Bonsai Soil Sieves

Hi All,

I've been looking at various sieves for processing bonsai soil.
It seems there is some degree of variation on what some determine is preferred for small, medium, and large aggregate.

As for product, honestly, most of the sieves I've seen look rather flimsy, laborious, and slow.
I'm not faulting anyone for making these choices, but having a almost ancient experience in construction materials inspection, I'm thinking I'll prefer to get some more proper fixed size sieves and fabricate a shaker.

But the question then remains, what sizes are a proper delineation for small, medium, and large aggregates.
I've seen 1/3", 1/4", 1/5", 1/8", 1/10", 1/16"

So, Here I ask, what gauge sieves do you all use for which grade soil?

Thanks in advance!

I can answer. but in mm's.

My two inorganics are set as 5 mm , basically what sits on the screen at 5 mm and has passed through a 6 mm screen.
The aged compost is what has passed through a flour sieve.

For the mame' [ plants at 6 inches or 15 mm ] I use 3 mm inorganics.

Fortunately, I can purchase the silica based gravel pre-sifted at roughly 100 lbs around 5 mm.[ about $7.00 US ]
The crushed red earthenware brick I get from the brick factory room of crushed brick. It takes about
3 hours to get enough to last 3 years or so.

I also re-use the inorganic when repotting, and that saves on having to get more.
Essentially a day sifting of compost and inorganic and I have enough for about 3 years.

In the yard under the Avocado tree, is about 3m [ 10 feet ] x 3 m x 1 m high dedicated to compost making -
bamboo, leaves and weeds, plus the leaves of Leucaena tree [ equal to the manure of a rabbit ]

The sieves, start at 2 x 1 foot and then go to simple rounds about 8" x 2.5 / 3 inches deep.

Possibly about 400 plants, takes about 6 weeks to repot.
Please note only about 50 could be called / possibly called, Bonsai.
Laters.
Khaimraj

My experience is in powder processing so I think in terms of mesh size - wires per inch in the USA. For the large particles using relatively fine wire found in most sieves and screening the particle size is very close to 1 over the mesh size so I use that for the size. I make my sieves from hardware cloth (lightly welded wire mesh) and window screen for the finest one. Here is now I define my soil.
Large -1/2" / +1/3" (-13 mm / +9 mm)
Medium -1/3" / +1/4"(-9 mm / +6 mm)
Small -1/4" / +1/8" (-6 mm / + 3 mm)
Very Small -1/8" / +1/16" (-3 mm / +1 mm)
I actually have the bins labelled in mm since it is easier to write, but it confuses some of my visitors.

I primarily use the large as a drainage layer in the bottom of larger, deeper pots or grow boxes with 1/4" hardware cloth in the bottom. Most of my trees are potted in either medium or small and sometimes a mix of the two. Very small is reserved for seed starting and sometimes as a top dressing to help get some moss growing.

I have built both tapered wood trays that nest for sieving small quantities of soil and a rotary system composed of concentric screens from 1/2" to window screen for larger quantities. Info on the later is in a thread somewhere on the forum.

Thank you to all who replied !

@ Khaimraj,
Am I to assume you only sieve your inorganics?
I’ve seen this practice also in India.

@Marty,
Thanks for all the specificity, that is exactly what I was looking for.
I went and looked up your rotary system and that is pretty cool.
All I found though was one picture on someone else’s thread.
If you have a main link to more detail, that’d be appreciated.


As an experiment I bought the Joshua Roth sieve that comes with 3 interchangeable sieves.
Ehh, pretty much what I expected.
I mostly wanted to see what kind of percentages of distribution I could expect from my Akadama (Double Red Line brand) and expanded shale.
(please don’t start making fun of my Akadama I know most of you either don’t like it or think it’s stupid)

The interchangeable sieve from Joshua Roth is flimsy but serviceable (at least for awhile).  It works, but confirmed what a PITA it is to sieve the same material three times (because they don’t stack).

I have a background (from a long ago former life) in materials testing so I already knew about stackable ASTM sieves and electric shakers.
What I didn’t know is how CRAZY EXPENSIVE new sieves and shakers are.
One sieve can be $350 to $600 and an entry level shaker starts around $2000.
However, I did some digging and found pretty decent used sieves on eBay in the $30-$60 range and I can make a shaker for cheap.
Certainly good enough for my purposes.
It’ll probably take some time before I can acquire the size sieves I have decided buy but I’m in no hurry as I don’t plan any repotting until late winter early spring.

For reference purposes, I put together a table showing some of the ASTM sieves (I didn’t bother with anything over ½”).
For relation, I also show where the Joshua Roth sieves line up (blue cells) along with their actual measured opening.
The sieves I think will work best are marked with green cells (dark green I already managed to find).
I tried to line up mostly with the size categories of Marty’s specifications but I admit there may be other preferences.
The reason was that I felt like the finished categories through the Joshua Roth sieves were not making best use of the materials.
For example, using JR sieves, anything larger than ¼” is too large and yet the small size goes into what I would call extra small.
I think, at least as a starting point, Marty’s size breakdowns are pretty reasonable and make better use of the material.



