Quick, simple fuel polisher

Nov 18, 2010
2,441
Catalina 310 Hingham, MA
We have been struggling with fuel issues since getting bad fuel running from Irma and Maria in 2017. The biggest problem is that Catalina did not install any inspection ports in the the fuel tank. To effectively clean the tank you need to access both sides of the baffle. Because the tank is installed under the sugar scoop you need to remove the tank to install clean outs. And why remove a 20 year old metal tank and re-install it, it might be better to get a new tank. That's a job better suited to when we are stopped to work again. So I'm stuck trying to figure out the best way to keep the motor going for the next year or two.

I have decided my best option is install a fuel polishing system I can use regularly. Especially under sail in rough conditions when stuff get stirred up.

Some of these modifications would be slightly different on a stock motor with the Facet lift pump and Racor R20 primary filter. But the concept would still work.

We have a Racor 500 as our primary fuel filter and a Walbro FRB-8 fuel pump mounted on the bulkhead. We run a 10 micron filter element in the Racor 500. The on engine fuel filter is a 2 micron. The Walbro isn't cheap but I had gotten frustrated with the poor quality of the cheap $35 automotive lift pumps. Since I was going to spend some real money on the fuel lift pump I researched options. The Walbro is larger than the factory Facet cube style pump. But it is also rebuildable in the field. A new Facet would have cost $80, the Walpro was $150. The Facet delivers fuel at about 7 gph, the Walbro varies on demand up to 40 gph. I did have the idea of building a polisher in mind when I made the decision to go with the Walbro.

To make the polisher I installed a three-way valve on the effluent of the Walbro pump. One direction goes to the supply for the on engine filter. The other direction is hard plumbed to a T fitting. One side of the T fitting goes to the return line to the tank. The other side of the T fitting goes to return coming from the engine.

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When the three-way valve is turned to the engine fuel goes from the pump, to the one engine filter and then on to the high pressure pump and injectors. The return fuel goes to the T fitting and then on to the return line to the tank. When I select the polish position, the fuel goes from the pump directly to the return line to the tank.

The factory power setup for the pump is a quick disconnect tied to the solenoid switch. This is why you can push the key forward to activate the fuel pump as part of the self-priming system. On the pump side of the quick connect I added a second wire going to a switch. The other side of the switch is connected to my positive buss in the battery compartment with a fuse in line. If you turn on the switch, the fuel pump is activated. This is great for priming filters after changes. But it does active the solenoid switch and therefore activates the preheat circuit, you wouldn't want to leave this on for long polishing efforts. But disconnecting the quick connect eliminates the preheat circuit. You could also add a second switch to shut off the preheat circuit. I did take a unused heat shrink quick disconnect end, put some wire insulation in the crimp end, crimped and shrunk it. Now it works as a cap to eliminate accidentally groundings to the engine.

So to activate the polisher you turn the selector valve to polish, disconnect the quick connect and flip the switch. It can run for hours polishing the fuel and returning it to the tank. Not a perfect system but good.

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The next step will be to add a 2 micron filter somewhere on the return line, likely with a bypass loop so that returned fuel from the engine isn't going through it.

Before I started building the system I shocked the tank with a double treatment of Biobor JF fuel treatment. I then ran the polisher for 20 hours in three sessions. The fuel looked clean and there was some definite build up in the bowl of the filter. I then switched to a 2 micron filter and ran it for another 8 hours (not advised for the Facet pump). Following that I did another treatment of the Biobor JF and a treatment of Starbrite Diesel Watersorb. I have now been running the polisher again for 2 hours. The fuel is now cloudy. Hopefully this clears up after several hours of polishing.

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After the fuel clears up, I will change the filter back to a 10 micron and drain the sediment out of the bowl. Then it will be time to go for a sail in hopefully 6-8 foot seas to run the polisher while getting knocked around a bit.

I also need to break out the label maker and clean this up a bit.

Hopefully this works
 
Dec 25, 2008
1,580
catalina 310 Elk River
Every year I pump the tank dry with a drill pump connect before the Racor.
The old fuel goes in my house oil burner. Fresh fuel from a active truck stop, no additives, never a problem.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Every year I pump the tank dry with a drill pump connect before the Racor.
The old fuel goes in my house oil burner. Fresh fuel from a active truck stop, no additives, never a problem.
Never had a problem in the US. We got bad fuel from a marina in St. Thomas. They don't believe in holding back a percentage of the tank so they don't pump the sluge at the bottom. We were running from the hurricanes in 2017 and in a rush. Normally I fill Gerry cans, let them settle for a couple of days before decanting leaving the bottom few inches using a haha filter. Instead I pumped through the Baja filter only. We ended up going through 6 filters in a 8 hour motor.

I have pumped the tank dry several times and cleaned through the sender opening. But you can't really get in to clean that way. And you can't get to the other side of the baffle.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Jesse, nice work. Thanks for that.

What did you use on the threads for the new fittings? A friend (our sbo friend "Hello Below") loaned me some Jet Lube Petro Tape PTFE, good for petroleum oils.
 
Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
Was curious if you filter everything going into your fuel tank with a handheld filter? Seems like that is a precaution that I am going to continue doing all the time.
 

Clydo

.
May 28, 2013
338
Catalina C310 SF Bay/Delta
Was curious if you filter everything going into your fuel tank with a handheld filter? Seems like that is a precaution that I am going to continue doing all the time.
I too have used hand held filter ( removes dirt and water) - West Marine - and after returning small remaining portion in filter to container am amazed at junk left in my
five gallon container. Get diesel at busy truck stop so should be fairly fresh.

