Is Fuel Polishing Snake Oil?

[Maine Sail]

Maybe MaineSail can run some tests for us to help us decide the best approach.

Already have... My tank is drained for the winter.... Don Casey also said to let your sealant cure to form a gasket then tighten a second time and gave no advice on creating a countersunk bevel when bedding deck hardware. We now have THOUSANDS upon THOUSANDS of boats with wet decks....

I have never had a drop of water in my tanks since draining them in the winter and crap can't grow in what is not there......

 

[Steve Dion]

I would guess that most tanks get water in them from the lack of maintenance for the fuel filler cap. The o-rings get old and cracked and do not get changed before there is water seepage.

We keep a couple of these on board and try to change them every two to three years. Cheap maintenance.

 

[Maine Sail]

We keep a couple of these on board and try to change them every two to three years. Cheap maintenance.

I've changed ours twice since this April...... Once I knew the o-ring size I ordered 100 from a local wholesaler. Cost me $8.40. Cheap, easy and it takes about 4 seconds to change one... I keep a bunch on-board at all times.

 

[s sauer]

Having cleaned out my polyethylene diesel fuel tank and installed a 6 " diameter Seabuilt access plate for less than $150 and 1-1/2hrs time, I'd suggest installing an access panel & replacing all hoses and filters rather than 'fuel polishing'.
Once the tank was drained down thru normal use and the last two gallons of fuel pumped out and disposed, I cut the access hole with a jig saw and wiped it out completely with alcohol soaked rags. Interestingly there was a sooty deposit on the underside of the top of the tank and significant gunk around the fuel level sending unit that i doubt would have been removed by fuel polishing thru the existing fill line and fuel lines. Moreover, the tank can now be inspected and cleaned completely thru that access plate.

 

[heritage]

Already have... My tank is drained for the winter.... Don Casey also said to let your sealant cure to form a gasket then tighten a second time and gave no advice on creating a countersunk bevel when bedding deck hardware. We now have THOUSANDS upon THOUSANDS of boats with wet decks....

I have never had a drop of water in my tanks since draining them in the winter and crap can't grow in what is not there......

I agree that draining the tank is the best solution to preventing water in the tank. Because any condensation that goes to the bottom will later evaporate when temperature and humidity conditions change. But with a layer of diesel fuel in the tank, evaporation of water below the fuel is prevented.

Here is a document from GE concerning fuel tank condensation prevention:
http://www.gewater.com/pdf/Fact Sheets_Cust/Americas/English/FS1677EN.pdf

 

[Maine Sail]

I agree that draining the tank is the best solution to preventing water in the tank. Because any condensation that goes to the bottom will later evaporate when temperature and humidity conditions change. But with a layer of diesel fuel in the tank, evaporation of water below the fuel is prevented.

Here is a document from GE concerning fuel tank condensation prevention:
http://www.gewater.com/pdf/Fact Sheets_Cust/Americas/English/FS1677EN.pdf

When the tank is empty there is no condensation nor fuel to grow things in. I drain it off and put it into my homes oil tank.

Try this, stick a metal gas can in an enclosed outdoor structure with the cap off. Let it sit there for an entire year through similar temp swings a boat would go through over the winter. You will find after a full year that there is zero water in the tank...

That GE article was for large storage tanks that can't be left empty in an off season...

Most still believe in filling the tank, and that is fine, I just don't do that on my own boat...

 

[weinie]

Leaving the tank dry makes sense, but for those who can't go through the trouble of draining leftover gallons from the fuel tank each year and somehow dispose of it properly, is it better to leave the remaining fuel in the tank or to top it off?

 

[Stu Jackson]

...but for those who can't go through the trouble of draining leftover gallons from the fuel tank each year and somehow dispose of it properly, is it better to leave the remaining fuel in the tank or to top it off?

weinie, based on Maine Sail's last post, right before yours, is the answer. Either/or.

Your boat, your choice. Both will work.

