YM Article Biodiesel warning to boat owners

[[70521]]

I read with interest the arcical in YM - Biodiesel warning to boat owners and wondered if anybody had actually suffered from this as I've not seen thousands of vessels marooned off the coast of the UK with conked out engines.

 

[thinwater]

Interesting.

The FAME part reads a bit like an infomercial from Marine 16. He has a vested interest in finding a problem, blaming someone, and selling the solution.
The metals it is reacting with are copper fuel lines, which ASTM, ISO, and all engine manufacturers will tell you are a bad idea for stand-by generators and other applications where the diesel just sits. Yachts, for example. Copper is an oxidation catalyst for diesel. Copper and fuel breakdown

ASTM D975 Appendix X2.7.2: Fuel Storage Conditions
Copper and copper-containing alloys should be avoided. Copper can promote fuel degradation and may produce mercaptide gels. Zinc coatings can react with water or organic acids to form gels which rapidly clog filters.

Cat installation guidance.
Material. Black iron pipe is best suited for diesel fuel lines. Steel or cast iron valves and fittings are preferred.
CAUTION: Copper and zinc, either in the form of plating or as a major alloying component, should not be used with diesel fuels. Zinc is unstable in the presence of sulfur, particularly if moisture is present in the fuel. The sludge formed by chemical action is extremely harmful to the engine’s internal components.

Cummins installation guidance.
Diesel Fuel Piping. Diesel fuel lines should be constructed from black iron pipe. Cast iron and aluminum pipe and fittings must not be used because they are porous and can leak fuel. Galvanized fuel lines, fittings, and tanks must not be used because the galvanized coating is attacked by the sulfuric acid that forms when the sulfur in the fuel combines with tank condensate, resulting in debris that can clog fuel pumps and filters. Copper lines should not be used because fuel polymerizes (thickens) in copper tubing during long periods of disuse and can clog fuel injectors. Also, copper lines are less rugged than black iron, and thus more susceptible to damage.

Note: Never use galvanized or copper fuel lines, fittings or fuel tanks. Condensation in the tank and lines combines with the sulfur in the diesel fuel to produce sulfuric acid. The molecular structure of the copper or galvanized lines or tanks reacts with the acid

and contaminates the fuel.

Yanmar manual
piping is specified as rubber or steel (page 9).

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As for e10, we've been living with that in the US for 3 decades. Some rant and rave, but managed properly it works just fine. Yes, it will corrode carb bowls if the gas is allowed to absorb moisture and not treated with one of a few effective additives.
Biobor EB, Stabil Marine 360, and Merc Store and Start are very effective against corrosion (independent testing). Most of the others are snake oil.

 

[KompetentKrew]

I saw a very small amount of bug in my fuel pre-filter when I changed it 18 months ago, but nowhere near the amount in the photo in the article - just a strand of brown phlegm.

I had a leak from the filter at the time, and had to replace it and bleed the system, but I don't think the bug was cause of it - the thought had never occurred to me before.

Whilst on the hard over the last year I ended up with a couple of litres of diesel (perhaps as much as 4 litres) in the bilge beneath the engine, due to a leak I struggled to track down. I left the fuel in there for months, thinking it unimportant, and when I came to bail it out and dump it I found that the bug had run wild. My bailer and the bucket I used to transport the fuel from the boat to the boatyard's dumping tank are both spotty with it, and the dry bilge now has a sticky brown bottom.

I'm sure that in the past I've read people on here talk about diesel bug as if it's a myth and nothing to worry about, but I am now much more conscious of it and will probably start dosing with additives.

 

[westernman]

I had diesel fuel bug some 15 years ago from red stuff from Gibraltar.
Some heavy doses of the usual things managed to kill it off. I changed filters a couple of times and no problems since.

I am pretty sure that the white fuel we get down here (Spain/France) includes some bio-diesel as it does for cars.
The places where I fill up for the last 10 years or so all do a roaring trade. So the stuff I get is fresh and clean.

I have not taken any particular precautions, no additives or any else.
No bugs or issues.

 

[billyfish]

Not to be taken lightly, found this in the bottom of the tank after the engine stopped in the middle of lyme bay last summer. Luckily I have sails and there was a breeze. Mind you sailing into Brixham was interesting ?

 

[tudorsailor]

We conked out mid channel in the Ionian last season. I had been dosing with Marine 16 but I had had crud on the tank wall that blocked the inlet. I spoke to Mr Marine 16 He said that they have changed the formulation in light of the increased bio-diesel in Greece. In addition he said that UK tend to use reprocessed cooking oil compared to parts of Europe which use virgin rapeseed oil for biodiesel.

I previously had the course strainer that was around the pick up removed. It is now back in place. I also added the latest version of Marine 16.

