Sailboat Diesel Fuel Cleaning/Debugging for Cruising Sailors

The adage "Give your diesel engine clean fuel and it will run forever" is very true.

The RNLI, Sea Tow, USCG and many organizations will tell you that the most calls they get for assistance start by being engine related. They will also tell you that 90% of engine failures are due to Fuel issues. Bad Fuel is not a inconvenience issue its a safety issue.

What causes diesel fuel problems on a sailboat? 

The two biggest ways to ruin a tank of fuel, either a diesel or gasoline powered yacht, are water contamination and long-term storage.

Water can get into Fuel in so many ways. Even if you get dry clean fuel, your tank system is vented (unlike a car) and the vent will let in humidity. Water also condenses on the tank walls due to temperature fluctuations, especially true in winter. The more air in the tank the more condensation. Its recommended that you keep your tanks up to 95% full to combat this.

Fuel sits on top of any water that will eventually settle to the bottom. Bugs can thrive in this water. You can kill these bugs with BIOCIDE? but you will still be left with their carcasses, which when disturbed in rough water can get to your filters. No water in the fuel no bugs or algae

Fuel clogging can be a problem. It always seems to happen at the worst time. You are in rough water and the motion stirs up the sediment in the tank and the filter gets clogged. You need to shut down the engine but you are in a nasty channel and need the engine.

Filling with the wrong Fuel. Gasoline in a Diesel Fuel system is disastrous and could involve the risk of explosion, so make sure the fillers say Diesel only.

What can you do to keep your Diesel clean

Clean Fuel tanks

Filter fuel as it comes aboard

Keep Water OUT

Stabilize Fuel that's stored or sits idle

Biocides kill bugs

Dispersants separate water from Fuel

Filter fuel before it gets to engine

Polishing Fuel systems onboard

My major hiccup with diesel was shortly after purchasing my boat and whilst fitting her out for cruising. I had not taken her to sea at that time and was still familiarising myself with her. 

One balmy evening on dusk I decided to top up the water tanks (you know already what is coming?). On the port side there were two filler caps, one marked for water and the other for diesel, the starboard filler for water only. The filler for water was covered by the spinnaker pole and in the gloaming I unscrewed the diesel cap in error and proceeded to fill that tank - with water!! Half way back down the companionway something triggered in my mind and I leaped back out to check, already with that terrible sinking feeling in my stomach convinced of my mistake - sure enough water was bubbling merrily into the port side diesel tank - too late, as several gallons had passed in already! 

Most of the next day was taken up by pumping out with a hand pump the total contents of that tank into 25ltr jugs - fortunately it was only around half full - but imagine the horror if I had left the water running and it had overflowed onto the deck and worse, into the marina? Doesn't bear thinking about!

As I was fitting out the boat over a period of months I wasn't in any hurry, so once the tank was drained and left to dry for a few weeks it was safe to refill with diesel fuel. I did however, have the local diesel mechanic inspect it before refilling. 

This is the kind of mistake you DO NOT wish to commit when you are in foreign parts/ports.



De-Bug L140

As my ultimate goal was to sail from the UK to New Zealand, I started to think about keeping the diesel clean because we would no doubt have to take on diesel in places where the fuel could be suspect, dirty or with contamination - we have all heard stories of this happening with potentially disastrous results.
I wanted something extra, over and above good filtration to keep the fuel in the tanks bug free. I came across the De-Bug product (Miami Boat Show) and whilst it seemed a little out from left field, it also appeared logical so I thought I would give it a try. For around $200 for the 48 horses of the Perkins 4108 the L140 seemed good value so long as it worked.

I fitted it into the fuel lines along with an additional Racor filter and replaced the floorboards. We sailed ten thousand nautical miles after that and never had any problems. The engine was only ever used to get into and out of port or in emergencies or to motor for a few hours in a calm, so there was plenty of time for bug type growths to occur if they were going to.

The peace of mind brought about from clean fuel and knowing your engine is always going to start when passagemaking in far seas, is priceless. 

The following is the technical data from the De-Bug company website
www.dieselsolutions.co.nz :     

It takes more than a magnet to make a De-Bug. Only genuine De-Bug units have the exclusive TRI-MAG™ and MULTI-MAG™ Bug Killer Packs.

Technology using magnetic flux fields to combat microorganisms and their associated problems in aqueous fluids has been developed in New Zealand. The theory that magnetic flux fields inhibit microorganism growth and survival has long been noticed and has now been proven.

Over the years, many have tried to develop a device that was effective on all flow rates with limited success. Lindsay Forrest is hailed as being the inventor of DE-BUG Clean Fuel Units. While designing the DE-BUG™ unit Lindsay became aware that a single magnet device could not produce the desired efficiency, and that an oscillating field was the most effective because microorganism cells could not react quickly enough to a rapidly changing magnetic field.



