Hey everyone,
Prepping for reporting and really need a set of soil sieves. Does anyone have suggestions on where I should purchase some? I can’t quite justify the commercial grade ones that mirai sells but want something that’s going to last. Thanks for the advice.
You can make your own fairly easily. Make some square or rectangular boxes from 1x3 or 1x4 lumber (nominally 3/4" x 2.5 or 3.25" deep) and cover the bottoms with wire mesh. Most hardware stores will carry 4 and 8 wires per inch. Window screen is closer to 20 per inch. McMaster-Carr is a good source other sizes like 16 and 3 and even 8 per inch if the local hardware store does not carry them.
If you leave the sides long you can set them over a tray to catch the soil that fall through. These are sized for a large motor tray that I slide back and forth of a table - it is easier on the back than shaking by hand, but I have a smaller set for that. These are tapered so they nest and I can do multiple grades at once, but straight sided ones work well and if you make the coarser ones so they just fit inside the finer, lower ones that will work as well.
Very nice. I use these very tubs in my garden available at your local hardware for mixing concrete.
I bought this set. just pick the sizes that you need
They fit over a bucket
That’s the same set I use now. Much better than my original set. Being able to stack them over a 5 Gal. pail and sieve 5 sizes at once is much easier than doing the sieving one grade at a time.
I have these too. I just wish there actually was a 1/16 size. I recently asked Ryan about these and he mentioned that he’d really like a 1/10 size since anything below that really isn’t usable unless we’re talking shohin.
I want to build larger ones, but I really only need that like once a year. If I actually plan ahead I can pre-sift and store the prepared substrate in stackable containers.
Please keep in mind that that mesh size is listed as wires per inch (may be wires per cm in some parts of the world, but I don’t know). The wire takes up part of the spaces so the particles will have at least two dimensions that will fit through a hole that is smaller than the nominal mesh size. Caveat for the purists is that odd shaped particles can twist and turn their way through the not quite square hole.
For example, McMaster-Carr ( Screws | McMaster-Carr) lists several wire diameters for most of their different nominal mesh sizes. For example they list 4 wire sizes for 8x8 galvanized wire mesh with openings from 0.093 inch to 0.102 inch (2.36 to 2.59 mm) - the more expensive and longer lasting screens use heavier wire and have smaller openings. Most of us (including myself) would call this 0.125 (3.18 mm) and be done with it - I call it 3 mm.
As the mesh size (number for inch) increases the the wire size becomes less of a factor.
It would be interesting to know what Ryan feels is the smallest useful particle size in a soil - not in mesh size, but in actual dimensions - inches or mm does not mater since there is an exact conversion.
I really like your design @MartyWeiser. I have made similar wooden trays and sift over a mortar tub as well, but it never occurred to me to notch them and nest them. Thanks for the weekend project!!
I got one from Lee Valley that has three screen sizes for like 20 bucks. Works wonders
I don’t have the skills required to create those kinds of angles. 
For a 1/16” sifter I use an over-sink mesh strainer with expandable handles. They’re available at most stores that sell kitchenwares. I got mine at my local Winco grocery store. You could even check Goodwill to see if they have a used one. New ones run between $15-$30. They’re on Amazon.
For a 3/8” sifter I use this compost sifter:
For all other sizes I use the standard 12” bonsai sifters available at most bonsai suppliers and on Amazon.
Then build the sieves so they are straight sides and get smaller as they go higher in the stack towards larger sieve sizes. I built a couple like this to take out to the landscape supply place that would allow us to do some sifting on site to remove the rocks and the fines. In addition this also works well with the concept of having 1-2 layers of material on the screen - as the particle size decreases we need more surface area.
The angles on these are off by a couple of degrees so I included some inside corner blocks increase the structural integrity. I think I cut 4 or 5 different corner blocks before I liked how they fit.
…you’re a genius lol. Why didn’t I think of that.
Sure you can! The mortar tub gives the angle to you. Build the long sides first, after notching them so you have handles. Then measure the interior, cut, and affix. Well, that is my plan of attack for the weekend. I’ll let you know how they turn out.
You’re probably right. I’m probably overcomplicating it in my head with compound angle cuts. I have some scrap wood. I’m sure with enough trial and error I’d get it. I’m trying to figure out a different handle scenario as well. I’m thinking vertical instead of horizontal.
If you do end up ordering from McMaster-Carr be sure to inquire first on shipping. It seems like they aren’t really set up for small purchases and they don’t have shipping quotes available online during the purchase process.
They definitely seem more set up for B2B purchases.
Shipping for the wire cloth ended up costing more than the pieces themselves 
I have found that they tend to ship small quantities of screen as a flat pack which means a big box. Larger quantities are rolled which results in a smaller box and lower shipping.
@MartyWeiser Do you find window screen to be effective for fines? I have used, and plan to rebuild a 3 tray setup. 1/4 inch hardware cloth for aeration layer particles. 1/8 inch/3mm for my standard substrate. Window screen to remove fines for kanuma/muck & what lies above for shohin and cuttings.
I was able to order this from Amazon for the 3mm.
The other sizes are available from them as well but are also carried at the big box sores and local hardware as they are more common use. I already had them on hand.
Yes, I have used window screen for the finer screen. Most of it is generally closer to 20x20 mesh than 16x16. I also like to use aluminum rather than fiberglass since I think it hold up better. For my bigger screen which is about 18" x 30" (46 x 76 cm) I put the window screen above a layer of 2x2 wire mesh for support.
