I've got this wierd idea and I'm wondering what you guys think. I've got an old sawmill I've been putzing around with in my spare time and it looks like this year will be the year that I'll actually fire it up after just a little more dinkin. Anyway, it has a 3/8"kerf. Translate that into every two passes with the saw I will have generated one 3/4" boards worth of sawdust. In other words if I use it quite a bit I'll be generating ALOT of sawdust. I figure I'll use some of it for composting, maybe some for animal bedding and the rest I've been thinking about turning it into firewood. Heres the idea.

Generally when you saw logs they are green and moist. If i stuffed a bunch of it into a 6" x 16" pipe and compacted it with a hydraulic cylinder so it was really tite i'm thinkin it would make a long burning piece of firewood, comparable to particle board. The question is would i need a binder to keep it together when it was taken out of the pipe, if so what would you use as a binder? Its possible that because its cut while green and compacted titely the lignin in the wood would do the job----or not. I've also thought about mixing a wee bit of drain oil with it to add btus and possibly help it stay together.

Once the mill is operational this is how I'll be making my firewood, not necessarily with the sawdust but with the slab wood. I figure if i expense the cost of the logs, assuming I have to buy them rather than custom sawing in the neighborhood, against the product and revenues from sawing then my firewood will cost less than nothing. Thats the idea anyway. Any thots on binders? Thanks

-- john leake (natlivent@pcpros.net), May 11, 2000

Answers

If your sawmill is anything like ours, there is always "a little more dinkin" needed. What brand is it and what size blade?

Two ideas I've come across but don't remember where I saw them are 1) mix a bit of old oil in using a cement mixer (but then to clean the mixer???) 2) use an old trash compactor to compress the sawdust.

I don't think just green sawdust compacted would have much integrity, there isn't really anything to glue it together. I've never used a trash compactor, but it seems like you don't have to have a full load to run the thing. It might be possible to put 2 paper bags in side by side with equal amounts of sawdust and get a reasonable log out of them.

Drain oil would contain a certain amount of lead as well as other contaminents. Doubt logs made with them could legally be sold, so what about parafin? That's what I was planning on trying. I've also wondered about making wallpaper paste or thinning an Elmer's type glue and mixing that in. If you come up with any workable solutions, let me know. Gerbil

-- Gerbil (ima_gerbil@hotmail.com), May 11, 2000.

Parafin or drain oil would burn better than paste or glue. Isn't this similar to those fireplace 'logs' that are sold in stores? I don't know how well they burn, but maybe there is a label on them to say what is in them -- seems like everything else has a label these days. Personally I think I would just use the sawdust in the compost and for animal bedding. I've also seen it used for insulation -- possibly for an outbuilding that you wanted to heat part of the time?

-- Kathleen Sanderson (stonycft@worldpath.net), May 11, 2000.

They sell these logs from lumber mills in Idaho. Check with the lumber industry and I bet you'll find your answer. They burn long and hot and are really a recycled product that works.

-- Anne (HealthyTouch@hotmai.com), May 11, 2000.

Gerbil: The mill itself is homemade and theoretically portable but i've set it up as stationary. It's built on a greyhound bus frame. It will handle a log 16' long and up to 24" in diameter. It has two 30" blades, a hydraulic log loader and a sawdust blower. The carriage moves by a hydraulic motor. Whoever built it had some good ideas as far as design goes. It is powered by a 3/4 ton chevy truck drive train with a 250 cid in-line six cylinder engine. The driveshaft from the truck transmission is coupled to the mill. It will be necessary to run the transmission in reverse to get the right rotation on the blade which brings me to another question. Does anyone know what the gear ratio of the reverse gear is? Its a 67 chevy with a truck 4 speed. I've been told its around 4-1. I need about 750rpm at the input pto on the mill to give me 560rpm at the blade. If its 4-1 then the engine rpms will be around 3000rpm---a pretty good fit into the power curve of the engine if my info is correct.

The main reason I'm thinking the green wood might bind under high pressure is because of the lignin, the natural binder that holds the wood together.

