29 comments on “How To Make Black Diesel

  1. Hello,
    I’m looking to make a machine with Centrifuges is there a blue print you could show me or something similar?


    • Hi Mike,

      Sorry I didn’t get back to you right away. I could work on a blue print or a video for you that would detail the process a little better for you. However, most set-ups are pretty custom to an individual’s needs and will require some building skills. It’s nothing you probably can’t handle, though. Is there anything in particular that you have a question about?

  2. Hi and thanks for the informative write up. I am also working on my filtration setup and will be purchasing an extreme raw power centrifuge. I have a raised WMO storage container with a177 micron lid filter similar to yours. Do you think I will be OK with just a gravity fed setup to the centrifuge? I would like my setup to be really simple and I’m trying to avoid the pre-filter setup going to the centrifuge like in your setup. Your input will be appreciated.

    • Hi E,

      I would say that since you are using a centrifuge (especially the type you chose) you should be fine with a basic pre-filter setup and gravity feeding it. Since I started making WMO, I’ve filtered quite a bit of oil and have noticed that my filtration setup could be minimized to the bucket filter and maybe the goldenrod water separator before the centrifuge. It would provide the same results. I just want to point out that even when I filter down to 2 micron with filters, I still clean a lot with the centrifuge!

      I hope this helps. Please feel free to ask more questions!

  3. Congratulations for your contribution to reduce the oil contamination to the environment. Could you please send me more detailed pictures of the installation of equipments or a diagram?

    • Jose,

      I could definitely work on some pictures and diagrams for you. Is there any part of the process you specifically have a question about or need to see in better detail?

      • Nick:
        I would like to know if your are using the same barrel as polishing and finishing barrel, and using only one pump to filter and to centrifugate de WMO.


        • Jose,
          I am using 2 barrels and one pump. My first barrel is a holding barrel and the second one is for polishing. The pump sucks the oil from my first barrel, through a set of filters, and pushes it through the centrifuge into my polishing barrel. Once all the oil is in the polishing barrel, I can manage my valves on the system so the pump draws only from the polishing barrel to circulate the oil through the centrifuge. This is also the same barrel I blend in.

  4. Awhile ago I emailed you about my glow plugs burning out. I talked to some mechanics and they said that the heat produced from burning 100% black diesel would melt my plugs. Not sure if that’s true or not but I went through 3 sets of plugs, all melted,running only wmo blend at 15& RUG. I’m now running a blend between D2 and WMO, figured 70% D2 and 30% wmo would make a good winter blend. Do you know if there is a glow plug for a 6.2 Detroit diesel that would handle 100& wmo blend.

    • I never received a message about your glow plugs burning out, it must have gotten lost. However, it is my understanding that glow plugs will burn out if your timing is too far retarded or advanced. Your truck should use a Stanadyne DB2 injector pump (I think), so you will need a special timing device to set it. It uses in impulse measured from the #1 injector hard line and you have to rotate the head of the pump (toward pass. side is advanced). Are your glow plugs literally melting? If so, what are your exhaust gas temperatures? You really should get an EGT gauge (pyrometer) if you don’t have one. They give you an idea of what is happening. I think you are on track for a good winter blend, as I have been considering 50% D2 and 50% W85 for winter.

      I really don’t have much experience with GM diesels, but I could do some research for you to figure out which plugs will work best. I know with the Ford diesels, BERU are the only recommended brand, but GM’s may be different. check your timing and let me know what you get.

  5. Not a problem. Yeah the tips are completely melted off. Not sure how to upload a photo to show you. I have a EGT gauge and did notice that the engine runs a little cooler with almost 100% D2. I will look into the timing though. So far I’ve burned out 2 sets of Autolite plugs and 1 set of AC Delco’s. From the research I did they said the Delco’s are the best plug but not sure with wmo.

  6. hi, it is great but you didn’t show the picture on how it is centrifuged. Pls explain how open bowl centrifuge works.

    • Esteban,

      I apologize for missing your comment. I do not use an open bowl style centrifuge in my setup, although I’d like to have one. They work similar to the pressure driven style, but they are run with a motor instead of the pressure from the oil. Typically the oil is fed into the centrifuge at a much slower rate also. These types can exert a much higher centrifugal force on the oil, pulling much more contaminants out.