An oscillating magnetic flux field effect could be simulated by carefully directing contaminated fuel flow through a stack of multiple permanent magnets. By directing microorganisms into and out of the flux field at a predetermined flow, a simulated oscillating field was achieved. Shortly after, the De-Bug™ Model L-1000 Fuel Decontamination Unit was launched which fully incorporated this concept. The success of this unit is based on a specific flow rate through a stack of three ferrite-metal ceramic-coated permanent magnets known as the “TRI-MAG Bug Killer Pak™”, which achieves a microorganism kill rate efficiency of nearly 100% (97.6%) in one pass. These permanent magnets have a service life of 20-50+ years.

Housed within the De-Bug Fuel Decontamination Unit, the “TRI-MAG™ Pack consists of three flat donut shaped permanent magnets, manufactured from ferrite-metal and ceramic-coated, stacked each above the other. The spacing between the magnets is scientifically determined in order to produce the optimum flux field density. The magnets are arranged and held in place with special spacers in such a way that a north pole always faces a south pole. These spacers are manufactured from Acetyl M90 plastic. As with all other special engineering materials used in the De-Bug, this material is used for its resistance to diesel fuel and similar hydrocarbon based products. In addition, Acetyl M90 plastic is used for its adaptability to cope with various applications such as the harsh marine environment, the mining industry, and agricultural equipment. Acetyl M90 Plastic is also particularly resistant to environmental stress cracking and numerous chemicals usually associated with diesel fuels. Further, it is capable of withstanding extreme temperatures.

Within the De-Bug unit, the spacers perform two functions. First, to create and maintain proper distance between the magnets. Second, to direct fuel flow through the magnetic flux field. As the fuel passes through the De-Bug, any microorganisms are subject to a rapid magnetic field change four separate times or four oscillations. This unique patented design (US patents 5,248,437 and 5,055,188, New Zealand patent 231876), exclusive to De-Bug products, is what enables De-Bug Products to achieve their unparalleled effectiveness and success. De-Bug holds exclusively, the patent for all multiple magnet device designs, which are incorporated in every De-Bug Product. If it does not have a TRI-MAG™ or MULTI-MAG™ Pack, then it is not a DE-BUG™.

Maximising Magnetic Flux Density to Effectively Kill Cells

Magnets are polarized charged particles that radiate magnetic flux. Flux lines always start at the North Pole and seek a South Pole that is normally at the other end of the magnet. The flux lines radiate out in an elliptical manner.



De-Bug Magnet Structure

The unique make-up of the magnetic field in the De-Bug fuel treatment unit is made possible by stacking three annular shaped permanent magnets on top of each other to form the patented “Tri-Mag” stack. A number of Tri-Mag stacks placed in line make up the patented “Multi-Mag” stack that is used to provide more powerful units.

The magnets are stacked to ensure that the North Pole of one magnet always faces the South Pole of the adjacent magnet. This results in the magnets attracting at all times and therefore maximises the flux density, and the resulting destructive effect on microbial cells, in the spaces through which the fuel and microbes flow.

When the fuel and microbes flow between the magnets and through the centre of the middle magnet in the Tri-Mag™ pack, the flow path causes the microbial cells to experience the maximum levels of magnetic flux density from several different angles, and 24 changes in polarity of the magnetic field.

This overwhelming attack from all directions, combined with the oscillating field strength can eliminate microbial contamination when used in a fuel system where fuel is re-circulated through the De-Bug unit either on a periodic or continuous basis.

De-Bug Units are static magnetic inline device that create an optimum magnetic flux field directly responsible for destruction of the cell membrane. Exposing the microbes to a strong, changing magnetic field will ensure maximum destruction of the cells. The debris stays randomly suspended in the fuel and due to their sub-micron size easily pass through engine components and burn up with the fuel.

What Makes Our Product Using a Three Magnet Stack Different?

De-Bug Units are One of a Kind. The inventors (in knowing how good this system is) patented the De-Bug system worldwide. Single magnet systems are sub-par to the De-Bug System.

In the development stage the inventors of De-Bug Units used single magnets Units and found them to be partially effective. That could be Ok, as there was nothing better on offer in the market, however after further testing using different combinations of magnets, gauss strengths and configurations they concluded the triple & multi magnet systems were substantially better for eliminating microbial contamination than a single magnet.

De-Bug Units have proven themselves tens of thousands of times and the proof being they are authentically endorsed by significant number of end users that have had a persistent bug problem, by fitting a De-Bug Unit; the bug problem has been solved permanently!

De-Bug Units are One of a Kind. The inventors (in knowing how good this system is) have patented the De-Bug system worldwide.

Images and article courtesy De Bug NZ, video courtesy YouTube

You can read much more about diesel fuel, filling techniques and other incidents whilst cruising, in my ebook 'Sailing Adventures in Paradise' downloadable from my website www.sailboat2adventure.com