Portable fuel polishing units

[chuck53]

A few weeks ago, there was a service guy at our marina with a portable fuel polishing unit that he brings to your boat to polish the fuel.
I didn't get a chance to talk to the guy but I would like to have it done to my boat.

Has anyone had any experience with this kind of service? Good, bad, depends on the service guy?

Approximate cost for a 25 gallon tank?

[newportermike]

I had this done to a boat I just bought that had been sitting in the yard for 2 yrs. I had to sail it from Boston to Newport so did not want to take a chance with the fuel. I had only about 14 gallons in the tank and got estimates around $500, but shopped around and got it done for $275. Now that seems like a lot but they cleaned all the gunk from the bottom of the tank also. If you just have the fuel pumped out there is a good chance that the algae and gunk at the bottom of the tank will screw up your day when you hit rough water and things get sloshed around. I would reccomend it. I have had no problems and we ended up motoring a lot.

[Stumble]

Getting a tank cleaned 'just because' is probably not worth it. You will wind up paying for something you likely don't need. On the other hand if you do need it, it can save a fortune in bloody knuckles, and filters.

The best way to check is just to open the inspection port on your fuel tank, and take a look around. If there is crud, or suspended solids its defiantly worth the money. If the tank is bright and shinny, there's no reason to worry about it.

I have had it done a number of times, and it's a pretty easy process. The portable polisher is just a high volume pump with a series of step down fuel filters. It just recirculates the fuel in your tank for a while until the entire tank has been cycled a few times. Ideally you use the return hose to agitate the tank a little to try and get the gunk off the bottom (same reason it's a high volume pump).

[Flybyknight]

$250 bucks is a lot of money to me. What I did was pull the tank.
Drained most of it but left about a gallon.
It had baffles so I got about 5 lbs. of small chain, stuck it in the tank and swished.
I was amazed at what came out.
Repeated several times with clean fuel, until everything came out clean.
Happen to have a very large funnel, so using kitchen paper towels as a filter I was able to recover most of the fuel which appeared very clear, but decided to put it in my truck instead.
I installed a Racor and have not had any fuel issues.

Dick

[aeventyr60]

I had it done on a 90 gallon tank that was not removable. They cut an inspection port in as well. The tank was scrubbed clean and about a half gallon of black goo was removed. The tank was 23 years old. I had lots of problems with clogging filters (even with dual racors) before the tank was cleaned. After no problems.....If you have inspection ports, try draining the tank and cleaning it out on your own. I don't think just filtering the fuel is enough, the tank needs to be physically scrubbed, rubbed and wiped out.

[pdqaltair]

Originally Posted by newportermike

I had this done to a boat I just bought that had been sitting in the yard for 2 yrs. I had to sail it from Boston to Newport so did not want to take a chance with the fuel. I had only about 14 gallons in the tank and got estimates around $500, but shopped around and got it done for $275. Now that seems like a lot but they cleaned all the gunk from the bottom of the tank also. If you just have the fuel pumped out there is a good chance that the algae and gunk at the bottom of the tank will screw up your day when you hit rough water and things get sloshed around. I would reccomend it. I have had no problems and we ended up motoring a lot.

How are you cerain the tank bottom was cleaned? You wouldn't be able to see it, not really. Or is that the answer? On larger tanks you certainly could not, certainly not if using dyed diesel.

(I don't mean to be the kid we all hated, saying "how do you know?" to every statment as an empty and annoying challenge. I'm honestly curious.)

[Flybyknight]

Originally Posted by aeventyr60

I had it done on a 90 gallon tank that was not removable. They cut an inspection port in as well. The tank was scrubbed clean and about a half gallon of black goo was removed. The tank was 23 years old. I had lots of problems with clogging filters (even with dual racors) before the tank was cleaned. After no problems.....If you have inspection ports, try draining the tank and cleaning it out on your own. I don't think just filtering the fuel is enough, the tank needs to be physically scrubbed, rubbed and wiped out.

Right on!

Dick

[chuck53]

Guys, thanks for the comments.

[RichH]

As an engineer deeply involved in filtration engineering for over 35 years .... recirculation polishing of fuel without a thorough mechanical cleaning of the tank is of very little benefit.

Simple speak: If you dont get inside the oil tank and scrub the thick biological deposits from the walls, these 'agglomerated' bio-particles will continue to break off the walls and re-contaminate the oil, plus the cellular debris that does break loose only becomes the nucleation sites for even more growth of larger particles. Without a thorough cleaning of the tank walls, recirculation polishing of the fuel oil is only a very temporary remedy.

Most tank fouling is usually caused by a fungus - Cladosporium Resinae or 'kerosene fungus', etc., species that use the carbon content of oil as their nutrient source. It usually enter the tank through the VENT. Growth of such species is exponential.
How to know when to clean out a tank: remove some of the tank oil, put it into a clear glass container and hold it up between your eyeballs and a strong white light - if there is any 'haze' noted when you look through the oil to the strong white light, it means that the oil is fouled/contaminated and that the tank should be cleaned .... then the fuel should be 'polished'.
For the price of a single commercial 'polishing' one can easily build their own on-board polisher: a simple Walbro type 12 vdc transfer pump, a 10" steel filter housing, a ~15µM 10" X 2.5" dia. industrial resin bonded cellulosic filter .... just continually pump directly from the bottom of tank directly back to the tank. A good 'rate' for recirculation polisher is approx. 2-3 gallons per MINUTE per 100 gallon tank. If the system is 'clean' that 15uM filter operated anytime the engine is on will produce a particulate level at 'submicronic' levels, the oil will be 'crystal clear' (no haze) .... and there will be no challenge to the system's inline (Racor) filters. Any particles that do get into the tank will be constantly and quickly removed. Such a system is very cheap to use as you wont be changing out your racors all that often as the debris is removed by the 'cheapy' industrial filters in the recirc. loop.
Do NOT put an onboard recirculation polisher in/on the main fuel delivery system or its return line.

;-)

[Captainmeme]

My tank does not have an inspection port. Can the biological deposits be washed off the walls using the transfer pump as a pressure washer?