Diesel Fuel Polishing - Catalina 270

[PaulDaniel]

I know much has been written on this topic. It seems everyone approaches this slightly differently. My fuel tank does not have an inspection port, so it is impossible to completely clean out the tank.

Here are some strategies that I have read about or thought of:

1) Don’t polish it. Just keep a lot of extra filters available and be prepared to use them.
2) create portable standalone fuel polishing system with fuel pump, filter, and wand, so that you can polish the fuel tank whenever you feel the need.
3) create onboard fuel polishing system that you can run whenever you want at the press of a button. (This is mostly just appropriate for cruisers who have to routinely get diesel from questionable sources)
4) instead of creating a separate fuel polishing system, just pump out the diesel from the outlet of the racor filter that is already on your boat. (You could use a drill pump for this). If concerned, you could cycle it several times.
5) instead of filtering the diesel, just syphon or pump it out and dispose of it, and put in fresh diesel.
6) instead of trying to clean out a moldy rusty tank with no inspection port, just buy a new fuel tank (cost about $1k not including labor)

I just bought the boat. I haven’t had any fuel filters clog up but I haven’t had it very long. The previous owner had fuel sitting in the tank for 7 years so I assume there is growth in it. I am inclined to use method 1, 4, or 5. I bought Biobor JF and Startron to use as fuel additives. But I’m concerned that adding them will dissolve a LOT of stuff that is going to clog my filters. Perhaps instead of polishing the tank, I can just start using additives and keep a lot of filters on hand?

 

[Ralph Johnstone]

Maybe back up to a little before you first paragraph. If you don't have an inspection port, you could install one of the add on devices on the top of the tank. That wouldn't be my first choice however as diesel has a terrible history of leaking on gasketed surfaces. What I did install was a small SS disk with a 3/8" NPT plug and the usual telon tape and thin layer of Permatex #2 sealant on the plug which I've never seen leak yet:

The stuff oozing out of the underside of the SS disk is a good dose of Permatex #2.

Every couple of years I'll pull the 3/8" plug and run a small tube from my Pelor vacuum oil pump down into the bottom of the diesel tank and pull a long continuous sample. The small vacuum tube comes up through a short length of clear 1/2" vinyl tube and I check for crud in the fuel as it slowly goes through the larger dia. vinyl tube. I keep dragging the tip of the tube along the bottom of the tank checking for algae. The small Pelor tube has a thin piece of spring wire in it to guide it to where you want it to go. I have not seen a sign of algae in 27 years nor a trace of dirt in my primary filter after a change.

Maybe the lack of dirt is from clean living, or the BioborJF that goes in after every fuel fill up ? ? ?

 

[kappykaplan]

Maybe the lack of dirt is from clean living, or the BioborJF that goes in after every fuel fill up ? ? ?

My vote is for the latter, Ralph!

 

[Ralph Johnstone]

My vote is for the latter, Ralph!

Hmmmm. Guess you've seen me on Saturday nights then ?

 

[kappykaplan]

Hmmmm. Guess you've seen me on Saturday nights then ?

Maybe . . . Can't be 100% sure.

 

[Davidasailor26]

If the old fuel has been sitting for 7 years I’d consider pumping it out and starting fresh. Doing that with the amount of fuel a 27’ boat can hold probably won’t be prohibitively expensive. Having said that, it might not prevent all problems if there is growth stuck to the tank itself. Maybe replace the fuel then keep an eye on the filters for the first few hours of runtime after that. If they start clogging you know there’s a problem inside the tank and you can get it professionally cleaned. If you plan on taking a trip where engine loss would be catastrophic before you get a chance to watch the filters then maybe be more proactive.

 

[PaulDaniel]

Right on.

There was maybe a 1/4 tank of old fuel, and the he topped it off with another half tank before I bought the boat.

I don’t think there are any professional services around me that will polish the fuel. I’m on a small lake with no big marinas or boat yards.

I think a reasonably approach that is proactive without going over the top or creating extra work for myself would be:

1) add Biobor and Startron to existing fuel (maybe let it sit for a day to bust up some grime)
2) empty tank by pumping fuel from the outlet on the existing racor 10 micron filter
3) perhaps cycle the fuel like this a handful of times, while changing filters as necessary
4) when satisfied with fuel cleanliness, call it a day.
5) continue using fuel additives and keep a handful of extra fuel filters on hand

Y’all tell me if this seems like a bad idea. I like this plan because I don’t have to build any fuel polishing system. It may not completely clean all of the (assumed) gunk in the fuel tank, but it seems like it would get most of the bad stuff out and give me a good start.

