Good Diesel & Bad Diesel Poll

[Jim Cate]

We've never had a dirty fuel problem (so far). However, when buying from suspect places we do use an external filter. When buying from rusty drums in the Solomons, that filter needed cleaning a few times, mid fill!

Re condensation: in many vessels, the tanks are in thermal contact with the hull and thus the water. I suspect that the thermal excursions are small in those cases. And even when the tank is sitting isolated from the sea, the temperatures below decks don't vary nearly as much as those outside in most cases. I've never worried about this source of contamination.

(Sure hope saying all this hasn't jinxed us!).

Jim

[nes]

Bought our boat in 2008, it had about 300 hours on the engine. We used it quite a bit, and the fuel filter finally clogged in about 2009, with about 400 hours on the engine. We changed both filters and got about another 500 hours before they clogged again (in 2013). So really I can't say that it was bad fuel, more like I should have changed them sooner as a precaution. Once the filters were changed no other problems, so it is not like it was bad fuel that was continually clogging the filters.

[SailRedemption]

When people say they "pre filter" going in the tank.. How does one do this? Is there a filtering funnel you use? I am just imagining a fuel hose nozzle and some kind of racor or spin on filter, and another thought of something like a tube with tee shirt type filtering haha! Never once seen this, but we always had clean fuel at our marina..

- Ronnie...on the geaux

[rwidman]

Originally Posted by Seaworthy Lass

....... A few of our tips:
- We always look at a sample of fuel in a glass jar before filling
- We fill with a filter
......

I hope I never get behind you at the fuel dock!

[Wotname]

Originally Posted by capngeo

...........
The second time, in my sail boat, I forgot the additive, and stored the boat for a 6 month period. The fuel was BLACK with algae when I got back, and clogged filters in 5 minutes. After exhausting my on-board supply of filters, I got towed back to the dock bu TowBoat/US and cleaned the tank.

Wow, that was quick, presumably due to the tank condition; I've often stored diesel for 12 months without issue but the tank was clean; nevertheless this gives me pause for thought.

Originally Posted by ytquest

I have had maybe 3 problems with fuel, but they all stemmed from not using Stabil when not using the engine for long periods or taking on fuel for extended time. I hold 200 gal's. and the solar panels have work great for the last 22 years. Air leaks in the fuel system has been my biggest problem.

What in your opinion is an extended time?

Originally Posted by roygee

Sounds like good government figures to me. Try to glass in a hole in a tank when the clouds are drifting over; you will find that the tank breathes all the time.

Welcome aboard Royee and thanks for making your first post in my poll

Originally Posted by Cheechako

How often have you experienced significant bad fuel problems?
Does this include taking preventive measures? What if I have the tank cleaned and fuel polished when ever I buy a boat with old fuel or an unknown past? Was that a bad fuel issue?

Hmm.. not sure. I suppose if you take preventive measures that prevent your fuel from going "bad", then you you haven't got "bad" fuel but if the fuel has gone "bad" and you do stuff to stop it reaching the first filter then you have experienced "bad" fuel even though it hasn't affected your engine performance. If that sentence makes sense

Originally Posted by nes

Bought our boat in 2008, it had about 300 hours on the engine. We used it quite a bit, and the fuel filter finally clogged in about 2009, with about 400 hours on the engine. We changed both filters and got about another 500 hours before they clogged again (in 2013). So really I can't say that it was bad fuel, more like I should have changed them sooner as a precaution. Once the filters were changed no other problems, so it is not like it was bad fuel that was continually clogging the filters.

Hmm... I would have thought that your fuel was suspect if they clogged in 400 or 500 hours. Clearly your experience suggests if you change filters regularly, your engine will keep running but I wonder if it is possible that this practice will mask developing fuel tank issues. A case of dammed if you do and dammed if you don't. Again good food for thought.



Thanks to all who have voted and keep 'em coming .

[Cheechako]

Hmm.. not sure. I suppose if you take preventive measures that prevent your fuel from going "bad", then you you haven't got "bad" fuel but if the fuel has gone "bad" and you do stuff to stop it reaching the first filter then you have experienced "bad" fuel even though it hasn't affected your engine performance. If that sentence makes sense

Yeah.... I had a hidden agenda there.......I'm thinking there is no bad diesel, just lax maintenance. I bought a boat that had ben sitting with non full fuel tanks for at least 3.5 years... I filtered the fuel and used it!

