Adventures with a portable sawmill
By Pat Barden
|Issue #104 • March/April, 2007|
I was raised in the suburbs and spent most of my adult life living in apartments and houses in the suburbs. Dad was career civil service and had no experience with woodworking. As a kid, I remember his entire inventory of power tools consisted of a Black & Decker jigsaw and a drill that was an accessory to an Electrolux vacuum cleaner. His greatest accomplishment as a handyman was to buy a door and put legs on it—that was the family dinner table for 15 years or so. His dad owned a bar in a small town in Minnesota. He was a businessman trying to escape the farm, so he didn’t raise my father as a handyman. Most of my experience with wood and tools was in a 7th grade shop class. I could identify some tools, even knew the theory behind their operation, but most of my experience with wood involved shoddy jobs where pieces didn’t match up. When my wife and I had the opportunity to quit the rat race, it meant we would have to handle a lot of stuff ourselves. Our modest income and savings would not allow us to throw money around and waste things. The price of lumber and my lack of skills had me concerned when it came to building sheds and other structures. The house was adequate, but there were improvements that would be needed—it was a doublewide trailer. Then I found out about portable sawmills.
I think the first article I came across was a fellow selling plans for making a chainsaw mill. This held some attraction for me, and it could also serve as a training project for welding. Shortly afterwards, I met a fellow that owned a chainsaw mill. He couldn’t say enough about it. Then I met a fellow that was building his own house with wood produced by a portable band mill; the wood from the mill went directly into construction without planing or other processing after milling. Hearing about portable mills, and having yet to see one, I figured it was a truckload of gear that was assembled, or a large piece of equipment that had to be towed by a dually or larger truck. So I started looking on the internet for information on portable mills, and was surprised at what I found.
First off, there are a number of manufacturers out there—more than I would have guessed. Some of these manufacturers have been in business for a long time. Second off, portable mills are kind of pricey, many starting at $10,000 and going upward quite quickly from there. That’s a lot of money for me.
They had financing, but we were trying to liquidate debt. I didn’t want to get back on that treadmill, working to pay off a loan and neglecting the homestead (the whole purpose of this exercise). Fortunately, I am in fair health for a fellow past his mid-40s; and my last job, flying a desk, had me so sick of sitting still that the convenience of hydraulics was not a deal-breaker. By focusing on a strictly manual mill, I could reduce the cost (and complexity) significantly.
Don’t get me wrong—I was not planning to lift logs or counting on superhuman strength. I’m just an average sized fellow, and not in that great a shape after 5 years of desk work. With this stuff, leverage is everything. A well thought out arrangement and basic gear from the manufacturer would let a child operate the mill; they just wouldn’t be churning out board feet on the scale a hydraulic assist mill would.
Perhaps the third most important thing I learned about portable mills was that there are two approaches on their construction. A portable mill is basically a piece of track, called the bed, on which an adjustable band saw rolls back and forth. You lay the log on the bed and trim slices off the log with the band saw.
The bed is the frame of reference for the entire mill. If it is not square, the lumber produced will be off. The majority of the mills had a welded bed. There are many advantages to this approach: The bed does not need adjustment and is a single, large, strong part of the mill that everything can be squared in relation to. The disadvantages are obvious: If it gets bent or broken, welding is required to repair the bed, making it more difficult to return it to service.
One happy exception to this construction was Norwood. This company has been in business for more than 50 years, according to their literature, and makes a mill out of smaller, interchangeable components. The advantage of this approach is if the bed gets damaged, only the affected components need to be fixed. The disadvantage is that the bed needs to be re-squared periodically, loosening bolts, nudging parts, retightening bolts. When a new mill is shipped to a customer, it is palletized as components. The first step for any Norwood customer on receiving their new mill is assembly. This reduces the cost, simplifies shipping, and makes the new owner intimately familiar with their mill. That held a lot of appeal for me.
Doing a little comparison shopping, the Oscar 18 by Hud-Son Forest Equipment looked like it had the best price, so far as up-front costs to get a new mill. The Norwood Lumbermate 2000 cost a little more than the Oscar, but could handle bigger logs and gave more bang for the buck. But it was still a lot of money. I found a few online forums that discussed the pros and cons of various mills, so I read as much as I could on the merits of each make and model. The more I read, the more I was swinging towards Norwood. The real clincher was a used Lumbermate selling for $6,000. I looked up the features on the mill and priced it out to $10,000-$12,000 brand new—this was a bargain. I would miss the orientation of assembling the mill myself, but the tradeoff was that it would be ready for use as soon as I got it home. It looked like I had a potential mill; the only thing left was to run it by the boss. She agreed, so I made arrangements to purchase the mill.
We drove from Tennessee to Milwaukee to pick up the mill. The fellow selling the mill was upgrading to something with more hydraulics. The only complaint he had about the mill was that the engine would sometimes stall out at the end of a cut, when the throttle was released back to an idle. This was a problem with the motor more than the mill itself and certainly something that could be dealt with. Included with the mill was a cant hook, log carrier, and a box of blades. Accessories on the mill were toe boards, which raise the log end for first cuts, compensating for narrowing log dimensions; log rollers, which help to turn the log between cuts; and a log loader, a combination of ramp and winch to pull the log onto the bed. This was certainly a complete set-up.
We hitched the mill to our Honda CRV, a four-cylinder SUV wannabe, and headed home. Its length was roughly 20 feet, making it a little awkward, but with some care on lane changes, it was no problem to haul.
We selected a site that was fairly level, dropped the mill, and leveled it to the ground.
