Removing emulsified water

[P69]

It seems pretty dead around here, so I'll throw this one out. I guess I'm the only MF'er who decided to do a refit this year and everyone's out sailing.

Well anway, what is the best filter to remove emulsified water from diesel fuel?

Is there a filter that will remove all water, both free and emulsified?  I've read the fuel polishing threads and very few address the emulsified water issue.  I've seen a lot of discussion on filtering/polishing, but nothing specific to removing emulsified water, it seems like no one wants to talk about emulsified water or it's just not a big deal or there is no solution.

So far, all I've been able to find is that Fleetguard filters can remove emulsified water (95% removal) and I found one company stating 100% filteration of free and emulsified water (Combust Filters, combustionusa.com).  Has anyone actually tested a filter to see if it removed the emulsified water?

Today, I filtered 30 gallons (six 5 gallon jugs) of three year old old diesel and found that the racor captured the particulates, but it looks like 1) most tanks had emulsified water or 2) the racor emulsified the water that was in those tanks. Based on what I saw, I starting to think that maybe racors aren't what they're cracked up to be. I used a reverso 3gpm pump sucking fuel through a racor 500.

The result was only one 5 gallon tank has clear fuel. The other five have cloudy fuel (some more than others). I filtered each jug three times with a 30 micron filter, then once with at 10 micron filter.  At the end of each pass I left about a cup in each tank, then swished and dumped. Each time, I saw fewer and fewer particulates.

But it's all cloudy.  Maybe there is more than water making it cloudy.  Keep in mind that I am assuming that the cloudiness is emulsified water I have not tested to confirm. The fuel was  three year old fuel from the boat's filthy tank that I removed last December and stored on shore in six 5 gallon plastic jugs. I now have a new fuel tank (old one had millions of pinholes ) and I'm probably going to trash those 30 gallons and start with clean fuel in the new tank, but I still have the question of which filter will remove emulsified water from the diesel fuel because I still want to put that filter on my polishing system.

So, if any one has experience removing emulsified water, let's hear'em.


The other question I have is what affect do valvtec BioGard  and PriD (or all the other bicides/stabilizers) have on promoting water/fuel emulsification, but maybe that should be a different thread.

[Jim S]

As far as I know, Racor is still the standard for fuel filtration.  This is for the process of delivering fuel to the engine and polishing a contaminated tank.  Racor has a 2 micron filter but I don't know whether that will get your cloudyness out.

For the process of straining fuel from outside tanks to the fuel tank I have used a Baja filter successfully.  It appears that the Baja is no longer available but most chandleries have a funnel fuel filter that will filter out the water.  If the fuel is full of all kinds of sludgy mess, a cotton rag, t-shirt type of cloth, pre-filter over the top of the screen filter will catch the sludge and keep it off of the screen. 

I have found that the best rule is prevention of contamination in the fuel.  I always filter every drop of fuel through my Baja and I use an antimicrobial, Biobor, as well.  In ten years the fuel in the tank has stayed free of mess in the bottom of the tank.

Hope this helps

JimS