One thing that surprised me was how much of the Akadama was actually too large.
I bought a 2Kg bag of what is described as “medium” but almost all of it stays on top of the ¼” Joshua Roth sieve.
Later I’ll probably try to devise a means to lightly crack (without crushing) the larger pieces so I can get it down to actual medium and small.

Anyway, sorry to ramble on but hopefully it may be of use to someone after me and thanks again to Marty and Khaimraj.

Bilbo,

firstly, I don't think the @ feature is activated on IBC, as it is on Bnut

Secondly,
I sieve the compost down to flour sieve size, because as the compost ages to become humus.
it glues it self together to match the 5 mm inorganic..

I have given up on measuring sieve openings, as Europe uses mm and US uses inches.
It is confusing. But the chart is appreciated. If you don't mind I will copy it to a file.

Much as the spell checks leave me clueless. We speak something akin to the Queen's english
Laters.
Khaimraj

Hi Khaimraj,

Thanks for your reply.
I wasn't intending to use any feature with the "@" just letting you know the comments were for you specifically (Since i had delayed in responding).
Certainly, fee free to copy the picture locally, that is why I put it up, to be useful.

A point of clarification on the Joshua Roth interchangeable sieves.

They are advertised as 4, 5, and 10 openings per inch, and they are.
However, the reason the actual size openings don't directly align with the ASTM scale is the JR mesh uses wire of sizes which are different from the ASTM standard with which to form the mesh.

So, yes, the openings per inch are indeed what they claim, but my actual measurements of the openings (micrometer precise to .001") do not align with the ASTM standard.
Since my table was focusing on the actual opening, thus the JR large and medium sieves do not align by designation, but rather by opening size.

this is what i came up with and built...

https://ibonsaiclub.forumotion.com/t16490-soil-sifting-convertible-rolling-work-table#177062

it has served me well but i sold it a few weeks ago to make room for something a bit bigger, for larger production of my "north american" substrate mix (nothing imported)... which i will be marketing under my Wisco Bonsai banner...

i simply used the closest thing available for screen sizes that my local hardware store carried which was really pretty good, but for the next one, i will be getting the particle size a bit closer to optimum (being 3/8" for large and 1/4" for medium and 1/8 for small)

I use a colander to sift soil.

only sifting the fines outta napa DT-earth, right mike ?

All very ingenuitive designs to be sure and I'm certain there are many more.
I have a few in mind myself.

I'm just not feeling very handy dandy DIY lately.
I had a heart attack in April and undergoing yet another catheter procedure this Tuesday to hopefully rid myself of these god awful debilitating meds.

In due time, I'll be back to my normal get-er-done self and tackle the sifting of soil from a larger perspective.
In the mean time, money can do for me what I can't do myself.
Getting fully set up for proper bonsai is no small task.
Summer is a busy time for the trees alone, must less rain water system, soil system, shelves, etc.

Thanks for all the insights and I don't want to seem unappreciative, I'm just not in a position to build an engineered sifter yet.

In the USA larger sieves are designated by the number of wires per inch. This is often called the mesh size and extends to at least 325 wires per inch so it easily covers the range for bonsai soil. As a result you have to subtract the wire diameter from the nominal size to get the actual size of the openings. In addition, there are two common types of wire cloth - welded wires where the two wires are in different layers and woven wire cloth where they alternate over and below each other.

I built most of my sieves using what is often called Hardware cloth in the USA which is a welded wire cloth that is frequently sold based upon the nominal center-to-center wire spacing. For my finest sieve I used window screen which is woven and 14 x 14 mesh. Today I did some measurements with a set of digital calipers and obtained the following results.

Mesh          Wire (inch)     Opening (inch)        Opening (mm)     My size label
2 x 2           0.035               0.465                    11.8                    12 mm
3 x 3           0.031               0.302                      7.7                     9 mm (opps, a bit large)
4 x 4           0.022               0.228                      5.8                     6 mm
8 x 8           0.015               0.110                      2.8                     3 mm
14 x 14       0.016               0.055                      1.8                     1 mm (opps, a bit small)

I bought all but the 3 x 3 locally and ordered the 3 x 3 from McMaster-Carr. Someone said they were looking for 3/8" = 0.375" for their larger size limit and McMaster-Carr carries some heavy wire 2 x 2 mesh that is nominally 0.38" openings, but I was being cheap when I built mine.

In addition to the rotary sieve system I also built a series of stacking box sieves a few years back using all 5 meshes above that work very well for smaller quantities pictured below (sorry about the water drop on the camera lens). Finally I use the 4 x 4 in bottom of my grow boxes and to cover the drainage holes in most of my pots for very good drainage.

bilbo wrote:All very ingenuitive designs to be sure and I'm certain there are many more.
I have a few in mind myself.