 

[PaulDaniel]

Ralph,

I would love to have an inspection port in my fuel tank. This might be a dumb question, but how do you cut an inspection hole or pipe fitting without getting metal in the tank. I assume this would be unavoidable and you would have to filter the fuel and clean tank after installing an inspection port.

Thanks y’all.

 

[jssailem]

I don’t think there are any professional services around me that will polish the fuel.

You might croak at the cost they would quote. I have two 85-gallon tanks. They wanted $2500 per tank in 2016. I took a pass.

 

[Ralph Johnstone]

but how do you cut an inspection hole or pipe fitting without getting metal in the tank.

The metal cuttings are pretty hefty compared to the microscopic garbage that normally floats around in your tank. You've got two filters to deal with this IF the particles ever get lifted into the fuel through wave action so ignore them. They're big and they don't plug filters.

The rest of your ideas for n the fuel seem like a good idea but maybe take a good book with you to pass the time.

Having hypothesized all that, maybe put some time in to getting a peek into the tank to determine what IS in the tank. Every so often one gets lucky .

 

[jssailem]

What type of metal was used for the tank?
You can use a hole saw to cut the hole. You can use a vacuum to suck up the metal while cutting the hole.
Not perfect, but doable. If the metal is magnetic, a magnet can be dropped through the hole to pull up any shavings. The fuel filter will capture any big pieces that find their way into the fuel lines.

Your approach is reasonable. You might go out for a sail to stir the tank while the additives do their thing.

 

[ice breaker]

An easy way to gain access to the tank is to pull the fuel sender. Generally it is 2 inch hole. It will give you a chance to look around and see if you have a problem. Generally, all boats have a list, so the crud tends to settle in one spot. On our boat, after we purchased it, it had cruddy fuel. So I used an oil extractor to vacume up the crud from the low spot. It solved our issue, and with aggressive amounts of bug killer no re growth.

 

[Foswick]

You might croak at the cost they would quote. I have two 85-gallon tanks. They wanted $2500 per tank in 2016. I took a pass.

OK, those are big tanks but not THAT big! I'm in the wrong business.

 

[jssailem]

I think the former owner wanted to be able to get to Alaska and have fuel to get home. According to my calculations I can head for Hawaii and if the winds die, have enough fuel to power back into the winds for about 1300 nm.

I have never filled both tanks.

 

[colemj]

I don't know the Catalina 250, but when I looked it up, every source said it had a 6gal portable tank. I assume this was for an outboard, and they also offered the boat with an inboard diesel option? The Catalina Direct website does show an aluminum replacement tank with inspection port.

So a few questions:
1. Are you sure your tank is rusty? If so, it isn't aluminum.
2. Are you sure there isn't an inspection port - maybe on the other side of a bulkhead where you don't normally see it?
3. Is the tank easy to remove?
4. Just to be clear: the fuel is diesel and not gasoline, correct? You didn't specifically mention which fuel, and Biobor and Startron also make gasoline additives. I'm assuming diesel below.

If the tank is easy to remove, take it out to deal with it. If it is rusty, throw it away and replace it with plastic or aluminum. The tanks that Catalina sells are 14 and 17 gallon, so if yours is around this size, the amount of fuel you are dealing with is easily accommodated with jugs, and not hard on the wallet to toss and replace.

Treatment with Biobor and Startron won't remove much of any stuff cemented to the sides now. That will need physical removal, or you will continue to experience it sloughing off and causing problems over time. It will also take more than a day to work, and combined with physical agitation, the time to get it clean this way would be impractical.

If you have a sender in a 2" hole, it is possible to use a gear pump and small diameter tube to recirculate fuel at enough pressure to blast the crud off the walls. A 14gal tank might not even have baffles, so this makes the method more effective. It is even a large enough hole to get a small scrubber pad on a stick to reach a lot of the tank.

