@Matt what’s the mesh size you go for with stainless screen filters?
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its 42X42 with 0.018 wire diameter. So 42 threads in each direction per square inch. It has 59% open area. Keep in mind the screen is not the filter. It is just a structure for dust to accumulate and create the filter naturally. You can go bigger or smaller. The only reason I use this size is because its thin enough I can cut it with a pair of scissors and yet durable enough it wont wear out after multiple cleanings.
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this is the water filter i mentioned upwards…maybee good for last filtering of the fine dust for small engines…??
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You can’t really tell them apart easily without a ruler and just count the squares. . There is a huge jump in price between about 40 and 20 microns for stainless steel. After that you start jumping into plastic being significantly cheaper for the smaller microns.
You have the right idea. You can buy the backflushable water filter replacement inserts similar to what you have for like 20 bucks down to like 40 microns, then they jump to plastic ones because of expense. I am pretty sure I looked at some replacements that were all stainless steel. They were for like filling up agricultural spayers and commercial water systems.
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Thanks for a lot of good input guy’s, still 2 weeks until filter material should arrive, going to be interesting.
I have some thoughts about to build a safety filter, maybe a smaller cloth filter inside the big ss-mesh filter just like many trucks and industrial diesels use, in that case i build a flange at the top, so the inner filter can be lifted separately for inspection/cleaning. But most likely i just prepare for a “safety filter”.
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I would use something flame retardant like 100% wool for a safety bag.
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I know that Niklas uses this as a security filter.
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Where does he locate it, inline to the carburetor? I have thought about installing a mesh filter in the air cleaner or just in line before it to reduce nasty stuff accumulating.
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Safety filter for dust isnt much of a problem. But for tar, lsuggest thin felt. It lets gas trugh fine, but even small amounts of tar will plugg it up, leting you know aomething is wrong. This probably savedme a few headakes
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Niklas has a safety filter right before the intake, he has a screw coupling (dairy coupling) which is easy to take apart and put back.
But we also believe that soot and carbon are harmful to the engine, not just the tar.
He also uses the bubble can, he has had his engine loose 2 times after getting tar in it with alcohol.
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What happens when soot gets to the combustion chamber? Seems like it would just get pumped out with exhaust gases. It was once common practice to run a small amount of water through the intake to clean the intake runners and valve seats while the engine was running.
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Sorry i havent keep up with this thread, internet has been down for me for a couple days. I guess it’s not a hurry to repair when it comes to smaller villages like where i live.
Jan, that was smart, Niklas using a tea-strainer as safety filter, almost exactly like the safety filters used during ww2.
The safety filter i intended to make i will make bigger, of some kind of fabric, (high temperature) my idea is it will work as a final filter, if some soot goes through the mesh, in that way it also acts as a safety filter.
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Just remembered, i had some “new old stock” safety filters 
Svedlunds spare safety filter.
Inside, haven’t counted the mesh size.
Read somewhere these filters mesh was made of bronze, brass becomes brittle and due to vibrations falls apart, wich the engine then digests…
This one is probably GM-Svedlunds, for Opel, or maybe Gragas?
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Latest progress: test-assembly of the bottom part.
Measuring for new mounts.
Temporarily installing the gas pipe, to get everything in right place.
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How are these installed? Is there a flanged pipe near the engine?
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Im going to find a pic of some of these filter-mountings, these was often of a easy-to-use construction, just a wing-nut, or a simple locking mechanism to reach the filter, if it had been cumbersome to reach or clean the filter, people had just omitted them out of lazyness.
Often a box of cast-iron, with a lid on top, the filter inside hold in place with a spring.
Källe gasifiers had a very popular safety filter, just like a round air cleaner, as used on the WK-builds, but this had metal-mesh inside (metal shavings) mounted after air-mixer.
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I may use my air cleaner hat to hold a circular filter. Remove the paper and install some stainless screen.
I don’t think the WK guys leave their air filters in place, they usually replace it with a pod filter.
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Yes, i believe they dont use the filter cartridge, anyway, heres some pic’s of filter-boxes.
Universal, hose-mounting, for cone-shaped filter.
Cast-iron box, hose-mounting, the lid is hold by springs, to give a explosion relief, filter mesh is “slide in” in two grooves.
Filter mesh for above.
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Not so much progress today, my back is hurting after yesterdays chainsaw running 
Anyway i prepared the hopper for assembly, flushing the bottom gutter. And some cleaning.
After i ran it with clogged condensate collector i got some serious cloggings of burned tar in the gutter.
Here is a wiew down the hopper, the cone is normally hanging loose near the bottom, here i’ve pushed it up for cleaning.
I decided to put one more “drain” for condensate from the hopper, this collector is going to be mounted near the bottom part, to use som heat to keep it flowing better.
The collector i use now is recessed in the bed, placed directly against the exhaust to heat it some, to keep the tar flowing, and keep it from freezing.
Hopper lid, im going to build a new one, just to come up with a idea how to press this convex shape.
And… i read somewhere that Wayne (ofcourse
) came up with the best idea with his hopper condensate collector? This really solves many clogging problems, i dont know if this is a WK secret? Or if somebody knows where i may have read about it?Anyway it was a super-solution, great idea!
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