Sludge in the fuel tank

[s3raphim]

Hello,

I have a 1978 Cal 39 MkII here in Seattle, WA. She has a Perkins 4108 with dual Racor 75/500 FGX primary filters (10 micron), and a 2 micron secondary filter at the engine.

I had the filters changed last month and the mechanic who did the work said (about the Racors) that he'd never seen as dirty a filter. I figured this was because the previous owner hadn't changed it, and I was a year in to ownership. At any rate… just 1 month and 10 engine hours into the new filters, the engine died at sea and I had to emergency anchor and then get towed into my slip.

On inspection, the port side Racor filter was black and coated with a bit of dark sludge. I have a 2”” inspection port at the top, and was able to take a photo inside the tank.

See photos below.

I replaced the filter myself, in an attempt to simply get the engine running, but the engine still won’t start.

It’s very likely that I didn’t bleed the engine correctly, or perhaps the sludge has gummed up the primary filter (which I haven’t changed), or the fuel injectors (please, Lord, no!).

My knowledge of bleeding the engine is strictly from researching online posts. I know enough to be dangerous, and it seems like a real chore. I was able to bleed the top fitting on the primary engine filter, and the fuel injector fittings themselves. I was NOT able to bleed the fitting at the top of the governor, as for the life of me I could not fit a wrench or socket into that small a space.

At any rate — my thoughts are to figure out or hire someone to properly bleed the engine, with new filters all around, just to get her running again… and then to immediately determine the scope of issues in the tank.

The tank is 57 gallons and about 15% full. I believe my error was in not keeping the tanks topped up over the winter, and I assume some sort of moisture has entered in.

INSIDE THE TANK


CLEAN STARBOARD RACOR


DARK PORT SIDE RACOR


PORT RACOR FILTER W/ SLUDGE


So the question becomes paying someone to polish the fuel and clean the tanks, or trying to do the grunt work myself.

Would love any thoughts/advice from people who’ve gone through this process in the past, or might have a recommendation of a person, service, or yard here in the Pacific NW to help.

And on that note, I would ALSO really love to find "a guy" who knows Perkins 4108's and who I could pay to spend a few hours training me on engine basics (filters, oil change, bleeding the system, pencil zincs, other misc maintenance issues).

Thanks in advance,

Sean
1978 Cal 39 MkII S/V AIOLOS
Seattle, WA

[s/v Moondancer]

I made a polishing system out of a cheap car inline 12 volt fuel pump, a household water filter system and some clear plastic tubing...Cost a total of $60 and a couple of days of stirring the tank and pumping from tank to tank. You could just pump into and out of 5 gallon jugs.

The problem is a 40 yr old tank with 40 years of accumulated sludge!

[Stu Jackson]

In addition to cleaning, you should also check if you have a ball style check valve on the INLET of your filter housings. I just learned about this the other day, as a result of forensics on a fuel starvation issue I had. After 33 years (!!! - imagine that!!!) there was a buildup of sediment, thick black gunk, that prevented the ball from operating and stopped fuel flow. I learned about this by reading the filter housing manual - RTFM. I removed the housing, opened the cap to the ball valve and cleaned it out.

[Lepke]

If you use enough fuel to continually add new fuel, then the additives that kill bugs and stabilize the fuel stay current. But if your fuel goes many months without refueling, you need to add a fuel conditioner. The better ones kill organisms that live between the water and fuel, stabilize the fuel components, add lubrication, help the Racor remove water, minimize soot, and enhance combustion.
To clean the tank, you can add an electric pump that pulls thru the racor and returns at least 30-40 gph to the tank. The 4108 doesn't return enough abundance of fuel to get ahead of the debris. Whatever fuel conditioner you use, start with a triple dose.
I use Archoil AR6200 and never have fuel problems. I also get about 6+% better mileage with it. Available online at archoil.com, Amazon, eBay and better fuel suppliers.

[Cheechako]

Yep polish your fuel. Keeping the level low may not cause sludge. Could prevent it actually, as the fuel doesn't get so old. Just a guess.
You can build your own pump/filter to polish, especially if you leave that tank with only a low amount of fuel. But it would be nice to get a good pro done flush of the tank and cleaning of the fuel. They use a pressure wand to clean the walls of the tank etc. Do it once, peace of mind.
They will want more fuel in the tank to do it. It's amazing how much yuck they get out of a tank...
I had it done in Seattle but it was many years ago.