[ytquest]

Wotname. The first time it sat for 8 mo's. I was very new to living aboard and did not treat the fuel. We started to have algae problems (black in the racor) but they were minor. the second time my wife moved back to TN. with cancer to be with family and stay at our home! 1/2 years. lot's of algae. I used a large dose of stabil and 2 filters later and a long run to empty the tanks. We didn't have any more problems. Until the trip back to TN. after letting the boat sit another year and a half to keep it safe from divorce courts (wife found the one that got away) and that covers 24 1/2 years of fuel consumption
Oh by the way I could not get back to the boat for my normal fuel maintenance and had friends and co-workers looking after it.

[Wotname]

Originally Posted by Cheechako

Hmm.. not sure. I suppose if you take preventive measures that prevent your fuel from going "bad", then you you haven't got "bad" fuel but if the fuel has gone "bad" and you do stuff to stop it reaching the first filter then you have experienced "bad" fuel even though it hasn't affected your engine performance. If that sentence makes sense

Yeah.... I had a hidden agenda there.......I'm thinking there is no bad diesel, just lax maintenance. I bought a boat that had ben sitting with non full fuel tanks for at least 3.5 years... I filtered the fuel and used it!

Originally Posted by ytquest

Wotname. The first time it sat for 8 mo's. I was very new to living aboard and did not treat the fuel. We started to have algae problems (black in the racor) but they were minor. the second time my wife moved back to TN. with cancer to be with family and stay at our home! 1/2 years. lot's of algae. I used a large dose of stabil and 2 filters later and a long run to empty the tanks. We didn't have any more problems. Until the trip back to TN. after letting the boat sit another year and a half to keep it safe from divorce courts (wife found the one that got away) and that covers 24 1/2 years of fuel consumption
Oh by the way I could not get back to the boat for my normal fuel maintenance and had friends and co-workers looking after it.

Thanks for the explanation / feedback; trust your life is now sailing with more balance.

[Wotname]

Well anyone who is going to vote, probably has by now although please feel free to vote if you haven't done so

Let's look at the results and I have to say I'm pleasantly surprised to see that significant problems (IMO) are a minority. Certainly lower than what I was suspecting after reading so much about fuel issues, twin filters and vacuum gauges etc on CF. Maybe a case of "bad news" travels fastest.

I also pleased to see 58+% have never had a "bad fuel" problem.

I think Cheechako sums it up best with his "I'm thinking there is no bad diesel, just lax maintenance" comment.

It would also seem that the diesel condition itself is only part of the issue. Putting clean diesel (with additives) into an empty but contaminated tank will result in possible problems if (when?) the contamination falls away from the internal tank walls and enters the fuel lines & filters etc. Your thoughts please?

I am convinced that being able to regularly drain and inspect the contents of the tank sump is a really desirable way of staying ahead of the potential contamination; looking at the water separator in your fuel lines or filter is a very distant second line of defence. Almost a case of shutting the door after the horse has bolted. I understand that having a fuel cock on the drain point is frowned on (or perhaps disallowed) in some areas but I consider the benefits to outweigh the potential risks. Maybe this is just an old aviation habit of mine where the tanks are checked for water each flying day. It's waaay too late once the water has entered the fuel pickup / line .
Again, your thoughts?

Thanks to all who voted

[Jim Cate]

No bad diesel??? HAH!

As mentioned above, try buying fuel in the Solomons, where a previously rusty drum was delivered to the village a year ago where it was then left out in the rain with the cap not down tight until the day you, in desperation, bought some of it! Obviously, prefiltering helps in such cases, but surely, this is BAD diesel!

And thinking back, at the marina in Whangaparoa, NZ, back in the early 90's, the fuel dock was across the entrance channel from the marina proper where the storage tanks lived. There was a pipe that ran under the channel to the bowser, and sure enough, in time it leaked, and a poor chap with a biggish m/v filled up with a mixture of diesel and sea water. Big problem... and again, BAD diesel IMO.

But fortunately, these are infrequent problems for most yotties, and cruddy tanks are a more likely source of difficulty IMO.

Cheers,

Jim

[leftbrainstuff]

I always look for fresh diesel and I always prefilter when filling my tanks. This is a typical preventative maintenance practice. I also polish my diesel on a regular basis. Again this is preventative as I can see any contamination or water buildup issues in my Racors. I can always state with high confidence the condition of my fuel. This helps me sleep at night.

