Water Fuel separating filter

[Ladiesinpinknightshirts]

Just got back from Walmart and saw an inline canister filter about the size of an oil filter. Looks like you can mount it on the transom. I guess it takes any water out of the fuel. I'm wondering what anyone else might have to say about these. I run a Brockway skiff with the usual 6 gallon gas can. If it's a good idea, I'll go for it but I don't like cluttering the boat if I don't need to.

Thanks, LIPNS

 

[JB]

Re: Water Fuel separating filter

You haven't told us anything about your engine.

A water seperating filter is really essential for an EFI or DFI engine and very good insurance for anything else.

 

[mthieme]

Re: Water Fuel separating filter

I have one on my skiff, but only because it was there when I got the boat. My old Mercs have two additional filters in the motor (not for water though). My feeling is with portable tanks it's too easy to keep water and contaminants out.
Having said that, a water seperater is also cheap insurance.
A fixed tank is more susceptible to condensation, or more appropriately not apt to be emptied out.
The ethanol will displace some water also.

 

[seahorse5]

Re: Water Fuel separating filter

Just got back from Walmart and saw an inline canister filter about the size of an oil filter. Looks like you can mount it on the transom. I guess it takes any water out of the fuel. I'm wondering what anyone else might have to say about these. I run a Brockway skiff with the usual 6 gallon gas can. If it's a good idea, I'll go for it but I don't like cluttering the boat if I don't need to.

Thanks, LIPNS

the following article is a few years old and it tells you all about filters.

http://continuouswave.com/whaler/reference/fuelFilter.pdf

 

[pvanv]

Re: Water Fuel separating filter

Considering that you are probably running E-10 fuel, if you can possibly accommodate the water-separating filter, please do it.

I service boats with onboard-mounted and portable tanks, as well as OB's with integral tanks. In NYS, where we have had that awful E-10 for a couple of years now, the water contamination issues have gone way up. Many new motors have been coming in for sputtering or no-start problems. 90% have been water contamination. Onboard tanks are the most prone to the condensation issues, as noted.

Last season, I poured a CUP of water out of a 6-gal tank that was less than a month old. This would have been caught by a water separator. None of the boats that run water-separating filters have had water-in-the-carb issue.

Of course, you do need to change the filter, at least annually. And, while they all capture water, some of the cartridges are better filters than others. We were selling the generic units, and switched to the Tohatsu/Nissan filters (we're a Tohatsu dealer), because the price was about the same, and the filters are much finer (say 10 microns), so, in addition to providing a settling bowl for the water, they also provide pretty clean fuel to the motor.

 

[dingbat]

Re: Water Fuel separating filter

Last season, I poured a CUP of water out of a 6-gal tank that was less than a month old. This would have been caught by a water separator. None of the boats that run water-separating filters have had water-in-the-carb issue.

Of course, you do need to change the filter, at least annually.

And here in lies the problem with 95% of the E-10 problems, lack of maintenance.

 

[Ladiesinpinknightshirts]

Re: Water Fuel separating filter

Thanks for the filter article link. In response to what engine I'm running, it's a two cylinder 30hp Johnson 1995 model. I still haven't decided what to do. I imagine the extra filtering (down to 10 microns) will help to keep the carb cleaner too.

 

[mthieme]

Re: Water Fuel separating filter

Considering that you are probably running E-10 fuel, if you can possibly accommodate the water-separating filter, please do it.

I service boats with onboard-mounted and portable tanks, as well as OB's with integral tanks. In NYS, where we have had that awful E-10 for a couple of years now, the water contamination issues have gone way up. Many new motors have been coming in for sputtering or no-start problems. 90% have been water contamination. Onboard tanks are the most prone to the condensation issues, as noted.

Last season, I poured a CUP of water out of a 6-gal tank that was less than a month old. This would have been caught by a water separator. None of the boats that run water-separating filters have had water-in-the-carb issue.

Huh ?

 

[gss036]

Re: Water Fuel separating filter

Personally, I run a Racor/Honda, but only because I have a 115 gal internal aluminum tank it is suspetable to condensation. If you just burn fuel from a 6 gal tank, might be a good idea about once a month to dump it in another tank and let it settle out, if there is water it will settle to the bottom, then you can put it back into the boat tank. You just can not leave gas in the can for months on end. Common sense.

