Spare fuel cans

This is from the PBO website article on diesel bug treatments:

"Diesel bug thrives at the interface between fuel and water – ie just off the bottom of the tank, where the micro-organisms form colonies. In this cosy environment they break down the alkanes in the fuel using oxygen from the water, precipitating a black sludge to the bottom of the tank as they do so."

https://www.pbo.co.uk/gear/12-diesel-bug-treatments-tested-43353

Richard

We all know this, the OP knows this too, he said so in post 1.
 
Theory aside, it may be useful to know that I have hade two full cans of diesel which I am sure were water-tight which have both contained bacteria after a few months.
 
Theory aside, it may be useful to know that I have hade two full cans of diesel which I am sure were water-tight which have both contained bacteria after a few months.
How did you find out? Is it possible it was contaminated before? We’re the 2 cans airtight?
... just want to now if I should check my spare before launch, and how.
Also, I get my cans from local Shell garage. Is this better or worse than marina? Generally.
 
We all know this, the OP knows this too, he said so in post 1.

The OP did not mention oxygen at all. :confused:

Diesel bug is not anaerobic so keeping out oxygen will stop its growth .... and that is all I ever suggested. :)

I really do not understand why you are being so unnecessarily aggressive towards me when I'm just trying to enjoy what would have been an interesting technical discussion.

Richard
 
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It's my understanding - from explanations of the aviation practice of refilling aircraft tanks as soon as practicable - that the existence of an airspace above the fuel which is repeatedly 'refreshed' by means of a breather tube permits some water-condensate to form on the tank walls which sinks to the bottom. However little this might seem, over time this permits successive generations of d'bug to be spawned, multiply and die. Whether the sludge which accumulates is a by-product of the 'digestion' of hydrocarbons or the minute corpses of the organisms is a matter of detail. The consequence is that such sludge has the potential to clog fuel filters, starving engine(s) of fuel at usually a very inconvenient moment.

That has brought down several aircraft.
 
The OP did not mention oxygen at all. :confused:

Diesel bug is not anaerobic so keeping out oxygen will stop its growth .... and that is all I ever suggested. :)

I really do not understand why you are being so unnecessarily aggressive towards me when I'm just trying to enjoy what would have been an interesting technical discussion.

Richard

Diesel bug is a whole soup of mould, bacteria, funghi and other random slime which live off each other.
Some anaerobic, some aerobic.

Also over months, the diesel can start to break down. Diesel is a mixture too.

Best advice, from fuel co's and others is to not store it more than is really necessary.
 
I discovered bacteria in the cans when I opened them up to top up with the intention of topping up my tank. I think it is quite possible that the fuel from the marina was contaminated although I always use a funnel filter. The fuel was bought from the marina in Santa Cruz on the island of La Palma in the Canaries. Every marina I know insists their fuel is clean. The cans were air tight as far as I can tell. If I were you I would always fill cans from vehicle fuel stations rather than from marinas. That is not possible for me as I either travel by boat or on foot.
 
The villains of the piece:


Clostridium sp are obligate anerobes - they can only function in the absence of oxygen; desulphotomaculum doesn't use oxygen, but can tolerate it. Don't know about the others, but IIRC, dredging my memory from working as a lab tech nearly 50 years ago, pseudomonas is an obligate aerobe - it needs oxygen.

Basically, it doesn't matter if there's oxygen or not, if the wrong bugs get in your fuel, you've got problems. Yes, AFAIK, you need water, but not a lot, and I wouldn't bet on any tank being entirely water free.
 
Yes, AFAIK, you need water, but not a lot, and I wouldn't bet on any tank being entirely water free.

I don't know whether all fuel station tanks all have water in them or not, but it's certainly possible for boat fuel tanks to be entirely water free, other than the water which is dissolved in the fuel but, as I understand it, that's not the interface that the bugs need. :)

Richard
 
The secret to clean diesel is largely to do with sourcing good water-free non-FAME (bio) diesel and storing it in clean cans. Many marinas stock it. The reason is FAME contains methyl esters which being intensely hygroscopic are predisposed to absorb significant amounts of water.

Pure mineral diesel by comparison is less hygroscopic, allowing excess water to separate into a distinct layer at the bottom of the tanks where it can be drained off, centrifuged out, etc. For this reason the goal of keeping tanks completely water-free requires absolutely top quality water free FAME-free diesel. This is possible, but difficult, as much of the diesels available today are 100% water saturated.

Worse, being bio-degradable, FAME provides a read source of nutrients for microbes, a sort of handy bug larder! Together with the water held in suspension an ideal environment is created for microbial growth (anaerobic and aerobic) in different parts of the tank. This includes the bacteria, bugs, moulds, yeasts, slimes, and scums we collectively call diesel bug.

All in all, it’s best to disinfect cans regularly and then use the diesel within its designated lifespan. This is much shorter in the case of FAME inclusive diesels.
 
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The problem is known to be widespread wherever hydrocarbon fuels are stored and has been researched since the early 1950s. While the most prolific culprit would seem to be a beastie named Cladosporium resinae, there are many others. One of many studies which turned up in a simple web search ( http://nzetc.victoria.ac.nz/tm/scholarly/tei-Bio19Tuat01-t1-body-d4.html lists 21 forms of Bacteria and 25 forms of Fungi identified in sludges of varying sources.

It emerges that bioethanol-rich fuels are far, far worse at absorbing water from air vapour than unimproved fuels - especially so in humid environments - thus assisting proliferation of the 'bug soups'. This is relevant to our available diesel products.

You'll forgive, I hope, for my not searching much deeper, for 'life's too short' for much of that....

So, gentlemen and others, would it be a fair generalisation to suggest that a prudent leisure mariner would give some thought, from time to time, to ensuring his/her/its spare fuel cans are made scrupulously clean.....?
 
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So, gentlemen and others, would it be a fair generalisation to suggest that a prudent leisure mariner would give some thought, from time to time, to ensuring his/her/its spare fuel cans are made scrupulously clean.....?

Yep, and also used regularly. I used to carry a can of diesel on board, but it was lost in the bottom of a locker until I needed it one day. I got lucky and didn't have a problem, but I'm guessing the fuel was getting towards five years old. I wouldn't want to rely on fame-laden road diesel that old!
 
So, gentlemen and others, would it be a fair generalisation to suggest that a prudent leisure mariner would give some thought, from time to time, to ensuring his/her/its spare fuel cans are made scrupulously clean.....?

You'd have to be a bit of a gambler not to agree with that. I even make sure that the fuel can for my lawnmower is scrupulously clean. ;)

Richard
 
You'd have to be a bit of a gambler not to agree with that. I even make sure that the fuel can for my lawnmower is scrupulously clean. ;)

Richard

I tend to assume that cans are not perfect and don't pour from them without looking at the fuel first, and don't pour the dregs in without looking.
 
Diesel fuel can contain dissolved water albeit at parts per million level. The hotter the diesel the more water it can contain in solution. Of course as the temperature drops as in at night time the moisture can drop out of solution and become free water. ready for your bugs to flourish
 
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