Clyde Thorington
C310 # 245
I LEAN TOO
San Jose, CA
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
JK like the polishing system. The additives help to clean the fuel and kill the activity of the fuel bugs.

I bought a boat with 120 gallons in 2 tanks of unknown age. First cruise the gunk filled the old Fram truck filter stopping fuel flow shutdown of the engine. Sailed home.

Replaced with a Racor 500M and between additives and 30micron filters I used up the fuel over a couple of years cruising, pumping the port tank fuel into the Starboard tank, cleaned the tanks back in business.

Your fuel polishing is a solid idea.

Helps to select your fuel supplier from a busy station that sells fuel to commercial users.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I had fuel problem for the first time after 12 years and so emptied all the fuel through a Racor filter into jerry
Jugs and used a shop vac to clean out tank and used a snake camera to look at sludge left in empty tank.
After using shop vac my tank was very clean and been very good back to running real good again.
Nick
 
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Oct 29, 2016
1,915
Hunter 41 DS Port Huron
Looks like you put some careful thought into this, just a question but instead of the valve and quick connect, could you not just have a complete stand alone polishing pump, filter and return line. Separate from the engine fuel delivery at least that way you could run anytime without any special adjustments.
Question #2, with the pump able to easily deliver fuel to a running engine could you not just split the line (1) side to the engine the other to the polishing line? couple of balancing valves would seem to make the polishing side run anytime the engine was running, you could then add a switch to run at will.
Just a couple of thoughts.......
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Looks like you put some careful thought into this, just a question but instead of the valve and quick connect, could you not just have a complete stand alone polishing pump, filter and return line. Separate from the engine fuel delivery at least that way you could run anytime without any special adjustments.
You would need separate pickup and return for this to be truly independent. When I eventually get a new tank I will likely have these installed. The other aspect is space. It doesn't seem like much, but right now I can't find room to add the 2 micron filter in a separate, small housing, never mind another lift pump, hoses, etc. Cruising a 31 foot boat takes compromises.

Question #2, with the pump able to easily deliver fuel to a running engine could you not just split the line (1) side to the engine the other to the polishing line? couple of balancing valves would seem to make the polishing side run anytime the engine was running, you could then add a switch to run at will.
Just a couple of thoughts.......
I think this would likely introduce air and other problems into the mix. I would not want to risk taking supply away from the running engine to polish.

Thanks for the suggestions
 

Tom J

.
Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Nice, compact system, Jesse. Years ago, I assembled most of the parts I would need to build a separate polishing system, but couldn't figure out where to install everything. My Racor was installed by Catalina under the aft bunk, so I hoped to mount the new parts there, but the bilge is too shallow.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Nice, compact system, Jesse. Years ago, I assembled most of the parts I would need to build a separate polishing system, but couldn't figure out where to install everything. My Racor was installed by Catalina under the aft bunk, so I hoped to mount the new parts there, but the bilge is too shallow.
I know, that bilge is like 1 inch too shallow for the filters. I have a Racor R20 housing. I want to make that a 2 micron filter in the polishing loop but can't find anywhere to mount it.

When we eventually remove this tank I will likely replace it with a plastic tank. I will have that configured with two inspection ports and a second set of pickup and returns for a dedicated polisher system. Then I could mount all the components of the polisher somewhere in the stern.
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Good morning JK. Installing a polishing system is a great idea. Especially if you only have access to poor quality fuel in out of the way locations or have large tanks for distance under power and likely the fuel will sit in the tank (during which it can grow bugs) for extended periods till it is needed.

But you may want to consider that polishing is designed to be removing the big chunks.
Racor identifies the issue “the 2-micron filter will clog quickly when there is contamination” in their discussion of which filter is “Best”.
This link may help you shape your plan.

Hope it helps.
 
Nov 22, 2011
1,192
Ericson 26-2 San Pedro, CA
Good morning JK. Installing a polishing system is a great idea. Especially if you only have access to poor quality fuel in out of the way locations or have large tanks for distance under power and likely the fuel will sit in the tank (during which it can grow bugs) for extended periods till it is needed.

But you may want to consider that polishing is designed to be removing the big chunks.
Racor identifies the issue “the 2-micron filter will clog quickly when there is contamination” in their discussion of which filter is “Best”.
This link may help you shape your plan.

Hope it helps.
Plus, the 2 micron is not nice to your fuel pump.
 
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rukidn

.
Apr 23, 2012
160
Catalina 310 258 Sandusky, OH
Nice, simple design. Jesse! I built a separate loop with filter and pump and regularly run when sailing. I located it just in front of the starboard propane locker. It's amazing how much more junk is picked up during and after a sail. I strongly suggest using a higher micron rating filter during your first hours of sail. I'd start with 30 until you've collected all of the bug globs over several sails. A 30 micron will work well, but probably won't clog so much to strain your pump and maybe shut you down. Carry plenty of spares... /Ed
 

DArcy

.
Feb 11, 2017
1,691
Islander Freeport 36 Ottawa
A couple of years ago I had problems with clogging filters. It got pretty bad to the point I had to change them every couple of weeks. After the boat had been sitting calm for a few days I pulled the fuel filler line and the fuel sender off the top of the tank, held a light in one and pointed the wand from my Pella 6000 oil extractor down to the bottom of the tank. I pumped up a vacuum in the Pella and waved the wand around slowly scraping the bottom of the tank. I was amazed at how well it sucked the gunk from the bottom of the tank, into the oil extractor. Very satisfying to watch.
I put the dirty fuel in a Jerry can and found a service station that would take it off my hands.