 

[pvanv]

Re: Water Fuel separating filter

Huh ?

We have found that, even with the portable 6-gal tanks, if the vent is left open (some want to do that to keep the tanks from swelling up like a throw pillow in the sun -- even though I recommend it be closed and out of the sun), there can be a tremendous accumulation of water in a short amount of time.

What happens is that as the tank warms in the day and cools at night, air, with very high humidity, (since it is on the boat at lake level), is drawn in and expelled from the tank in a daily cycle. During cooling, moisture condenses in the tank. Also, the E-10 fuel, which really loves to absorb water, grabs the water right out of the air. If allowed to continue to the saturation point of the fuel mix, the E-10 fuel then phase separates as the water and alcohol drops out. The lower the fuel level (more air in the tank, and more air exchange) the worse this is.

FWIW, the resulting gas, floating above the water, is a significantly lower octane, since the alcohol (the addition of which raised the octane) drops out in the water mixture. So even after removing the water, the gas is lower octane.

Running a water-separating filter will catch the water, and, while the phase-separated gas that remains, and passes through the filter, isn't the best, it's a lot better than trying to run on water.

We have also found that running a good gas stabilizer, such as K100-MG helps the gas stay together, rather than separating.

 

[mthieme]

Re: Water Fuel separating filter

Never had that happen.
I thought MD was humid.
You guys must have gills up there.

 

[pvanv]

Re: Water Fuel separating filter

Interestingly, it doesn't happen to everyone here. Seems some are located -- or oriented in slips or moorings that are more succeptible to the problem than others. Never happened to me, and I don't use a lot of gas, so it's not unusual for me to have late-May-pumped fuel aboard on Labor Day. But then I keep the portable tanks out of the sun, with vents closed, and I religiously add K100-MG stabilizer before each fillup.

 

[dingbat]

Re: Water Fuel separating filter

Interestingly, it doesn't happen to everyone here. Seems some are located -- or oriented in slips or moorings that are more succeptible to the problem than others.

Chances are it?s not condensation, it's free water getting into the tank from leaving it open in the rain, etc.

Remember the equal and opposite reaction? People tend to forget, and the additive dealers don?t want you to know, that there is a constant cycle of condensation and evaporation going on at all times. What condensates will evaporate on the next cycle evaporate.

Try this one time. Pour a gallon of gasoline into an open container and leave it in the storage shed. Let it sit for a month or so and check to see how much water has collected in the bottom of the container. What you?ll find is that your container will have no water in the bottom and that you?ll have less gasoline than you started with. Quite different than what some would like you to believe.

 

[krakatoa]

Re: Water Fuel separating filter

What an interesting topic. I cuurently shipon out from my gas tank over a liter of water. I have NO IDEA where its come from in since Im sure that the gas tank is not broke cause there is no gas smell or leaks inside the boat. But have a lot or trouble regarding water in the gas tank, actually last Sat I had to take out all my carbs (4) and open it to take the water out. I install a Racor too. Hope this help me with this issue. I would like to hear from the PROS anytips or idea how the water win access to the gas tank and maintain the weater out. Its healthy to close the vents when the boat is stored?

Thanks

 

[pvanv]

Re: Water Fuel separating filter

That's a LOT of water. If it's an onboard tank, you may be getting rainwater through a poor fuel fill o-ring on deck. If it's a portable, and it's in the rain, same possibility. Yes, we usually recommend closing vents when not in use. Likewise, you will want to keep any plastic tanks out of the sun, especially if the vent is closed. Otherwise, it can swell up like a throw pillow in the sun.

A good stabilizer, such as K100-MG doesn't hurt, either.

 

[krakatoa]

Re: Water Fuel separating filter

Regarding the fuel tank is a "below deck tank" but maybe you`re right I will change thwe deck fill and the thru hull vent and lets see whats happen.

 

[pvanv]

Re: Water Fuel separating filter

I have also seen thru-hull vents allow water ingress when the boat is heeled, or low in the stern when idling. Happens frequently on sailboats. I would confirm that this isn't happening. You may want to get a vented loop in line, or possibly relocate the vent up higher if that's a possibility. Either way, seawater in the fuel isn't a good thing.