The Moss Sawmills Process From Log to Lumber
I’m sure some of you when thinking the word “sawmill” think of a 2×4 and 2×6 to build your house with, but here at Moss we run a different kind of sawmill than most would think. We process 4/4, 5/4 and 6/4 mainly for the flooring, furniture and cabinet markets. The other dimensional mills saw mostly 6/4 and specific widths. This gives a finished product of 2×4, 2×6 and so forth.
While other mills process mostly softwoods to produce building materials, our sawmill is more focused on processing hardwoods for the furniture market. We just worry about the thickness and have random widths. This way the plank can be cross-cut to get the best cutting possible for the application needed.
Other finishing operations can cut the board down so no defects are showing in the smaller cutting if need be. This process can be very complicated and will be explained more in future post. In this post I will try to explain the process from start to finish here at Moss Sawmill.
The first step in the process is getting the logs. We buy our own timber when possible and contract independent crews to log them. We also buy logs from other loggers and individuals. When the log truck arrives on the yard the loader drivers unload and put the logs in long runs. When these logs are laid on the ground the log grader measures the little end to see the circumference of the log. The log are then tallied according to size and grade. The bigger the log, the more footage it has in it and thus the higher it can be graded.
The most common grades are from highest to lowest; Veneer, Prime, 1 Common, 2 Common, and 3 Common. These grades are the difference in thousands of dollars to the mill and the loggers. For example; the range on the same log can be from $1.525 per foot all the way down to $.16 per foot. So depending on the quality of the log, one 500 board foot log can bring $762.50 or all the way down to $80.00. So the log buyer has to be very knowledgeable of his trade to be fair to the mill and the loggers at all times. After grading, the logs are piled up into runs with all the species separated from each other. The species that we separate to saw are: Poplar, Ash, White Oak, Red Oak, Hard Maple, Soft Maple, Hickory, Walnut, Basswood, Beech and Cherry. All other species are considered pallet logs.
After learning the sawing schedule for the week, the logs that are to be sawed are put onto the log in feed chains. The first process is to debark the logs. This machine rotates the log and a spinning cutting head grinds the bark off the log. Think of this like an electric pencil sharpener without making the end to a point. This is done to get all the rocks and foreign objects off the log so the band saws will not be damaged or dulled. This bark is later used for mulch at our sister company Barky Beaver.
The next process is to cut down the logs into boards. The sawyer will already know what thickness to cut the boards down to. The logs will go to either of the two head band saws. Where they will be rolled on the saw carriage by a hydraulic arm and dogged/clamped into place. The sawyer has to position the log to make the best yield possible. The log carriage rides on a track and is pulled back and forth by hydraulics and/or cables. The first pass cuts the outside edge of the log producing a flat side. The cut off or “slab” is carried down a belt to a chipper where it is made into wood chips. If the log is good enough the sawyer will take multiple cuts on this side to produce boards.
After the sawyer takes off the optimal numbers of boards from that side he flips the log so the flat side is on the bottom of the carriage and repeats the process until he has a square cant. He cuts the cant down until he gets close to the heart wood or starts to see a lot of defects. Then he makes the saw cut a flitch that is sold to make pallets. He can also just cut the cant to four square sides and send it to another mill called a re-saw (run-around). This mill is located between the head saws so either can feed it cants. This mill has no carriage that goes back and forth, but instead has a line bar that sets the thickness as chains and rollers pull the cant through the saw. The cants go around and around a set of chains that keeps taking another board off on every pass. Since this saw has nothing clamping the log down, it can saw all the way down to a 1 inch board, and can saw around 8 boards a minute.
The first boards to be cut off a log will still have the bark on one or both sides. After the first boards are cut they will be run through an edger to rip the live edge sides off. The edger has a minimum of two saws that can be adjusted to different widths. A laser light shows the saws orientation on the board. The edger operator lines up the lasers so that the edge is taken off and leaves the good wood in the center of the saws to be carried away to the green chain.
After the lumber and flitches are all sawed, they travel by chains to a set of osculating rollers that even end them, so they will be uniformed before going into the sorter. The sorter/lumber grader looks at both sides of each board. He then hits a button that grades each board. The grades we use are FAS, 1 Com, 2 Com, 3A, and frame. FAS is short for first and seconds, and is the best boards with no or very few defects. The rest of the grades follow on down the line from best to worse. The grader can also trim the boards on each end to make the most aesthetic looking board possible. Every board gets even end trimmed and cut to the longest length obtainable. All boards are cut to 3 inches longer than the closest whole foot. So a board that is 10 foot 11 inches will be trimmed back to 10 foot 3 inches and so on for all lengths up to 14 foot.
After the boards are graded and trimmed to length they get carried one by one to a bin that is assigned by a computer. Each bin will be separated by the grade and by the length. When the computer calculates that the bin is full, it will stop adding boards to it. When the bin is full it is dropped down onto another set of chains that carry it to a stacking machine. The stacker places the boards in single stacked layer that are around 38 inches wide and 34 layers tall. When the pack is full and tightly stacked together he puts a couple of metal bands around them. He staples the computer printout onto the pack and paints the grade on the side. The pack is then picked up by a loader and loaded on trucks to be transported to GF Hardwoods to be processed further.
A lot of hard work and some masterful engineering has made the sawing process possible here at Moss Sawmill. It takes around 40 individuals on both shifts to maintain and run the mill to its full potential, and many others behind the scenes to do the administrative duties. Over the years hundreds of employees have supported their families with sawmills the Smith family has operated, and thousands more have benefited from the products they have produced over the years. Moss Sawmill has been a great asset to the community for close to fifty years and we all hope to continue this tradition for many more years to come.
– by Joey Dyer, Moss Sawmills and GF Hardwoods