If you have space where you can access an inspection port, these are easy to install and will make cleaning the tank easy: Seabuilt - Access Plate Systems . They don't leak, so no worries there. Any metal shavings would just be cleaned or vacuumed out after cutting the access hole. The entire point of adding the access plate is to clean the tank.

The one plan option you don't want to do is just leave it alone and carry a lot of filters. This is a recipe for getting into trouble at the wrong time and place.

Mark

 

[colemj]

You might croak at the cost they would quote. I have two 85-gallon tanks. They wanted $2500 per tank in 2016. I took a pass.

Holy crap! In Caribe countries, fuel polishing is common and usually cheap. Particularly South and Central America. They aren't necessarily marine-specific, as there are a lot of polishing trucks that go around industrial places that just come to a marina/yard as another place. A friend here in Panama just had one of these services remove the fuel from his 200 gallon tank through a polisher, manually scrub the inside of the tank spotless, and put the fuel back in through the polisher for $200.

Mark

 

[WayneH]

OK, Maybe I'm just lucky. I have had my boat since 2011, never bought fuel from shady places and never used fuel treatments. The engine is a 1980 Westerbeast W50. Hurricane Sally put us on the hard for two years with repairs and retrofits. So the fuel has sat a bit. Last year I finally replaced the fuel sender unit. While the sender was out, I dipped a clear plastic tube into the bottom corner of the tank and pulled out about a 1/2 gallon of liquid which was all pink with no clumps. The local place where I get fuel now services quite a few Snatch Yachts so their fuel has a decent turnover.

All that said, when we were planning our trip to the Bahamas, I stocked up on fuel filters in case the only place to get fuel had a dock with missing boards and rusty nails sticking out.

 

[PaulDaniel]

Awesome replies. Thanks everyone!

Colemj,
The boat is a Catalina 270 (not 250) with a Perkins M20 diesel and a 14 gallon fuel tank.

My dock neighbor who has extensive diesel experience advised me to just keep some extra fuel filters handy and don’t create any extra work for myself. This is a VERY tempting idea! I’ve run the motor for about 10 hours since buying it and no problems that I can tell. I only do day sails on Lake Somerville which is about 10,000 acres. The farthest I go from the dock is about 5 miles. I do like to sail when the wind is 20-30 mph and the waves are 2-4 feet on the leeward side of the lake. But I would think in that case if my motor failed I could just drop the anchor. I guess it’s time to buy a bigger Rocna or Mantus anchor. I have a 10 lb Mantus Supreme which is undersized for higher winds. It came with a Danforth that I would say is perhaps 15 lbs. but I like the spade style anchors.

 

[colemj]

Awesome replies. Thanks everyone!

Colemj,
The boat is a Catalina 270 (not 250) with a Perkins M20 diesel and a 14 gallon fuel tank.

My dock neighbor who has extensive diesel experience advised me to just keep some extra fuel filters handy and don’t create any extra work for myself. This is a VERY tempting idea! I’ve run the motor for about 10 hours since buying it and no problems that I can tell. I only do day sails on Lake Somerville which is about 10,000 acres. The farthest I go from the dock is about 5 miles. I do like to sail when the wind is 20-30 mph and the waves are 2-4 feet on the leeward side of the lake. But I would think in that case if my motor failed I could just drop the anchor. I guess it’s time to buy a bigger Rocna or Mantus anchor. I have a 10 lb Mantus Supreme which is undersized for higher winds. It came with a Danforth that I would say is perhaps 15 lbs. but I like the spade style anchors.

I guess I answered before being fully coffee'd up because I swear your profile said C250.

I also didn't comprehend your description that you don't have any problems now, but only assumed it had growth. Now that I've correctly dosed myself, I agree that you should either confirm there is no growth by looking in the tank, or just wait and see.

If your tank has a gauge sender, pull that and look. Otherwise you could send a borescope down a fuel line return fitting, or the fill fitting.

Did you check for an inspection port like the Catalina website shows on the 14gal tank?

As far as the motor failing, that's not much of a problem out on the water. It's more of a problem when it happens as you are motoring in a fairway of slips.

Mark

 

[shemandr]

When I had gas problems with my A4 on my Ranger 29, I removed the tank and took it to a radiator place. They cleaned it and I re-installed it. I have to admit it was pretty easy to access that tank. And, I was having problems with engine stalling including one time entering Three Mile Harbor which nearly led to my boat being on the jetty.