How to Mill Rough Lumber
I usually mill my own stock, 50 to 100 board feet of rough lumber at a time. The process begins with my trip to the lumberyard. I take the time to pick stock that has the least cup, bow and twist. My strategy is not to completely avoid all defects, as that would be too costly. Instead, I work with deformed stock that my shop set-up can handle efficiently.
It is good advice to mill only the stock that you need for a project. The trade-off, however, is reduced efficiency, as you have to repeat the machine set-up for every small milling job. I prefer to mill my rough lumber in bulk, preparing enough for several projects.
For edge-jointing, I use my table saw. The only other machine I need to mill my wood is a thickness planer.
No Jointer? No Problem
Flattening boards wider than 6” or 8” is quite a challenge unless you own one of those 12” wide jointers. For hobbyists with limited budget and space, a wiser choice is to invest in a well-built 12-1/2” or 13” bench-top thickness planer and use it both for flattening and planing to thickness.
First, I sort all the boards into groups according to their rough thickness (boards that are too long can be crosscut to more manageable lengths) and condition (twisted, bowed or cupped). By milling boards of similar thickness and condition as a group, you have to make fewer machine adjustments.
When it comes to defective lumber, twisted boards are the more difficult ones to handle. Mildly cupped boards, for example, can usually be dressed using the thickness planer alone. Place the board concave face/cupped-side (usually the bark side) down so it does not rock on the planer’s bed. Twisted lumber, however, is a challenge whether using a jointer or a thickness planer because it rocks as you feed it into the machine.
The trick is to stabilize a twisted board with an aid before you flatten it. One such example is the simple planing sled, made of a flat, rigid sheet good with a top cleat attached to one end. This sled supports a warped board with shims under the high spots. More sophisticated sleds can be designed and built that allow you to back up a board with adjustable supports instead of shims.
Left: The author’s planing sleds, about 12” wide and of various lengths, can handle warped lumber up to 6’ long.
Right: This planer sled uses rows of support blocks that can be raised or lowered to level the lumber. (Photo by Kelly Miciak)
To use the planing sled, butt the twisted board against the cleat in the proper grain direction and place shims to fit underneath the gaps. Next place the sled, cleat end first, on the infeed table and feed the whole sled through the planer. The cleat will keep the infeed rollers from pushing the stock ahead of the sled.
Left: Squeeze blobs of hot-melt glue to attach the shims to both the board and the sled.
Right: Once the glue sets, run the sled (with the board) through the planer.
I take multiple light passes, removing no more than 1/16” each time. My final passes are set at 1/32” or less. After one face is milled, remove the board from the sled. Turn the board over and continue milling the second face.
In shops with extreme humidity swings, leave excess wood to allow final milling in case some warping sets in after leaving the boards to rest for a couple of days.
Left: After flattening the first face, remove the board from the sled and mill the opposite face.
Right: Try to take off an equal amount of stock from each face to minimize warping when the tension is released.
Overbites? My Remedies
Snipe (scoop-like depression) occurs when the workpiece is not properly supported as it is fed through the planer. Not all machines are made the same, and I recommend investing in a thickness planer that has a carriage lock feature for better snipe control.
The simplest snipe solution, but one that is also wasteful, is to let the snipe happen and then cut off the ends. When using this method, wait to cut off any rough or checked ends until the board is planed.
Left: Look for the carriage lock feature when you consider buying a bench-top planer.
Right: Cut off the rough ends with any snipe after the faces are dimensioned.
In my shop, I also try to minimize snipe by using the following measures:
- Set the Infeed/Outfeed Tables Higher
Using test cuts until the snipe is minimal, set the leading edge of the infeed table and the trailing edge of the outfeed table higher than the planer’s bed.
It may also help to keep the ends from teetering up into the cutter blades by lifting the back end of the board as you run it through the planer and lifting the front end just as the board is about to leave the planer.
The infeed and outfeed tables are set slightly higher than the planer’s bed.
- Feed the Boards Through at a Slight Angle
Feed a long board through the planer at an angle so the cutter head makes contact with just the corners of the board.
Skewing the workpiece at 15° to 20° limits the snipe to the leading and trailing corners.
- Gang-Feed the Workpiece with a Scrap
Butt boards end-to-end as you feed them through the planer using a sacrificial board (about 14” long) of the same thickness as the workpiece at the beginning and end.
You’ll find snipe on the sacrificial board only.
With a planer and a simple planing jig, you can mill your own stock and reap the rewards of using rough lumber, one of which is the pride of completing a project from rough to finished. Add some pride to your next project!
Text and photos by Charles Mak
Charles Mak, now in retirement, is an enthusiastic hobby woodworker, teacher, writer and tipster. He formerly worked part-time at his local Lee Valley Tools store.
Further Reading
Mak, Charles. “Machining Difficult Timbers”. Australian Wood Review. June 2015. Pp. 96-98.
Rust, Keith. “Flatten Boards Without a Jointer”. Fine Woodworking. Jan./Feb. 2005. Pp. 58-61.
