Introduction: Making Thin Wood Boards for Laser Cutting
Thin plywood sheets are a favorite material for laser cutting. They are sturdy, dimensionally stable, and easily available in different thicknesses. But with thin plywood boards you are mostly limited to birch - no nice cherry, walnut, oak, maple, etc. And the laser-cut edges never look good even when you sand off the burned part.
So I prepare my own thin wood boards for laser cutting; and I’ll show you how to cut (resaw) them safely on a table saw to 1/4”, 1/8”, or even less thickness. I have made hardwood boards from maple, cherry, and walnut as thin as 1/16". Its not plywood; but if you laminate two or more layers after laser cutting you will have a strong final piece.
Of course you could take a hardwood board and plane it down to your desired thickness; but I think that’s a lot of waste. By resawing a 3/4" thick board I can get at least three thin boards for my projects.
3/4 inch or thicker hardwood board
Table Saw, Sander, Planer (optional)
Step 1: Straighten the Edges
Let's take a 5 inch wide hardwood board 3/4 inch thick, and let’s make it 12 to 20 inches long, whatever fits into your laser cutter. Make sure the board is not warped, cupped, or twisted. The surfaces should be planed and sanded smooth. Cut off any checks or splits on the ends of the board. Make a rip cut along the two long edges to have them clean and straight. If you have a jointer planer, use it.
Step 2: First Cut
For these cuts I use a thin kerf ripping blade with good results. Raise the table saw blade to slightly more than half the width of the board. Make sure the blade is perpendicular to the table saw top. Set the fence to 1/8” from the blade. Stand the board on edge and make the cut as shown. It is essential to use a feather-board to hold the work piece against the fence ahead of the blade. Be sure to use the table saw riving knife. I use a second feather-board past the blade for better control, but I mount it with very little pressure against the wood to avoid pinching the blade. Never use a feather-board against the blade!
Go slow when making the cut as the table saw will be working really hard.
If you want to cut a board thinner than 1/8” I highly recommend to use a waste board clamped against the fence.
By the way, I made my own 3d printed feather-board in this Instructable.
Step 3: Second Cut
The second cut is made by flipping the board end-over-end, putting the same side against the fence as in the first cut. This cut will separate the board, so be very careful near the end of the cut. Use a push stick like the one shown, it can be easily made from a scrap piece of 2 by 4 lumber. The push stick is 9 inches long, the heel is 1/2 inch deep.
Step 4: Third and Fourth Cut
Put the first 1/8" thick board aside. With the remaining board repeat the two cuts, putting the remaining good surface against the fence.
You will have two boards 1/8” thick and the center board of some thickness.
Step 5: Finish the Surfaces
None of the four sawed faces will be perfect; plane and/or sand them to remove any tool marks. From the 3/4 inch thick original board I got two 1/8 inch thick boards and one 3/16 inch thick board ready for the laser cutter.
Step 6: How to Cut Wider Boards
Most 10” table saw blades will rise to about 3.5 inches. At that height the cuts can be a little dicey. If you need to resaw a board wider than 6 inches make two cuts of 3 inches (blade height) as before, then cut down through the middle on a bandsaw or with a handsaw. It works pretty well. Finish the surfaces as before.
Step 7: Using the Hardwood Boards
When you have your thin hardwood board you can laser-cut your design. I use blue painter’s tape both top and bottom to keep the surfaces clean from smoke stains and pitch deposits. After cutting, peel off the tape, do a light sanding, and you are good. If necessary laminate pieces together for additional strength, crossing the grain direction if possible.
Since you are using solid hardwood you can sand the burned laser-cut edges to bring back your beautiful hardwood. A few examples are included.
I made some toys with cherry wood, two and four layers laminated for strength. Look at the pictures and check out my Instructable “Toy Workbench With Lots of Wooden Tools”.