[a64pilot]

Your not getting that out with a fuel polisher and if you try it’s likely you will spend more on filters than it cost to have it done.
If the tank is accessible, pump it out and clean it out with a bunch of rags, if you use any acetone be sure the area is exceedingly well ventilated and try to keep it off of your skin.
When you put new fuel in, use a biocide from now on and this won’t ever happen again.

It’s almost certainly “bugs” I just say bugs because mold, fungus and bacteria will grow in fuel, but algae won’t and often people mistakenly say it’s algae.
Fuel conditioner / stabilizer and biocide are different things, but it’s possible there are products that do both.
But biocide prevents or kills bugs, best to prevent because if for example you just kill them in your tank now, your going to get good at changing filters, because you have to filter all the dead ones out.
If you have the tank polished or clean it yourself, there will still be enough live bugs left to reseed a new colony in time, so be sure to put a biocide in with the new fuel.
Personally I put a half ounce of Biobor JF in with every 40 gls, and will never have a bug problem because of it.
If you let fuel sit, then you need a stabilizer, but apparently Startron enzyme stabilizer reduces fuel tank corrosion, so I add it too. It also apparently “gets rid” of water, which can only mean it emulsifies it and it’s burned, which really shouldn’t be an issue because ALL fuel has some water in it anyway.
‘Bugs” change the PH of fuel and make it acidic, this causes both fuel tank and fuel system corrosion

[SCarns]

Had a similar issue. Multiple solutions to my problem. You can read about my issue here: Fuel Fever – Nauticarazi

and here: http://nauticarazi.com/2020/01/29/th...ng-of-the-end/

If the sludge isn't too bad, you may be able to use StarTron Fuel Tank Cleaner available here: https://smile.amazon.com/Star-Tron-T...xpY2s9dHJ1ZQ==

You'll be replacing filters often regardless, so be sure to have extras on hand. It's better to have clogged filters than a clogged engine.

[JPA Cate]

And, here's a link to a thread about a very dirty old diesel tank in a CF member's boat, and how he approached cleaning it. https://www.cruisersforum.com/forums...ks-165234.html

[Pete7]

Sean, how much access do you have to the top of the tank?

The 2" hole you currently have isn't really enough to do a DIY clean, you need something you can get your arm in and see at the same time. Mine has a hatch probably 9" x 12" which enabled me to use a 2" wall paper scraper to really clean the bottom and side of the tank, scooping it into a cut down plastic bottle.

A pretty awful job but completed in an afternoon for the price of some rags and marigold washing up gloves. A quick wash with clean diesel the tank filled a good dose of fuel treatment has meant no further problems in 5 years.

So consider fitting a decent sized hatch to solve the problem once and for all.

Pete

[GWilly]

I’ve not had that serious a problem with my fuel tanks. But a few years ago on my previous boat I had the fuel polished by Fuel Care, up in Lynnwood. They did a nice job for me, took photos of inside the tanks, and gave me a 6-page report on their findings. They came to my boat at the marina with all their gear. Admittedly it wasn’t cheap but the PO had not done the additives to keep the fuel and tanks clean. I was glad I got it done.

[boat driver]

The sludge is an accumulation of years inside your tank. The short easy method to remove it would be bringing in a fuel polishing equipment. That includes getting the tank cleaned entirely inside, not just the bottom.

Another method is try a product called Fuel Right FuelRight.com manufactured in Delaware. Shock treat your tank and then have plenty of filters- it will emulsify the sludge and pass it out thru the filters.

This product is utilized in the commercial marine, heating and railroad industry- it is not really well marketed in the recreational industry.

Particularity useful when tanks are full (as yours) and difficult to get a polishing rig into the tank fill to remove the sludge, this method works very well. But it does cost in filters. I know a number of sailors who used the product and would rinse the racor filters in a bucket of diesel fuel and reuse them a number of times until the sludge thinned out. This only works on new filters.
try it.

[Flatswing]

1st clean the tanks, then polish the fuel. Short term - trying blowing air back into the tank from the Racor inlet, sludge may have blocked the pickup tube which is why you can’t restart. I doubt your secondary filter or the injectors are plugged.