      Here’s a video from Simple Centrifuge: https://www.dropbox.com/s/m3kcvnovfv1cmah/how_it_works.wmv?dl=0

      Hope this helps.

  7. Hi, I have been interested in black diesel for a while because I have farm machinery and a local mechanic works out of one of my barns and always has WMO to dispose of. I made my first mix and followed the instructions, I don’t have a centrifuge but passed (poured) it through many filters down to 5 microns. I say ‘poured’ because I mixed the RUG before filtering thinking it would flow better after the viscosity had been reduced.

    I half filled the tank of my 20 year old mini tractor and off I went. After about 15 – 20 mins the motor started to lose power and run rough, I figured this was when my black diesel reached the engine! Thankfully I managed to struggle back to the yard but there were times when I wasn’t sure there would be enough power even for that.

    I’m now awaiting a 1 micron filter bag, maybe overkill to some but I want to eliminate contaminates as much as possible. I aim to check the engine filter for buildup again to eliminate contaminates and finally drain the fuel and refill with pucker diesel just so establish it is the black diesel and not a coincidental engine fault.

    The way I see it the inexactness of the viscosity of modern oils means no hard and fast rule will apply to all … they start with a different viscosity, then vary with temperature and from my experience can lose viscosity if flogged to death in the original engine (how many farmers service there 20 year old or more tractors to manufacturer service intervals?!). 🙂

    Anyway my question is … assuming I have a wrong mix. How do I know if it’s too thin or too thick? That it passed straight through a 5 micron filter does that suggest it’s too thin and could benefit from thickening up?

    David Caple

    • Hi David,

      Let me start by asking how much RUG you used in comparison to WMO. I recommend around 10-15%, but it really may depend on your engine. I’m going to use 5 gallons as an example, but use liters as it applies to you. So if I wanted to mix a 5 gallon bucket of WMO into W85 (85% wmo/15% RUG), I would blend in .75 gallons (3/4 gallons) of RUG. I find keeping your numbers more specific aids in keeping your records straight so you can figure out what works best.

      As for blending, I usually filter before blending, but it can go both ways. Truthfully, it does not matter when you blend, but in your case it would probably make things easier to blend before.

      One thing that I have noticed and experimented with when it comes to WMO is sludge removal. Sludge will kill your injectors faster than anything. Bag filters are not very good for removing sludge, which is why I strongly recommend a centrifuge. I am not saying it can’t be done without one, just stating that your experience may not be as pleasant.

      When it comes to WMO, not all waste oils are created equal. I have had good luck with waste engine oils from heavy machinery, Automatic transmission fluids, hydraulic oils, transformer mineral oil (my favorite), and cutting oils. However, oils from gearboxes are typically too thick for fuel purposes and do not work well. Also, be cautious of water. Water in your oil can wreak havoc on your system. I’ve heard of numerous ways of removing water from heating and settling (this takes months) and Goldenrod filters to water absorbent beads. I’ve always wanted to try the beads, but haven’t gotten around to it yet. They can be found on eBay and are typically advertised for decorative purposes in vases and such. they might be a great option for you. Most people put then in pantyhose and let them soak in the oil for a period of time. Again, a centrifuge will also help remove water.

      Another note on WMO is that it can make existing issues in your engine exaggerated. If things were already bad, they can get worse quickly. I might suggest cleaning your injectors and running your engine hard, some call this an “Italian Tune-up”. It works well. As the engine is 20 years old, you would have an IDI engine and the pre-cups may be coked (carbon buildup). Coking would need to be removed manually, but the tune-up can help. I’m not sure what the UK has for Diesel Injector cleaner, but you should run a dose of the maximum amount in your tuneup.

      You may also want to verify you don’t have bad injectors or an air intrusion. If you stay away from the crud on the bottom of the oil, that should help as well. The 1 micron filter is not overkill.

      Keep me updated and I wish you luck.

  8. Is there an easy way to check the viscosity of your finished fuel to know if you have added enough RUG? I would think a hydrometer, but wasn’t sure. Thanks

    • Jacob, I missed your question and I assume I am too late for your answer. I apologize. I have read about people using a hydrometer, but there are other ways as well. If you were to make a hole in a cup and time how long it takes for a volume of diesel to empty from the cup and do the same with WMO, you would know that when the WMO time matches the diesel, they should be close. Be careful not to add too much RUG.