Kathleen: I like the insulation idea, however like I said, if I do alot of sawing I'll be making alot of sawdust. I spose tho if you composted sawdust with chicken manure and/or alfalfa it might break down pretty well. I suspect its goin to be a bunch of experimenting to find the right combination of applications for the stuff.

-- john leake (natlivent@pcpros.net), May 11, 2000.

John, I sent you an email, I figured I'd spare everybody else all the gory details. Probably aren't too many of us interested in sawmills. Gerbil

-- Gerbil (ima_gerbil@hotmail.com), May 12, 2000.

Lignin is sort of like cellulose (or plastics) - it's a long-chain polymer. I don't think just the pressure one could work up in a farm- workshop type arrangement would make it re-bond, even if you heated it.

I read somewhere they're even running domestic heaters on maize seed these days. Maybe if you found a cheap source of starch (say hammer- milled grain?), and made boiled-starch glue like kids use, it would work.

The arrangement you've described - would it help to case your artificial logs (line your cylinder) in a couple of sheets of newspaper? I've also heard that it helps with burning artificial logs if you leave a hole down the centre - say a greased rod that you pull out after it's made. Also helps with drying.

-- Don Armstrong (darmst@yahoo.com.au), May 12, 2000.

Good ideas Don. I thought about corn starch from the store and was wondering if it would attract bugs, once mixed with the sawdust? I've been thinking about contacting the forest products lab in Madison to see what they will say. I'm not in any big hurry on this so I've got some time to check it out.

-- john leake (natlivent@pcpros.net), May 12, 2000.

John, I have been on the Internet for 4 hours trying to find some info on making fuel bricks out of pressed grape skins. It was an old use for the waste, not used anymore evidently. I have been unable to find any info on the subject. When I ran across your question for binding sawdust, I thought I'd throw my dilemma into to mix too. I need to know about a binding agent too. If you find anything to be successful, let me know. I'll let you know if I come up with anything too. By the way,I have made good fire starters out of sawdust and parafin, using egg cartons before. I think I'll try parafin first.

-- Cathy Thorne (busymom5989@aol.com), January 09, 2001.

John, We just got our newest Farmer's Advance and there on the front page was an article on soy based glue in plywood manufacturing. I am wondering if some part of it might be useful to you. I don't know if they have a website but the project was conducted by Agricultural Research Service (ARS) scientist in Peoria, IL. The United Soybean Board provided the funding for the project. Farmers' Advance has a web site www.farmersadvance.com - I don't know what they have there. If I could figure out how to use this high priced scanner to scan into a word document I could cut and paste and send it to you. (maybe if I would stay off the forum I would learn how???)

-- diane (gardiacaprines@yahoo.com), January 10, 2001.

Ok guys, it's not quite as easy as one would think. Where I work they have their own in-plant pallet maker. After re-sawing cants to make the lumber our pallet maker has about a 1/4 ton of sawdust that he has to get rid of. Although putting it in the garden is all well and fine, thats alot of firewood if one could figure out a way to make logs out of it. After doing a little (about 15 hours worth) research on the internet, I came up with this site which I think can answer most of everybodys questions. "http://www.fao.org/docrep/T0275E/T0275E00.htm"

>http://www.fao.o rg/docrep/T0275E/T0275E00.htm I'm new at this clickable link thing, I hope it came out right.

-- emory (et@hazleton.net), March 25, 2001.

Yep! I messed up. You'll have to type the adress in because I don't know how to fix it. Sorry emory

-- emory (et@hazleton.net), March 25, 2001.

Driving through Springfield, OR a couple of years ago I saw a Kingsford (sp?) charcoal plant that was using sawdust to make the bricketts. Maybe there is something on the WEB describing this process?

-- Lynn Goltz (lynngoltz@aol.com), March 25, 2001.

If you go to "Duraflame.com" you might get some information. Enjoy your life.

-- Deborah (bearwaoman@Yahoo.com), April 08, 2001.