The guys in LEfkas said that they were seeing increasing problems due to the increased percentage of bio-diesel in the fuel
I will inspect the diesel on my return in May. Hopefully I will not have to discard yet more diesel
TS

 

[Graham376]

Reading the comments about copper pipe, I do wonder how my boat and tens of thousands of others have managed for decades without problems. Also, I'm told modern diesel is low sulphur.

 

[penfold]

Not even that, it's all ultra low sulphur now.

 

[Mistroma]

We conked out mid channel in the Ionian last season. I had been dosing with Marine 16 but I had had crud on the tank wall that blocked the inlet. I spoke to Mr Marine 16 He said that they have changed the formulation in light of the increased bio-diesel in Greece. In addition he said that UK tend to use reprocessed cooking oil compared to parts of Europe which use virgin rapeseed oil for biodiesel.

I previously had the course strainer that was around the pick up removed. It is now back in place. I also added the latest version of Marine 16.

The guys in LEfkas said that they were seeing increasing problems due to the increased percentage of bio-diesel in the fuel
I will inspect the diesel on my return in May. Hopefully I will not have to discard yet more diesel
TS

My boat has been sitting in the Ionian yard since Oct. 2019 with approx. 30 litres of fuel in the tank. I had checked the small sump and double dosed with Marine16 before lifting out and only found small amounts (possibly 20-30mls) of usual diesel degradation products (dark, oily, thicker than diesel and some black flecks with similar consistency).

I checked in October 2021 and only found a small quantity of degradation products, no bug as far as I could see. No water in the sump and wiping side of the tank and base didn't show any "slime".

I added some more Marine16, swirled the fuel around and ran the engine for a short time. I'm pretty hopeful that the fuel will still be fine when I check again in May 22 after more than 2.5 years storage.

I have a plastic tank and Yanmar engine with their standard hoses and metal pipework.

 

[thinwater]

Reading the comments about copper pipe, I do wonder how my boat and tens of thousands of others have managed for decades without problems. Also, I'm told modern diesel is low sulphur.

Uhhh. According to the above they do have problems.

It is just a factor, not a certainty. Many factors combine, including FAME content, retention time, water content, and even cross contamination with ethanol (yes, it happens in transit). If the fuel is burned through within 6 months and reasonably dry it will not be a problem. But it can be with boats that only go out a few times each year, burning only a few gallons.

BTW, there is no "usual" degradation" of good diesel in less than 5-7 years. Seriously, we run those tests all the time. Keep a sample in a sealed glass jar and compare. Anything you see is probably bug or catalyzed oxidation and is not "normal."

 

[[70521]]

The FAME part reads a bit like an infomercial from Marine 16. He has a vested interest in finding a problem, blaming someone, and selling the solution.

My thoughts exactly.

 

[Mistroma]

BTW, there is no "usual" degradation" of good diesel in less than 5-7 years. Seriously, we run those tests all the time. Keep a sample in a sealed glass jar and compare. Anything you see is probably bug or catalyzed oxidation and is not "normal."

That's what I've found with stored diesel. I've never had an issue with diesel stored in containers over the winter. I checked some I had in storage since August 2019 and it was still clear in late Sept. 2021. No surprise there at all.

The usual degradation I mentioned was in reference to fuel in my tank. It has been heated repeatedly in use, my tank gets pretty hot on long runs with hot fuel returning to the tank. The small amount left has been sitting in the tank a lot longer than usual, 2.5 years instead of 6 months. I was indicating that it was no worse than I'd expect after only 6 months. i.e. The additional 2 years storage didn't make matters worse and I only saw the usual amount.

I stored some of the residue I removed in 2018 in a small bottle kept in the dark. It was completely clear by start of 2019 season with dark oily residue at the bottom. I added a few mls of boiled water, sealed it and left it until the end of 2019. It remained clear and I saw no sign of microbial growth sediment at the bottom in Sept. 2021. This seemed to confirm that the residue wasn't "bug". I shook the bottle before leaving and it became cloudy with a few mls of water in the bottom. I will check again in April. It is reasonable to assume that Marine 16 has inhibited growth of any existing bugs in the fuel, even after adding some boiled water.

I have always assumed that the degradation is initiated as the fuel is pumped around the engine, heated and returned to the tank. I remove some residue from the sump at the end of each season and again at the start. It seems reasonable to assume it is just settling out over the winter. I've assumed that the residue I see is more akin to asphaltenes than a product of microbial action (i.e. initiated by heat and accelerated by other factors. I never used to find any residue but it has steadily increased since 2012, luckily still only a pretty small amount.

It is also worth noting that I've seen no sign of significant water due to the tank "breathing" with daily temperature changes over the last 2.5 years. I'm careful to seal the cap o-ring and the plastic tank is less prone to condensation than a metal one.