Fw: Compost screens compared: Cantopper vs A-frame

Square Foot Gardening List - http://www.flinet.com/~gallus/sqft.html

 
By popular demand, here are the Cantopper instructions

 
Dear humus aficionados:
 
I  did a little trial a while back on some two year old vermicompost I had in the yard, screening it through two screens both made with 1/2 inch hardware cloth.
 
One screen was an A-frame 5 feet long and 3 feet across, set up on a 45 degree angle on a large tarp. I tossed 47 liters of compost on the screen; then I sifted the rejects through the Cantopper, which is a large riddle 18" across that sits securely on a Rubbermaid trash can 32" high, which can be rocked back and forth or from side to side, or in a rolling motion around the rim of the can.
 
18 liters of compost made it through the A-frame on the first toss. Of the A-frame rejects another 25 liters sifted through the Cantopper; 4 liters of rejects remained.
 
This compost was moist; dry compost might fare better on the A-frame, but I prefer not to dry compost if at all possible, because this destroys some of the microbial value.
 
These results indicate to me that the Cantopper is tops as a backyard screening tool; it is light in weight, easy to use, operates cleanly and efficiently, and takes up little space in the garage or tool shed.
 
Here's how to make one:
 
Materials: one piece of plywood 2 feet by 2 feet ( I use 3/4 inch exterior grade)
                    one piece of 1/2 inch hardware cloth (1/4 inch can also be used), 20 " x 20"
                    one 60" length of 6" plastic garden edging
                    three 1" x 2" x 1/2 inch blocks of wood
                    heavy duty 9/16" staples
                    6 1" wood screws
 
Tools: saber saw (aka hand jig saw), heavy duty staple gun, screw driver
 
First, choose a trash can that is sturdy and suits your height. I prefer the tall 32" can, since I am a tall guy who prefers to work standing.
 
Now take the can and set it, open side down, centered, over your plywood square. Use a pencil to trace the outline of the can; this will serve as your reference for cutting out the inner circle of the plywood (go 1/2 inch inside the line) and for placing your three stops, which go on a tangent right at the line, after the screen is placed.
 
Cut out the inner circle 1/2 inch inside the line. The resulting disk makes an excellent single line swing; I drilled out a 3/4 inch hole in the center of three of these and hung them on the maple tree in front by 3/4 inch rope, which is so sturdy even I can swing on them...:-) (Wastenot, wantnot, as they say..)
 
Place the screen on the hole, center it and staple it into place. Use plenty of staples.  I have found it useful to take a tack hammer and nail the staples flush to the plywood.
 
(My latest idea to improve it is to sandwich the screen between a thin piece of plywood and the main piece, instead of stapling it, to reduce exposed screen edges, which can be annoying...or wrap in duct tape, the universal fix all....:-)"Wood always moves, Rust never sleeps, ducttape fixes everything!")
 
 
Place the three stops equidistant on the drawn circle and screw them into place. These will hold the sifter to the rim of the trash can during sifting, and further secure the screen.
 
Now turn the plywood over so that the screen is on the bottom. Put the edging material into place and secure it with staples, tacked in as with the screen. Where the edging comes together it is useful to secure the top part of it; I make a couple of holes with a drill bit and tie it  together with cable ties. (I now find about 8 small screws to be a little better than staples, if harder to place)
 
For fellow residents of Canada, the edging I use is from Canadian Tire and costs about 2.50$ for 20 feet, enough for four sifters. The other materials cost about eight or nine dollars, so the whole thing can be made for ten bucks or so in less than an hour. Not bad, eh?
 
I hope to see my photos of the Cantopper up at the Master Composter website, www.mastercomposter.com , in the next few months or so.
 
I should note that the way to use the tool most ergonomically is to empty the trash can every three or four hoppersful of material, sometimes even more often, as it is easier to rock the can when it is mostly empty. It is also easier to empty when lighter rather than heavier!
 
As far as screen sizes are concerned, I now have five sizes on the property: 1 7/8, good for the original break up and fluffing of material in a tight bed; 3/4, which I may use to presift some chipped branches in the future, but haven't used yet; 1/2 inch, which has always been my general purpose compost size before the worms really started getting into my head....:-)
 
1/4 inch is the size that separates most of the larger worms from the smaller materials; it is the size Larry Martin suggests is the best general purpose size in a harvester.  See his website, in the catalog, under Worm Harvester for more info....www.vermitechnology.com
 
1/8 inch screen is what will give you almost pure castings and few if any worms or cocoons.
 
It should be clear that 1/2 inch is easier than 1/4 inch to sift, and 1/8 most difficult of all, given that the holes get four times smaller with each step down, so that 1/8 inch is 16 times smaller than 1/2 inch materials.
 
Nowadays 1/4 and 1/8 inch are what I am doing most of my worm compost work with, since the quality of the 1/8 inch is truly excellent, and saves the worms for new career opportunitiies in other piles....
 
You can dry the material some for easier sifting, or use a masonry (harper) brush to clean the 1/8 screen between sifting....
 
I just want to point out that this is an artisan-type method, inexpensive but somewhat labor intensive; the bigger trommel type screens are probably the way to go for large scale harvesting....
 
So there you have it, the latest in Cantopper thinking, from a man who sees a trash can as a many splendored thing--now wheelbarrow, now composter, now sifting receptacle---and you can fill it a third full with multiple potting soil ingredients, and roll it around on its side too---cheaper than one of them OdJob thangs....enjoy!
 
Oh yes, you can also use a Cantopper as a garden harvest basket.....you can put wet stuff in it to drain off....you can wash root crops off in it....you can take a weed wacker and shred leaves into the trashcan, using the screen to ensure fine size reduction....a real multi-purpose tool! (Use eye protection and a dust mask for that leaf shredding thing, eh?)

 
Email me if you have other questions, please.
 
Good composting,
 
Frank Teuton
 
January 12, 2000
 
 
 

 

 
 
 
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