I need to make a very fine oil filter

I need to craft extremely fine oil filtration. I will be pouring batches of hot oil through this filter at about 5 gallons at a time. I am using a huge collander as the catch basin, and so will make the filter fit it. Oddly enough, the filter will look a lot like a huge brassiere cup in shape.

In an attempt to achieve this goal, I bought polyfiber in rolls. I layered it x4 and clamped it to the collander edges. And, I poured. The layers caught most everything. what I am left with, when examining this used cooking oil, is translucent oil with a hazy cloud of particulate suspended in it. When I leave the sample jar to sit for a few days, a lot of the particulate has settled to the bottom- but the cloud remains.

I have to craft a filter that filters to 10 microns. One is commercially available, but is made in the shape of a tube sock and is impractical for my applications.

Does anyone know what combination of polyfiber or other cloths can be sewn together to make a filter that will work to this fine a measure? 10 microns will yield oil that you can see through, it’s so cleanly filtered. I use the sewing machine around these parts, so taking combinations of materials and sewing up my own huge filters is not a problem. I just need to get a handle on the right materials to use.

And, does it make any difference in terms of how well this polyfiber sheeting works, if it is sewn together tightly? I Just laid 4 panels over eachother and poured through. Is there something about having 4 layers sewn tightly together that would alter the filtering characteristics?


My initital off the cuff thoughts:

10 microns means you can’t have any seams, the tube sock thing is most likey seamless. I would imagine that making a seam impervious would be a tall order in a porous material.

Additional layers of material with the same porosity will simply make it take longer to get the same cloudy result and with more oil trapped in the fibers.

You can buy “micronic” wire mesh samples from these folks for 8 each + 3 shipping

How about using a auto oil filter. You would need to construct a container with such a outlet that would allow the oil to go through the filter.

I don’t have one with me right now but you may just need a threaded pipe to fit into it, the oil will have to flow through the filter to get out (and would just run over the filter into a catch pan).

Some transmission filters are just screens and may be able to work with.

Oh, I’ve built one already !! I used a Remote Filer mount, and standard pipe threaded stuff. Here’s the rub- I have to do coare filtering first, to remove large particulate. I wanted to avoid doing two filter runs for every batch- it wastes a lot of time. But the biggest impediment is that the automotive oil filter requires pressures. I cannot pour the oil in. I will need a battery-operated pump. This seems to be in my future with this project ANYWAY, but I was dearly hoping to avoid a double-filter run for every batch.

I currently have 100 out of 110 gallons still raw and unfiltered. The goal is to work through this batch, and then be able to quickly but carefully filter as I get the raw materials. If it is the case that I have to coarse, then fine filter, that’s ok. I’ll live. I just need a pump. Auto filters are very cheap, and can be replaced in a few seconds in the set-up I’ve built.

I just hate to waste the time to double-run the stuff. The metal mesh Micron Filters sound perfect, but are So expensive that I need to use that as a last resort.

As for the sewn seam being a leak point, I watched a fellow on a DVD I bought on the subject, pumping the oil up into a l long tube like filter that his company sews. It was clearly a long rectangle that’d been sewn along an edge to make a “tube” like shape. Metal ring on the top with a loop for hanging, tucked into a closure at the bottom that was sewn closed. Apparently in his case, the seams don’t leak enough particulate to wreck the filtering process.

The Transmission Filter idea is most excellent, and if I can pour the oil straight into that filter and know it will work, then I can lay a tranny filter BENEATH the large collander and in a single pour of 5-6 gallons, have it coarsely and finely filtered. THAT is efficient to me.

Tranny filtering. Hmmm. :slight_smile:

Will you let us know when the Death Ray is finished?

From having to filter biological samples through a 22 um filter, I can tell you that a two stage filter will result in fewer headaches. If you filter out the larger particles first, the flow rate through the second filter will be faster, possibly making the total filter time less than a single stage process. If you can come up with a centrifugal apparatus, that can be used to very quickly settle out the larger particles.


FWIW - There is a “Waste Watts” group/forum on Yahoo that has numerous posts regarding recyling vegetable oils for use in diesel and burner applications.

Not gonna work. Every tranny filter I have ever seen is just a mesh or maybe a piece of filter material. The mesh is not a very fine one at that. Think window screen. It is just there to keep dogs and small children out of the transmission. Also the square inches of a tranny filter is very small maybe 12-15 square inches. On the other hand a Volvo gas engine oil filter [useless fact that sticks in my mind] is 328 square inches[/uftsimm]
I’m not sure what size particles filter engine oil filters filter to, but an engine oil filter or a fuel filter from a fuel injected car might be your best bet.
Is this a one shot deal, or are you going to be doing this on an ongoing basis?
Thinking about this I think the best best particulary if you are going to do this more than once would be to set up a remote oil filter and then run the oil through a diesel fuel filter. Diesel fuel filters have two advantages. They are very fine, and they are huge. You might go through a couple of engine oil filters getting out the big stuff, but one fuel filter should be good to go for many, many gallons of oil.
Not super cheap to set up, but can be used over and over again.

There’s a machine specifically made for this purpose. It works very well, and it has been around for a long time. I used one at the Burger Chef where I worked in 1967. You could probably cobble together something similar. Anyway, the oil was drained from the fryer’s spigot into a basket about 18" across with a paper filter partly filled with diatomaceous earth. A pump in the base sent it back to the fryer. After a little while (10 min.?) the oil was fresh and clean again.

We kept the filter powder in a cardboard barrel in the storeroom. Right next to it was another cardboard barrel containing scouring powder. One of my co-workers, on his first time using the filter, scooped powder out of the wrong barrel. He ruined a batch of frying fat in a really dramatic fashion.