If you just rely on luck then you may be lucky for years. If you ever do have an issue then you'll have a corrective maintenance issue to deal with. You don't get to pick when and where you will have to do corrective maintenance. With preventative maintenance you get to choose when and where. This is the basis of all professional maintenance programs.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[leftbrainstuff]

Originally Posted by Wotname

Well anyone who is going to vote, probably has by now although please feel free to vote if you haven't done so

Let's look at the results and I have to say I'm pleasantly surprised to see that significant problems (IMO) are a minority. Certainly lower than what I was suspecting after reading so much about fuel issues, twin filters and vacuum gauges etc on CF. Maybe a case of "bad news" travels fastest.

I also pleased to see 58+% have never had a "bad fuel" problem.

I think Cheechako sums it up best with his "I'm thinking there is no bad diesel, just lax maintenance" comment.

It would also seem that the diesel condition itself is only part of the issue. Putting clean diesel (with additives) into an empty but contaminated tank will result in possible problems if (when?) the contamination falls away from the internal tank walls and enters the fuel lines & filters etc. Your thoughts please?

I am convinced that being able to regularly drain and inspect the contents of the tank sump is a really desirable way of staying ahead of the potential contamination; looking at the water separator in your fuel lines or filter is a very distant second line of defence. Almost a case of shutting the door after the horse has bolted. I understand that having a fuel cock on the drain point is frowned on (or perhaps disallowed) in some areas but I consider the benefits to outweigh the potential risks. Maybe this is just an old aviation habit of mine where the tanks are checked for water each flying day. It's waaay too late once the water has entered the fuel pickup / line .
Again, your thoughts?

Thanks to all who voted

Good objective summary. Nice one.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Seaworthy Lass]

Originally Posted by Wotname

I also pleased to see 58+% have never had a "bad fuel" problem.

I view this figure quite differently .
A whopping 42% of people voting have had problems, and almost a third of those "More than twice and to the extent the engine won't run and/or needed multiple filter changes."

Given how vital an engine can be in an emergency and given how vital clean fuel is to an engine running, these figures indicate bad fuel (which is most likely poor maintenance) is a huge concern.

Originally Posted by Wotname

It would also seem that the diesel condition itself is only part of the issue. Putting clean diesel (with additives) into an empty but contaminated tank will result in possible problems if (when?) the contamination falls away from the internal tank walls and enters the fuel lines & filters etc. Your thoughts please?

We saw this happen first hand. A near empty contaminated tank was filled on a private yacht just before exiting a marina. Within a couple of hundred metres of leaving the entrance the engine failed. Rough seas were a contributing factor in stirring everything up. The boat was just about on the rocks when a tow line was secured.

The yacht was towed over to our anchorage, as conditions were too rough to enter the marina, so we went over to give them a hand. The fuel filter was clogged with black stringy slime. The engine would still not run with a new filter. Cutting the fuel line showed it was packed solid with this slime. A new filter, and fuel line to a jerry can fixed the problem temporarily.

The owner was concerned about getting his tank clean - there was no decent access. One other thing to check when boat hunting.

Having witnessed all this, I now take a keen interest in fuel and tank cleanliness .

Originally Posted by Wotname

I am convinced that being able to regularly drain and inspect the contents of the tank sump is a really desirable way of staying ahead of the potential contamination; looking at the water separator in your fuel lines or filter is a very distant second line of defence. Almost a case of shutting the door after the horse has bolted. I understand that having a fuel cock on the drain point is frowned on (or perhaps disallowed) in some areas but I consider the benefits to outweigh the potential risks. Maybe this is just an old aviation habit of mine where the tanks are checked for water each flying day. It's waaay too late once the water has entered the fuel pickup / line .
Again, your thoughts?

Having a pickup from the very bottom of the tank for testing essentially serves the same purpose. If polishing fuel, this is then the pickup that is used. Our tank has three pick ups and associated Raycor filters - the sump and one each for the main engine and generator. These can be interchanged providing redundancy in the system. It also means a filter can be changed if necessary without stopping the engine.

[SailRedemption]

I'll ask again as I think it was overlooked, how are you guys "pre-filtering" your fuel? I have never seen this done....

- Ronnie...on the geaux

[Seaworthy Lass]

Originally Posted by SailRedemption

I'll ask again as I think it was overlooked, how are you guys "pre-filtering" your fuel? I have never seen this done....

We use a funnel similar to the one below. It is designed to trap water as well as particles, although with the rate the fuel is swirling around it seems unlikely it would do a good job at separating water. A better way to avoid water is to take a sample of the fuel in a glass jar first, let it sit then check carefully for water.

The funnel is a good first line of defence against particles and the appearance of bits also alerts you while filling if you should stop and buy elsewhere.