 

[Dan Johnson]

RichH is absolutely correct!

A few years ago I had a fuel starvation problem, and had to replace several filters close together. I read up on RichH's postings, and concluded that the only way to solve the problem was as he stated--CLEAN THE TANK.

First I had to get the fuel out of the tank, so I went to Tractor Supply and built a fuel polisher from available pump and filter assemblies. It sucks at 15 GPM at the full diameter of the hosing, but I used a 1/2" OD PVC tube to reach down into the tank bottom, so was filling a 5 gal. jerry jug in about 5 min. The tube happened to reach the very bottom low point in a corner of the tank, completely emptying it.

When the tank was emptied, I used a saber saw to cut a hole in the tank to gain access. With clean rags, I wiped out every bit of residue I could, then installed a Sea-Built access port to close the tank. The vacuum gage has barely moved since, indicating that the fuel is staying relatively clean (using bio-cide eacj time I put a jerry can's 4 gal. in through a Baja filter).

See pix:

 

[RichH]

Leaving the tank dry makes sense, but for those who can't go through the trouble of draining leftover gallons from the fuel tank each year and somehow dispose of it properly, is it better to leave the remaining fuel in the tank or to top it off?

Weinie --- its like wearing soiled underwear.
Clean it up immediately when you find it, or ignore it and have a much much worse mess to clean up later on.
If you read the previous posts .... dont top it off, REMOVE it.

 

[capta]

Again old sea dogs are learning new tricks (ouch, learning hurts SO much at this age; anyway, I thought I knew it ALL!).
Thanks again RichH. All my life I've been filling tanks to store but this all makes sense.
So draining and/or cutting an access hole in a baffle-less 30 gallon tank is fairly easy.
What about my 170 gallon aloy tank most of which is inaccessible under flooring, framing and the table?
And I know it is filthy. I've even had a Racor 500 completely fouled BEFORE the element. I increased the fuel line size and added a ob tank bulb type pump inline.
We live aboard and run the generator 4 hours daily (most of our fuel use) and change filters quite often (ME & Gen).
Other than a new tank, have you any advice how to remove the sediment from the tank bottom (2 baffles) without access? Chemicals?
I do have 64 ounces of Star Tron Fuel Tank Cleaner aboard, but as we liveaboard and need to be able to rely on the engine at a moment's notice, I have hesitated to use it fearing it might plug the Racor at the wrong moment.
Thanks

 

[RichH]

The problem with tank cleaners and without visualizing whats happening inside ... you have no idea of the efficacy of cleaning ... and more importantly has the cleaner penetrated between the crud and walls and only loosened a huge slug of crapola which is now ready to break loose and cause a massive 'particle storm'?
170 gallons is a whopper and even with proper access ports is probably deeper than what a human arm can reach.
.

 

[Anonymous 121765]

Sail,

Mark's post really nailed it. Sometimes it's easy to over think on questions/problems you have to do.

I had fuel/engine problems in the past with my engine stalling at the worst possible times/conditions.

I did what Mark did & upon inspection, found 1/4" thick grey sludge covering in the bottom. I have an industrial piping background and after seeing the sludge, thought it was best to hand clean it.

For a polishing system to work in my opinion, you would need a good amount of pressure/spray. The "flush" side should have the ability of moving around while spraying something like the snakes used in pools. If you let the pool snake run long enough, the bottom & sides will eventually be cleaned in the randomness of the whipping flush hose.

However, how long will your tank polisher have to run until it does the job, and what will that price be? Not doing a visual inspection after polishing, how do you REALLY know if all the sludge is gone?

I (& Mark) decided to make our tanks easy to inspect & clean. We now are 100% sure of our tank condition. Why pay to guess.

My pal down here in Florida has a polishing business. His unique equipment uses $1.00 ea. flat sheet filters (not canister types) which allows him to charge better rates. Boat friends of mine have used him & were happy with the results, but I trust my eyes more.

CR