[Uncle Bob]

Hi, as for the filters,primary is the first in line from the tank, which should be a larger filter than the secondary which is usually engine mounted just prior to the lift pump.
If you can get a sample from the tank and the material is granular in nature, somewhat like coffee grounds, which is soluble in metho you have asphaltenes, if not then you have years of accumulated sludge and possibly biological material.
I encountered this problem not long after the initial purchase of mine and ended up putting together a high volume pump and filter which I use to cycle the fuel approx once a year. I also installed an inline sedimenter between the primary racor and the tank. A commercial polishing company would achieve similar results (probably better) without the need to get your hands dirty
Having done this my problems are no more, I wish you well.

[lordgeoff]

Originally Posted by s3raphim

Hello,

I have a 1978 Cal 39 MkII here in Seattle, WA. She has a Perkins 4108 with dual Racor 75/500 FGX primary filters (10 micron), and a 2 micron secondary filter at the engine.

I had the filters changed last month and the mechanic who did the work said (about the Racors) that he'd never seen as dirty a filter. I figured this was because the previous owner hadn't changed it, and I was a year in to ownership. At any rate… just 1 month and 10 engine hours into the new filters, the engine died at sea and I had to emergency anchor and then get towed into my slip.

On inspection, the port side Racor filter was black and coated with a bit of dark sludge. I have a 2”” inspection port at the top, and was able to take a photo inside the tank.

See photos below.

I replaced the filter myself, in an attempt to simply get the engine running, but the engine still won’t start.

It’s very likely that I didn’t bleed the engine correctly, or perhaps the sludge has gummed up the primary filter (which I haven’t changed), or the fuel injectors (please, Lord, no!).

My knowledge of bleeding the engine is strictly from researching online posts. I know enough to be dangerous, and it seems like a real chore. I was able to bleed the top fitting on the primary engine filter, and the fuel injector fittings themselves. I was NOT able to bleed the fitting at the top of the governor, as for the life of me I could not fit a wrench or socket into that small a space.

At any rate — my thoughts are to figure out or hire someone to properly bleed the engine, with new filters all around, just to get her running again… and then to immediately determine the scope of issues in the tank.

The tank is 57 gallons and about 15% full. I believe my error was in not keeping the tanks topped up over the winter, and I assume some sort of moisture has entered in.

INSIDE THE TANK


CLEAN STARBOARD RACOR


DARK PORT SIDE RACOR


PORT RACOR FILTER W/ SLUDGE


So the question becomes paying someone to polish the fuel and clean the tanks, or trying to do the grunt work myself.

Would love any thoughts/advice from people who’ve gone through this process in the past, or might have a recommendation of a person, service, or yard here in the Pacific NW to help.

And on that note, I would ALSO really love to find "a guy" who knows Perkins 4108's and who I could pay to spend a few hours training me on engine basics (filters, oil change, bleeding the system, pencil zincs, other misc maintenance issues).

Thanks in advance,

Sean
1978 Cal 39 MkII S/V AIOLOS
Seattle, WA

You have a very simple problem. Start at your fuel Tank(s).
1. Dump the fuel (responsibly).
2. Flush the fuel tank. If you don't have a convenient drain cock on the tank then install one.
3. When the tank is empty Flush again with fresh diesel or kerosene. Drain again and flush with hot soapy water.
4. Remove and dismantle your Racor units. Thoroughly clean as above. Reassemble and fit a new filter.
.5. If practicable flush the fuel line to the engine and flush the return line (not back into the tank)
6.Renew all other filters.
7. Add an overkill of Diesel Biocide to the fuel tank.
8. Refill your fuel tank using jerry cans of fuel from a reputable automotive Fuel station.
9. Loosen a couple of fuel lines at the injectors to bleed the fuel system. There is a "lifter" somewhere as the fuel line gets to the engine.
It is unlikely you will have trouble starting.
Make sure every time you put fuel in the tank add Biocide and yes where possible keep the tank full when not in use.

[Nicholson58]

Bigger inspection port would be nice.
Definitely polish what you have or dump it.
I used a putty blade in our tanks and followed with a pressure washer with a customized twisty pipe to reach.
Remove disassemble clean your Raycors.
I installed a continuous 45 gph circulating pump with a large 1 micron element. My main intake to the Raycors comes from this super clean fuel loop, not the tank.
The #1 source of water is a cracked O-ring on your deck fuel port.