  9. Hi, tanx for the great info. I want to start a small project and this will help alot. I live in Africa and unfortunate I could not say if our gasoline is unleaded or not. Will it give problems if leaded for RUG? I want to use it on a Lister machine to pump water.

    • Anthony, I did a quick search and found that as of current, Algeria still used leaded gasoline to some extent. That is not to say that it is not still out there. I have no idea if this would have any affect on WMO for use in a diesel engine, but I would use unleaded if at all possible. In a lister machine, I would assume it would be ok in modest quantities, but in a vehicle I might remain cautious.

  10. Nick (in response to Jacob) … sounds like a good idea but you would need an in-line tap or end plug so you don’t start the flow until ready to time it. I found a tubed container in my scrap where a table tennis ball was a close fit. Yes it floated so I made a small hole and filled it with a setting resin. Now I drop the table tennis ball in the tube filled with oil and time how long it takes to fall. Both systems would work but … Don’t time the event with real diesel and always work to that time because viscosity varies with temperature. I keep a small amount of commercial diesel to hand so when mixing a new batch I re-time the commercial viscosity and work to that. Here in the UK there is a significant variation in time between summer and winter.

  11. Have any readers come across this problem? I am testing the fuel in a rough ground mower before fully replacing commercial diesel. I filtered my Black Diesel through 200, 100 and 50 micron bucket filters and then 25, 10 and 5 micron sock filters (all sizes as claimed by the filter supplier) but I kept getting fuel filter blockages. On draining the tank I found small black pieces of debris. They tended to be flattish and about the size of a small grain of rice or smaller but should definitely have not got through even the 200 filter let alone the 5 micron one! I put that down to general debris that can accumulate in any tank over the years but when I kept getting the blockages and finding the black pieces even after fully washing the tank I started to wonder! I am using spent engine oil often taken from road going diesel cars/van donated by a mobile mechanic friend who services customer cars at their home or place of work. He has suggested that because the oil often comes from diesel engines it could have a high carbon content that can pass through the filters but when left standing in the tank will settle on the bottom of the tank and stick together until stirred up when the vehicle is used. To test this I’m thinking of putting a spur into the fuel line so that I can drain the tank every time I put the mower away and then refill the tank the next time I want to use it but before doing so I just thought I would see if anyone else has come across this problem. Does the mechanic’s theory sound like a reasonable cause of my problem? If so will using a centrifuge be the best solution?

  12. Hello
    In m’y WMO recycling système , i use distillation and 2 microns filter with a pump.
    After distillation a-t-il 400degres , the viscosity became 80% similare to normal diesel and with dynamic filtration , the color tend to normal after this process, we just need to blend IT with 20% gazoline and IT is ok.
    I HOPE IT CAN help

    • That is pretty cool! I wanted to try distilling some diesel, but decided it wasn’t for me. I can’t do that type of stuff in my neighborhood.

  13. Hello, I’m only going to be using SAE10 hydraulic oil. I get about 120 gallons monthly so that will be soul source of oil. I was wondering if the filtration process is still just as intensive As WMO?

    • Mike,

      It really depends on the oil WMO has loads of contaminates in it. I sometimes use mineral oil and just run it through a single 15 micron fuel filter. If it has sludge and/or metal particulates, filter and centrifuge. If it is still clear or amber, you can probably just filter. If it’s black, just make sure it doesn’t have sludge or metal particles. If it does, you won’t like the damage to your pump and injectors.

  14. Hi I can’t find any information on mixing rug safely with WMO I have 1200 litre stainless tank with a pneumatic stick mixer 20petcent rug is a large amount I am worried about static igniting it also what about vigorously mixing in sealed tank will this cause tank to expand thx

    • Adding grounds to everything should beat the static (tank, mixer, lid, etc). Make them all to a common ground. Also, it shouldn’t be a closed system, it should be ventilated. I would add breather to the lid. In addition, I would ventilate the room as well.

      Side note, the site got hacked, so I apologize the late reply. I just got my access back.

Leave a Reply

Your email address will not be published. Required fields are marked *