I'm just not feeling very handy dandy DIY lately.
I had a heart attack in April and undergoing yet another catheter procedure this Tuesday to hopefully rid myself of these god awful debilitating meds.

In due time, I'll be back to my normal get-er-done self and tackle the sifting of soil from a larger perspective.
In the mean time, money can do for me what I can't do myself.
Getting fully set up for proper bonsai is no small task.
Summer is a busy time for the trees alone, must less rain water system, soil system, shelves, etc.

Thanks for all the insights and I don't want to seem unappreciative, I'm just not in a position to build an engineered sifter yet.

Best wishes to your health, Bilbo.

marty - i did a search for your rotary system, using just the word "rotary" but was unable to find it...

a rotary type system is something i was considering...

if you have the time to find a link to your post, i for one would be most appreciative !

Just get well and strong Bilbo,
Laters.
Khaimraj

kevin stoeveken wrote:marty - i did a search for your rotary system, using just the word "rotary" but was unable to find it...

a rotary type system is something i was considering...

if you have the time to find a link to your post, i for one would be most appreciative !

There is a picture of Marty's rotary system in your thread which you linked above.
This is the reference I was able to find which I also mentioned but yes, a more detailed and descriptive thread would be greatly interesting to me as well.

@ Lance and Khaimraj,

Thanks, tomorrow is the day...

I may have only posted the picture of the rotary sieve system in a couple of other threads. I will see about putting together a couple of drawings and posting them in a new thread along with the original picture.

bilbo wrote:

kevin stoeveken wrote:marty - i did a search for your rotary system, using just the word "rotary" but was unable to find it...

a rotary type system is something i was considering...

if you have the time to find a link to your post, i for one would be most appreciative !

There is a picture of Marty's rotary system in your thread which you linked above.
This is the reference I was able to find which I also mentioned but yes, a more detailed and descriptive thread would be greatly interesting to me as well.

ha !
right under my nose !!!
Thanks B !!!

but i gotta say, that things look like it is outta my league to build !!!
props marty !!!

kevin stoeveken wrote:only sifting the fines outta napa DT-earth, right mike ?

Yep.
I use lava now too.
I just wash it out with water.
In the same colander.
I used to only use just the Napa 8822 unseived but since I started using lava in there and all fine pieces are out my trees grow much better.

M. Frary wrote: I use lava now too.
I just wash it out with water... ...

I use lava, too. And I do wash it of course. Lots of fine dust!!!
After sieving I keep the coarse lava sand and use it for cuttings.[/quote]

right on mike... glad to hear you have incorporated lave now !
(i no longer use the napa)

My opinion and you can take it anyway you like. Most sieve systems are better at producing sales to beginner and early level growers that want to do anything and everything "bonsai" they become aware of than actually producing recognizable results. Sifting soil is better than using it right out of the ground but there really is no necessity to obsess over strata and levels in a pot of particles of this size and that size. Sifting a soil mix should only be done to remove the dust from a soil mix. You can do all the fancy stuff you wish but after fifty some odd years of growing bonsai I have found that much of what we are taught and sold as gospel is bovine scatology. Most of the time a fine window type screen will do the job quite nicely and will cost you very little. At a time when you should be encouraged to provide the basics for your trees and lean how to style and wire and prune, many of you are making a big deal out of the dirt wars.

Vance Wood wrote:My opinion and you can take it anyway you like.  Most sieve systems are better at producing sales to beginner and early level growers that want to do anything and everything "bonsai" they become aware of than actually producing recognizable results.  Sifting soil is better than using it right out of the ground but there really is no necessity to obsess over strata and levels in a pot of particles of this size and that size.   Sifting a soil mix should only be done to remove the dust from a soil mix.  You can do all the fancy stuff you wish but after fifty some odd years of growing bonsai I have found that much of what we are taught and sold as gospel is bovine scatology.  Most of the time a fine window type screen will do the job quite nicely and will cost you very little.   At a time when you should be encouraged to provide the basics for your trees and lean how to style and wire and prune, many of you are making a big deal out of  the dirt wars.  

But Vance.
How can places Bonsai Mirai ever hope to sell expensive sieving screens at exorbitant prices if you go and let this information out?

Vance Wood wrote:My opinion and you can take it anyway you like.  ... ... I have found that much of what we are taught and sold as gospel is bovine scatology.

I am the one who will take it as sound and clever and logical!
Mr. Wood, where on earth have you found this word "scatology"?
Is there such a word in English? I haven't heard this until now!
This is a word of Greek origin : σκατό < medieval Greek or σκατόν, which plural is σκατά and comes from the ancient word σκῶρ (genitive : του σκατός)