8 Tips for Milling Rough Lumber
Get the best yield from the least-expensive wood.
by Tom Caspar
Cut Big Boards into Small Pieces
You might think the best strategy for milling rough lumber is to flatten as large a piece as possible, then cut it into smaller parts. Not true. It’s better to cut a big roughsawn board into individual pieces, one for each part on your cutting list, more or less, and then start milling. The problem with the big-board strategy is that the smaller pieces you cut from it may not end up flat or straight. Some boards have a lot of internal stress built up inside. When the board is whole, all this stress is in balance. When you rip the board, you release some of that stress. Each half seeks a new balance and a new shape. A flat, straight board ripped down the middle might well make two boards that aren’t flat or straight. It’s hard to predict which boards will react this way, so I assume every board could present this problem.
I always cut my individual pieces slightly oversize, adding 1/2 in. of length and 1/4 in. of width.
Use the Best Crosscutting Tools
Rough lumber can be tricky to crosscut safely. Its faces and edges are rarely flat and straight, so using a chop saw, miter saw or tablesaw is not the best practice, because the blade could bind, stall or kick back.
My favorite tools for crosscutting are a jigsaw, a circular saw and a Japanese tree-trimming saw (see Source, below). This very coarse handsaw cuts incredibly fast, even through thick hardwoods.
I generally crosscut before doing any jointing or planing. Crosscutting reduces a big board to more manageable sizes, so I can mill more accurately. I put my board on four sawhorses for plenty of support and mark it with chalk, a felt-tip pen or a carpenter’s soft-leaded pencil.
Let Boards Rest
To make pieces dead flat, I usually let boards rest before taking them down to final thickness. I plane boards 1/8 in. thicker than needed and stack them with stickers or stand them on edge so air can circulate around every side.
After the boards rest for a day or so, I check each board for flatness by laying it on my tablesaw or jointer. It’s not unusual to find that some previously flat boards have cupped or twisted a bit. I rejoint one side of these boards, then plane every board to final thickness.
Avoid Badly Twisted Boards
Some twisted boards are hopeless causes. You might just as well turn them into firewood. Sure, you can joint them flat, but a few rogue boards have a nasty habit of slowly continuing to twist, no matter how many times they’re jointed or how short or narrow you cut them.
If your rough lumber is only slightly twisted, however, don’t get too alarmed. It doesn’t mean you’ve got junk wood. It may remain perfectly stable after it’s milled. Just cut it as short and narrow as you can in the rough state—but not less than 12 in. long—to get the m...
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