:eek: :eek: :eek: Lawdy. Did he get fired? I’ve never heard of this process but it is interesting-sounding.

The two-stage thing doesn’t break my heart, if it means I won’t wreck my car. :smiley: ( A really good goal, not wrecking my car ! )

The using of a car oil filter to remove french fries, onion rings and small children kinda bothers me. I think I’ll try using the filter material I’ve used so far, and then buying a pump with a DC source and pumping the freshly coarse-filtered stuff through the remote oil filtering pipe set I built already. I am thinking that I will yield stuff I can see through clearly. ( My little litmus test. )

Dia…wha?..earth? What Earth are you from? And, where do I get some? I can buy HUUUGE coffee maker filter meshes from a restaurant supply house, and huge coffee filters also. I could see using them, if the flow rate were acceptable. Just for yuks, I poured a bit of the sample into a coffee filter that I’d rested in a regular kitchen strainer, and sat over a measuring cup.

One drop…at…a…time, pure clear oil filtered through. Wonderful for kitchen science experiments, lousy for handling 55 gallons at a sitting. Still, it gave me hope.

If you can find a strong, thick-walled container, you can use vacuum filtration to hurry things along. I regularly use a vaccum manifold at work to pull serum through a resin bed to chemically trap a drug I measure. If fibrin or proteins gum up the works, I add some positive pressure to the extraction tubes I use to speed the flow up from glacial to paint-drying. In HPLC (high pressure liquid chromatography), there are radial diffusion columns used that could be used as a filtration set up. This might be beyond your engineering capabilities, though, as you would introduce the oil through the center of a column of filtration material (diatomaceous earth, for instance), have it pass through radially under pressure, and yet retain the filtration matrix. A better setup might be to force the oil through a column of filtration material (top to bottom) under pressure. You would still need a retention base, like sintered glass.


BTW, just for shits and giggles what kind of oil are you filtering, and what are you using the oil for?

Oh. Duh. Sorry ! I’m gathering Waste Veggie Oil ( WVO ) for use in a Diesel Suburban. In the summertime I can do a 50/50 blend. In the bitter cold wintertime ( that’d be now, in the Hudson Valley of NY State… ), barely using it at all, processing and planning.

Eventually I will have a second fuel system installed, and will run the car on 100% WVO.

Google Greasel or Fattywagons for a lot of info on this technology. I am in no way affiliated with either of these guys, though the Greasel guy may get some of my business cause I may buy the pump and accessories/filters from him.

It started out a very very very damned messy proceedure. I am now fine-tuning it, and the mess has been reduced to nearly nil. I have 110 gallons so far, and quite a bit more awaiting me when I get back at the end of the week. I have room out of sight on my property for roughly 800 gallons more to be stored, but only if those 800 gallons are extremely well filtered and ready for automotive use. ( that’s because the filtering happens in one area near the driveway, but I can wheel out and store the “good stuff” farther off, knowing I can pump it back into the Suburban as need be ).

Interesting thing to delve into, for a guy with zero automotive chops. :smiley:


I won’t have to tell you. You will be sitting by the window, suffused with cynical feelings when suddenly and without even a glimmer of visual cue or hint of sound, your corpus will be bathed in said 1920’s Style Death Rays and you as we know you ( the affable and fairly handsome CynicalGabe ) will cease to exist forever.

Hey, can’t say I didn’t warn you. Can I have your iPod, after you’re gone? :stuck_out_tongue:

Pool filter media, here’s a link.

Dia…wha?..earth? What Earth are you from? And, where do I get some? I can buy HUUUGE coffee maker filter meshes from a restaurant supply house, and huge coffee filters also. I could see using them, if the flow rate were acceptable. Just for yuks, I poured a bit of the sample into a coffee filter that I’d rested in a regular kitchen strainer, and sat over a measuring cup.[/QUOTE]

Diatomaceous earth is crushed tiny fossil bits. You’ll likely find it available at a swimming pool supply vendor. The fine media sticks to a more porous media and then does a nice job of collecting crud.

Diamtomaceous earth is not crushed fossils, it is the whole fossils of very tiny one celled lifeforms.

How viscous is this WVO when cold? Will it flow OK, or will it require heating to be thin enough to flow properly? Since your diesel already has a whopping big fuel filter, I think you don’t need to be cleaner than whatever level the fuel filter cleans to. (Pulling numbers out of my ass) If your fuel filter is a 4 micron, you don’t need to filter your WVO to 3 microns. Filtering it to 5 and letting the fuel filter do the rest should be fine.
Anyway my suggestion is get a couple of automotive remote oil filter mounts and set them in series. Use some type of pressure pump. An automotive fuel pump might work just fine* **. Use a sock type filter on the inlet to prevent old french fries from ruining the pump. If you want to get fancy, you could mount pressure gauges at the inlet to the first filer, one between the filters and one behind the second filter. By monitoring the pressure drops in the filters you can tell when it is time to change filters.
One big word of warning. Water is a bad thing. You will need to store your clean fuel away from condensation. If water gets past your trucks fuel filter it will be super expensive to repair. While we are on the subject, diesel fuel can get alge growing it in which also plays havoc with fuel systems. I have no clue if alge will grow in old french fry oil, but you might want to inquire.
*use a gas fuel injection fuel pump, not some $10 helper pump for a car with a carb. You won’t the the pressure necessary to fow the oil with a cheapie.
** In general electric fuel pump don’t suck worth a damn, but they push great. So you may have to design your system to gravity feed the pump.