Anyone made their own Compost grinder?

[MNBobcat]

Hi Guys,

I'm interested in making huge amounts of compost. We're in sand here. For a number of years I've been thinking about how easy it would be to take the grapple on the bobcat and go out in our woods and take off the top layer of leaves, brush, composted soil and to use that in our garden. However, it would be full of branches and other stuff that would make it not very practical. But if a guy could dump that grapple load of material into a machine that would grind it up and then let it sit for a while...it would be very usable.

I know there are other options like grass and leaves, etc. But I often cut firewood and end up with huge piles of brush that just gets left in the woods. Would be very cool to be able to grind that up for compost and also clean up the woods.

The material from the top layer of "soil" in the woods would be too dirty for a wood chipper and it would be best if it a machine was large enough to take a grapple load at a time. So a wood chipper is out. I can't justify $20K+ for a tub grinder.

Anyone ever build a machine that would grind stuff like this up? Would an old hammermill work?

 

[PHPaul]

Can't provide much input on the grinding process, but I can contribute some information on composting cellulose (wood).

I work up my own firewood from tree length, and I rake up and save all the chainsaw sawdust. I have several 1-3/4 cubic yard totes I keep it in. By itself, it takes YEARS for it to compost.

As you may know, composting is essentially all about the proper ratio of carbon and nitrogen. Wood is, for our purposes, all carbon and you need a LOT of nitrogen rich material to get it to compost in any reasonable amount of time.

The reason I keep mine is that I butcher my own chickens, and I compost the chicken guts by mixing them with the sawdust. Keeps the odor down and provides enough nitrogen that the sawdust composts in a few months.

If you don't have a LOT of nitrogen rich composting material (essentially manure or green juicy stuff like lawn clippings) you're going to be disappointed in the progress.

 

[RalphVa]

I used to get sawdust from our cabinet man. Each barrel of sawdust needs 2# of nitrogen. That's 20# of 10/10/10, if you use the non organic method of giving it nitrogen; that's for each barrel. Sawdust is so fine. If you get it good and wet and the nitrogen mixed in it well, it'll compost very fast. I've done it.

I was buying some organic fertilizer with 18% nitrogen while I was getting the sawdust fairly regularly. Something like blood meal is another organic source but generally kinda expensive.

Ralph

 

[muddstopper]

I like your ideal of grinding the brush. Do a search for ramail wood chips and it will explain why its such a good ideal. Inn brief, when it comes to wood chips, something like 70% of the nutrients a tree contains is located in the first 2-3 inches of the trees outer layer. Branches and bark and small dia wood makes excellent compost material. For several years, I have let the local power right of way crews dump their chipped brush on my property. Every couple of years they might dump 100 or more truck loads. This material will break down pretty quickly without adding any extra nitrogen to it. The nitrogen is already in the bark and leaves chipped up in the woods. The piles do require turning regularly to keep the material breaking down. I use a tractor with FEL to just roll the piles. You can tell if it needs turning by just watching the steam rising off the piles. Plenty of steam, just let it work. Steam stops rising, turn it over.

What I usually do with my composted wood chips is use them for mulch in the garden. I till and plant then use the composted chips to mulch the rows. The composted mulch usually isnt completely composted, by just mulching the top of the soil, the mulch wont rob the nitrogen out of the soil that the crops need to produce and hold in the necessary moisture. Soil microbes will work the mulch from the bottom up and release nutrients into the soil. At the end of the growing season, I just till the mulch into the soil, by the end of growing season, its usually broke down enough its more dirt than compost. I overseed with a ryegrass and let it grow, this helps further break down any left over mulch material. As an added bonus, I keep chickens in movable tractors. Once the rye grass gets about a ft high, I move the chicken tractors over the garden and let them eat the rye grass. Chickens do a pretty good job of fertilizing the garden for next season. They will eat all the grass, scratch up the roots and eat them to, as well as any insects or grubs, and weed seeds down in the soil. Next spring just start all over.

Just for info, 100 truck loads of chipped wood will break down to about 1 truck load of compost. A ratio of 10:1. You get another 10:1 ratio from compost to humis. When that 100 truck loads is fully broken down you end up with about a wheel barrow load of good quality humis, While 100 truckloads might seem like a lot of material, you dont really have that much finished product.

 

[MNBobcat]

Hi Guys,

Thanks for sharing your experiences composting sawdust.

I have more trouble finding browns than greens. I have a big yard. I probably get about 3 yards of green grass clippings each week. If I need more I can mow my 13 acre field. I'll also be getting chickens this year too, which should help with the nitrogen.

The stuff from the woods is already largely composted with just the top most layer being leaves. Any small branches are oak branches.

 

[PILOON]

I sent U a PM.

 

[BHD]

I was thinking about your question, and yes there are the small grinders, that are for a few limbs or what ever, but you stated some like a tub grinder, and some thing would grind a grapple load at a time,


the thought I thinking about, was use a rotatory cutter, AKA bush hog type set up in a tub or a section of a tub,

have not drawn up any thing yet, but say take a mower box and the blades, and mount in a frame, have the blades swing into about a bottom section about half of a tub type holder, with a opening on bottom in the opposite half of the section of the unit with swinging blades, (or a side discharge),

one may need some type of system to rotate the tub to keep the blades/grinder feed, or some type of paddle to sweep tings into the opening of the bottom of the grinder.

on eBay there is a 5' mower kit about $520, "Build your own 5' Medium Duty Rotary Cutter kit, just mount to your deck! ".

I would think one may be able to find a used tank to use for the tub and then built a "grinder" using the mower set up , but in housing it in a frame with bottom and top and edges to May have to put some resistance points in the edges to help it chop things, may be some flat bars welding on the edge side, and top and bottom of frame of the "mower"/ Grinder.

(all I know is if I mow some thing with my rotary cutter, it usually come out in fairly ground up,

the other would be to use a PTO shaft that goes straight in or a 90 gear box if speed changes are need, and make a real hammer mill under the tub.

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I did some looking and came across this ,

http://www.google.com/patents/US4773601

kinda of a mini grinder, but I like the side set up and the way the hammers with hooks work, through the grate/bars. think it could be a possibly for a mini type grinder. that could be built,

down load the PDF, for easer viewing.

 

[Renze]

I think its called bacteria