The guys on my dock (old guys included) swear by the use of automatic transmission fluid as a fuel additive (1 quart per 40 gallons of diesel). They claim it acts as a biocide (algae killer) and as an added bonus, lubes all internal engine parts. They claim it burns like diesel and you can't overdose as an additive .
What do you think before I add a $4.00 quart to my 35 gallon tank..
—
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
I would not do it.
I would use a dedicated diesel treatment that acts as a fuel stabilizer as well as a biocide.
There is no down side to using a prescribed fuel treatment for fuel and ATF in the tranny.
Not one.
From Golden Eagle's website:
"Protect Diesel Engines from Microbial Contamination
Diesel fuel degrades with time, causing darkening of the fuel, as well as sludge and sediment formation within the fuel tank. These issues are even more prevalent in bio-diesel and Ultra Low Sulfur Diesel (ULSD) fuels. This can lead to the plugging of filters, starting problems, poor engine performance and reduced engine life. Diesel Formula Sta-Bil keeps diesel fuel fresh, promotes thermal oxidative stability and removes water from the fuel tank, which helps limit corrosion and inhibit the growth of bacteria, fungus and algae that require water to grow. It also contains extra lubricity and detergents to protect and clean your entire fuel system.
The Dangers of Microbial Contamination
Diesel fuel degradation is a direct consequence of microbial contamination. Possible results of microbial growth in fuel tanks includes the accumulation of sludge and sediment in fuel, reduced combustion efficiency, elevated pour point and cloud point, poor detergency, increased corrosion of fuel components and plugged fuel filters. Microbial contamination of fuel is caused by two main groups of microorganisms: bacteria and fungi. Just like all living things, bacteria and fungi require food and water. Diesel fuel is their food, and an ample supply of water can often be found at the fuel-water interface of your tank. The first key to keeping fuel clean and microbe free is to minimize the water available to these pests. Although fuel monitoring and system maintenance are excellent ways to do this, they also require more advanced skills and can be time consuming and expensive. A better way for the average diesel driver is Sta-Bil Fuel Stabilizer - Diesel Formula. Just pennies worth in your fuel tank at fill up can save you hundreds of dollars down the road in repair and extra maintenance costs.
Key Features
Here's a conversation that my interest you as well: https://www.catalina36.org/forum/technical-discussion/getting-cabin-star...
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
ATF is not meant to be burned, so I'd say use caution here. Some folks swear by 2-stoke oil as a diesel additive -- at least it's designed to be burned. With all additives, you gotta ask what is trying to be accomplished. Most fall into (1) cetane boosters to help burn, (2) control moisture to reduce biological contamination, (3) improve cold weather attributes, (4) clean and lubricate fuel delivery components.
I'd say stay away from anything not designed specifically for diesel fuel. My suggestion is to spend $8 on something designed to treat an identified fuel issue vs $4 that is not a fuel treatment at all.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Nope. Don't do it.
WHY on god's green earth would you want to even consider the risk to your engine when there are economical and proven biocides on the market??? Makes no sense. At all.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Note: I was going to be even more blunt than that, but I decided to clean up my act.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Coast Rider, I believe your tank is a 25 gallon tank, not a 35 gallon tank. Nevertheless, it would help all of us to help you if you would place your vessel details in a signature. That way we could offer you more targeted advice without having to guess the age of your boat, which is presumably a Catalina 36. (Otherwise why would you be here?)
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Hi Larry,
A 35 gallon tank was installed in Oct 2002 in my Catalina 36. This date, the mfr, capacity, etc, etc. is marked on top of the tank. Several other modifications were made as well. bought the boat last August. No, I haven't used ATF in my tank. The others on my dock did. I appreciate your blunt advice and will not use ATF as a fuel additive. UPS delivered my Biobor today. Will use this. Updating my vessel details is great advice.
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
I think biocides/fuel treatments are only half the equation.
The other is the condition of the fuel cap and accompanying o-ring, which seal out debris and water.
I would double check that too.
I want to swap out the the plastic deck fitting with a chrome-over-bronze Perko deck fitting.
Getting away from the plastic is a smart thing to me.
I have a new 32 gallon tank I just installed from Catalina Direct.
I replaced the the fuel fill hose too; it was 1.5" fuel hose with wire reinforcement.
And made in Italy. It was not cheap.
But probably very good quality.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
MitchMan,
You really think that much water leaks into the tank? How about a simple O ring or rubber washer under the plastic cap ? I'm poor after about 6k in repairs since Aug. Also, we probably don't get as much rain in So. Cal as you in TX.
I think I'll polish the fuel and clean the tank after one week of Biobor treatment and change the fuel filter.
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Joe,
Water can be absolutely "funneled" into the fuel tank. A loose fuel cap or cracked or missing o-ring could set up a fuel-cap leak scenario.
If you notice in a rain storm that water can be funnel into your fresh-water tanks by removing the fresh-water-tank deck-fill caps. This is a cool design feature that could be exploited calm seas if a squall passed through. First, let the rain clean your deck then pop the fresh-water deck-fill caps and let the rain water fill your tanks. Very nice.
That same design attribute will fill your diesel tank if the cap is loose or if an o-ring falls out however.
I replace the cap every year or so. It's like $20.00.
Probably overkill, but, hey, it helps me sleep at night.
That and scotch.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
Coast Rider, I'll rest easier on your behalf now that you're not adding ATF to your fuel.
But you say a 35 gal fuel tank was added to the boat. Now THAT intrigues me. If you ever gain access to it for photography, how about sharing a couple photos with the rest of us?
Happy sailing.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
Here are the photos Larry....35 gallon tank on my 1986 Cat
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Hi Larry,
Mitchman installed a 32 gallon tank he ordered from Catalina Direct. See his posting above yours. I'll try to post a photo of my tank. Could be one reason my boat lists to port.
Joe of Coast Rider
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Joe,
Mitchman has a MkI, and a 32-33 gal tank belongs in it, just forward of the galley sink. Larry has a MkII, and the tank is 25 gal and port aft. Do you have a MkI or a MkII? It might help everyone if you complete your "signature" to let everyone know what you own and where you sail (it's under the My Account tab, just below the C36/375IA title at the top of the page). Just a thought.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Tom,
I have a 1986 Catalina M-25 universal engine. Originally had a 25 gallon tank upgraded to a 35 gallon in 2002.
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
[quote=Coast Rider]Hi Larry,
... Could be one reason my boat lists to port.
Joe of Coast Rider[/quote]
My 36 MkII only has a stock fuel tank and it still lists slightly to port (as do most C36's :)
---- Howard & Linda Matwick ----
--- S/V "Silhouette" - Nanaimo, BC ----
--- 1999 C36 MkII #1776 M35BC ---
based on the picture you are using for your avatar you have a MKl which would be the 32-33 Gal tank. As Larry and others have said you can update your information confirming what you have Year, Hull#, Engine, etc.
Gary Bain
S/V "Gone With The Wind"
Catalina 36', Hull #: 1056, Year: 1990, Engine: M-35
Standard Rig
Moored: Boothbay Harbor, Maine
Home: Auburn, Maine
Another way water can get in your fuel is though the tank vent line. As the engine is running unused fuel returns to the tank hot/heated. When the fuel cools it sucks in condensation. This is the best reason to keep your tank full. Less room for moisture filled air.
Chuck Lennox
97 MKii Ventura Ca
Island Girl Hull #1611