Sawing Logs Into Lumber

The Northeastern Woodworkers Association has many special interest groups: some turn bowls, others craft toys, whittle birds, make furniture, create banjos and mill lumber. Their latest newsletter has a more complete list: (http://woodworker.org/nl/oct15.pdf). To support a wood craft education fund, one group annually auctions a large variety of seasoned native lumber that they produce. This wood is milled either from single donated logs or large woodlots with many varieties. I joined the team last week and thoroughly enjoyed learning how a sawyer turns logs into boards. 

Sawyer Setting Up the Sawmill Bed

The Bandsaw, Its Engine, and the Alternator Used to Power the Motors and Hydraulics

The Complete Portable Sawmill

We volunteers wrestled logs to the sawmill, discarded unusable slices cut off logs, and stacked the good lumber on trailers. Three volunteers came in pickups with substantial trailers they used to carry the few tons of new lumber to the Shaker barn. This very old building has a wing where fresh lumber is stacked, each piece separated from the others by "stickers", narrow boards made to optimize air flow, so lumber can dry naturally for two years. The sawyer studies each log for a few minutes to ascertain the best orientation to make the first cut. He then brings the reference side to the top and levels the center of the log by raising the smaller end. Since the bandsaw blade is horizontal, every cut removes a layer off the top of the log. The first slice on every side has one side flat on the bottom with the rest as round as the tree trunk. His objective for these slices that make the round log ever more rectangular is to create flat sides wide enough to make single pieces of useable lumber. Once the log is rectangular, without any bark showing, he cuts the entire width into boards.

The First Cut, With the Flat Bottom Wide Enough to Make Lumber (Note the Sawmill's Name at the Bottom of the Photo)

The Second Cut, With the First Cut Pressed Against Stops That Are Perpendicular to the Bandsaw Blade

The Third Cut Makes a Slice of Lumber That Has Rough Edges and Bark on Both Sides. These are Stacked Off to the Side for Later Processing.

Making the Third Side Flat

Cutting the First Slice Off the Fourth Side

Offcuts That Have Rough Sides

Getting Ready to Make Square Edges on the First Side

This portable sawmill is quite advanced, with controls mounted in front of a seat that travels with the saw. Though the slices have to be handled manually, all manipulation of the heavy log is done by hydraulic pistons that the operator manipulates while seated. Less sophisticated units require the operator to walk along as the saw cuts, logs have to be wrestled into place, manually adjusted and clamped.

View Showing the Sawyer Riding Along with the Saw. Sawdust Is Transported Out the Black Tube on the Left Onto the Ground. The Red Tank Above the Saw Holds Gasoline, the White Tank Has a Soap/Water Solution for Keeping the Bandsaw Blade Free of Sap.

Close-up of Sawyer, the Windrow of Sawdust, and the Stump of One of the Red Oak Trees We Made into Lumber.

The Discard Pile Where We Threw the Pieces that Had Rough Edges

The Bandsaw Blade

The Third and Last Trailer Load of Wood to be Transported to the Drying Barn. This Load Is Primarily 5/4 (1.25 Inch) Thick Red Oak Planks.

The group hires a sawyer who brings his portable sawmill. He gets paid by the board-foot of lumber we make. A board foot is a square foot of lumber that is one inch thick. Most of the 1,200 board feet of lumber we made was 4/4, or one inch thick, though we also made some 3/4, 5/4 and 8/4 (2 inch) pieces. One of my jobs was to measure and record each board as it came off the mill, one page for each log. All our logs were nominally eight feet long, with eight to ten inches extra on each end to allow removal of split ends when this rough-cut lumber is planed after drying for two years. The largest log made over 200 board feet, with the rest between 100 and 200. Altogether, we made over 1,200 board feet in a day that was interrupted by a smoking alternator belt that had to be replaced. It took two hours to obtain the new belt and install it.

The sawyer had to stop cutting two times in order to exchange a dull blade with one he had resharpened. This process took only 20 minutes. The sawmill is an hydraulic Wood-Mizer, Model LT40-H, that the sawyer has used for over a decade. The unit uses a gasoline engine to power both an alternator and the bandsaw that cuts the wood. The alternator charges a battery that powers quite a few motors and a hydraulic pump that operates six functions: log feeding, two opposing log clamp systems, log rotation, and near/far log leveling.