weak weld or section."

This is why a real marine fuel tank has a sump ,

Only a boat assembler would call a box of fuel a fuel tank.
FF is offline   Reply With Quote
Old 07-09-2016, 09:46 AM   #40
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 5,764
DA

Possibly it was incompatible rod with the plate when in the presence of organic or water. Or non rated plate? Or yada yada -----

What do I know, I'm only a metallurgical engineer.
__________________

sunchaser is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 12:06 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012