Christopher’s WMO System
Our first WMO filtration setup was outdoors due to limited space inside of the garage. This was accomplished by setting a 275 gallon tote on top of another and positioning the WVO Designs centrifuge on top of a 55 gallon barrel so the top tote would be the dirty “settling” tank and the bottom tote the clean tank. The 55 gallon barrel was for draining the sludge into and also there in case the power shut off unexpectedly and the oil was draining straight to the barrel instead of into the clean tote.
After moving, I had space inside a garage to setup a more efficient cleaning system. I didn’t want it to take up as much space, and found that having over 500 gallons of capacity wasn’t needed in my case. We decided on using 2 55 gallon barrels in place of the 275 gallon totes. This would allow me to keep my footprint smaller in the limited real estate of a garage. I also decided I wanted a secondary containment that would hold over 60 gallons in case something sprung a leak in order to give me more peace of mind. Following is an explanation of what we ended up designing and implementing for collecting, settling, filtering, and delivery as well as some of the reasoning for each step.
The first step, of course, of filtering oil for use in my vehicle is the collection of said oil. We have a 55 Gallon barrel that I put in my 1993 GMC 6.5l Turbo Diesel. On top of this barrel is a pump that we made from the oil pump for a small block chevy modified with inlet and output for hoses and a 24v electric scooter motor with its shaft ground down to fit into the oil pump. The pump works on the 12v system of my truck pretty well and will put a vacuum on the pickup hose allowing it to run without being primed first since this is a positive displacement pump. For hose, I used a pretty inexpensive option by pickup up suction hose from Northern Tool (Item# 507510, PVC Suction Hose 1in. X 20 feet). This appears to be the same material used for flexible electrical conduit which might be an even less expensive option if you can find good ends for it. The plastic ends on this hose have been slightly problematic when pushing oil back out the hose, because of course when in suction oil is less likely to make its way out.
On the hose from the pump to the PVC pickup stick we used Washing machine hose from the local hardware store as the material is rated for oil. It has held up for a couple of years now with no issues, the Suction hose has gotten stiff over the years but is still holding up pretty well.
I discovered those collecting rain from their gutters were also looking for ways to stack 55 gallon barrels and found a design for stacking a couple of barrels. I modified it by putting more space between the barrels to allow for the drop to the Centrifuge and from the Centrifuge to the clean barrel without losing oil storage capacity.
The containment area is about 3’X5’ with 10” sides made out of 2”X10” boards. The liner is shower pan liner from the local hardware store. It’s very thick rubber and I simply stapled it in.
We added ¼” drain holes to the bottom of both clean and dirty tanks for taking any water off as needed. I have found that pumping dirty oil into the top tank and letting it sit a week does a lot of the cleaning for me without having to empty the centrifuge bowl so much. Most of the water drains off during this 1 week waiting period. I can then typically run hundreds of gallons through the centrifuge between cleaning out sludge and water. Of course this depends on the cleanliness of the oil you are collecting.
The in-line heater is made from standard plumbing parts and fits a standard electric water heater element. We have a drain valve at the bottom of the inline heater which is opened momentarily before starting a cleaning cycle just to make sure there isn’t any water sitting at the lowest point in the system. The gate valve is used for controlling flow rate into the centrifuge. It gives me a little more precise control over the other valves in the system.
We got fed up with cleaning out the Centrifuge pretty quickly and “plumbed” an old Rainbow vacuum cleaner into a 5 gallon bucket and then ran a hose from the bucket to use for sucking out sludge from the inside of the centrifuge, essentially creating a shop vac on the cheap since I had it lying around. This proves to be faster and less messy than getting in there with a spatula or other tool to clean out the sludge and throw it in a bucket.
Once in the clean barrel we, of course, needed a way to pump into a vehicle. Since we didn’t need a self priming pump we went with a centrifugal which also allows us to have a cutoff valve at the end of the hose without worrying about the hose bursting from a positive displacement pump. We went with this Harbor Freight pump which pumps oil at about 5GPM quite reliably. (Item# 69297, 3/4 Horsepower clear water pump). I have an auto-cutoff nozzle at the end but it doesn’t work. I’m not sure if this is due to the viscosity of the oil, low pressure coming from the pump, broken nozzle, or some combination of the above.
To make things a bit more “put together” we permanently wired up the In-line heater, Centrifuge, Vacuum, and Clean Pump with home light switches. We also wired it so that the In-line heater will not turn on until the Centrifuge is on, for safety. While it likely wouldn’t be an issue if the heater was left on, I felt safer with it this way.
This setup has worked really well for us. I feel like it has the safety features I need with the fire extinguisher readily available, secondary containment, in-line heater cutout, etc. If I were to design this again I would want to minimize the distance from the in-line heater to centrifuge hose to keep heat from being lost in transit. Also the nozzle for filling up my vehicle would likely be better as a simple on/off instead of an automatic as it is finicky getting it to stay open for oil to flow. The total cost for this setup, including the WVO Designs Centrifuge, I estimate to be around 2000.