We had been cutting trees that were hazards to the house and other buildings, so had a nice stockpile of logs. We had nothing to skid logs with, so the Honda was pressed into service again. A steel cable was tied to the trailer hitch and used to drag logs from where they fell to the mill. As I mentioned, we didn’t have a lot of money for building facilities, so our drying yard is primitive. The local co-op was selling bundles of 12 railroad ties for $90, so we bought a bundle and set them up on the back of the property. A little work with a shovel and we had the tips of the ties leveled out, spaced 18 inches apart. Our other vehicle, a Chevy S-10, was used to transport lumber from the mill to the drying yard.
The mill worked like a dream. A scale on the side of the saw provided a guide for board thickness. There are scales for ¾, 1, and 2 inches with kerf allowance, which is the wood chewed up by the blade. In addition to those three scales, a standard scale marked down to the eighth inch allows calculation of other dimensions, working kerf allowance out in your head. The manual that came with the mill contained a short tutorial on sawmill operation and suggestions on getting a portable mill business running. Having no prior experience with milling, I read everything I could get my hands on. The engine, a 20-horsepower Honda, started without a hitch. The throttle and choke cables were old and required a little manipulation, but were serviceable. All the additional support gear required was a grease gun and a can of 3-way oil.
I never claimed to be a carpenter or a lumberjack. I’m just a cheapo that doesn’t want to pay for lumber when I’m surrounded by trees. So this was a learning experience for me. The first cuts made on a log produced slabs. A slab is a piece of wood that has bark on one side. These are useful as weight for the drying pile. The next cut is a flitch, a board with two flat sides, but bark on one or more edges. For the typical log, you make two cuts on each of four sides—one slab and one flitch. In theory, that will result in a large, squared piece of wood called a cant.
Not all logs are the same, and reducing a log to a cant in eight cuts can waste a lot of wood. The edges of a flitch can be ripped to make good boards—on the mill or with a circular saw. So I tried to make all cuts at dimensions that would be useful.
Stickers, pieces of wood that provide air gaps in a pile of drying lumber, are also needed. Stickers are only ¾ x ¾ inches, so this is a fine use of scrap lumber. We were able to make a variety of dimensions—2×4, 2×6, and a whole slew of ¾ and 1-inch boards of varying widths. Our first project was rebuilding a chicken house that the previous owners had let fall into disrepair.
I read everything I could get my hands on about building with green lumber, and settled on board and batten construction. Board and batten is pretty simple—the boards are put up for the walls and thin strips of wood, called battens, are used to cover the gaps between the boards. These gaps will increase as the wood dries, but a batten of an inch or so will keep the wall relatively weatherproof. For a little over $100, we topped it off with a tin roof (about 10 x 21 feet).
We had hoped to use some of the original lumber after trimming off the rotted parts. Walls touching the ground and a leaking roof had taken its toll. Most of the wall board was too old and in too bad a shape to use, but the internal frame was serviceable. We used the original four cedar posts and the 2×6 beams, but little else. The floor space of the house was roughly doubled by sinking two 4×4 posts into the ground and pouring concrete.
That’s where the first problems started. The old wood was store-bought 2×6—planed and kiln dried. The actual dimensions were 1½ x 5½ or so—when you make a 2×6 on the mill and air dry it, by golly it still is 2×6. In addition, that wood is tough as iron. After bending a handful of nails, it became apparent that the wood would have to be drilled and screwed into place. This did slow down construction, but resulted in a chicken house that could withstand a direct hit.
While green wood and board & batten was adequate for the walls, the green wood used for the floor was a mistake. Drying and shrinking has left small gaps in the floor. Nothing big enough for a mouse or snake, but an annoying flaw.
Because we controlled the whole process, we could use any wood we wanted to. Scraps from the edges of flitches and other odd pieces were suitable for window frames and trim. Slab pieces could be used for internal framing and walls—stuff that you’d never see at a lumber yard. Any smaller scraps left over became kindling for the woodstove. We used hardware cloth in the windows to keep predators out and chickens in, but needed to make some sort of window cover for winter. There again, scraps worked well. Pieces of wood and extra stickers worked to build the window frames. Old plastic stapled to the frame provided weatherproofing.
If you look at the result, you can see a lot wrong with the structure. There is a decided roller-coaster effect to the roof. Some of the odd angles are illusions from the irregular pieces of wood used for window trim. The goal was to provide a uniform, flat surface for the storm windows to close against, not provide straight lines around the borders. Corners were another problem. Most of the difficulties encountered with corners were from making due with lumber on hand and trying to “cut corners” with sloppy construction. Fortunately, extra battens can hide a host of sins and make the corner weatherproof. It is adequate for chickens, gave us experience producing lumber with the mill, and allowed us to make a lot of mistakes before we tackled more ambitious projects.
If we had to pay for the lumber to build this project, I’d hazard to guess $1,000 in materials. Buying materials would have changed our approach too. We could use wood extravagantly to make a sound structure. Budget constraints may have caused us to cut corners.
A few final notes. Our land consists of two ridges and two hollows. This sort of terrain is just not suitable for a tractor, the usual choice for skidding logs. While a Honda CRV may not be suitable for skidding, it did work in open, flat areas. Since then we have purchased a large, used ATV with winch. All that’s left is to find a welder I can barter with to get a skidding trailer made, and I’ll be able to fish trees out of every corner of the property. Of the whole process, felling trees is the dicey part. I have been shown by neighbors that in addition to skill in making directional and felling cuts, a steel cable and ATV provide good insurance on getting a tree to fall in the desired direction. For $40 you can purchase 200 feet of steel cable and hardware. A slingshot, fishing sinker, and quality fishing line will let you get that cable high up over a convenient branch, increasing leverage.
Anchor seal, or good paint, is an excellent idea to seal the end of logs, preventing end checking (cracks). If you use the internet, the two websites that I found most useful were: http://www.forestryforum.com and http://www.norwoodindustries.com