Make the Most of Your Materials
Sheet goods: Size defines design
48×96". Those are the magic numbers when working with most sheet goods. The exceptions: medium-density fiberboard (MDF), usually 1" longer in each dimension to allow for saw kerfs; and Baltic birch plywood, which often comes in 60×60" sheets. Plywood’s consistent size and absence of surface blemishes make it easy to plan your exact materials needs at the design stage. Here’s how you can save money by reducing the number of sheets in your project:
1. Cost-cutting starts with a cutting diagram. Whether you sketch it on a pad, model it on the computer, or cut out scale mock-ups, as shown below, a cutting diagram helps you optimize the use of any sheet goods as you design your project.
Start by laying out the largest pieces and filling in with smaller pieces, making sure to add 1⁄8 " to account for saw kerfs. Where possible, group pieces of like length and width. This minimizes the number of cuts needed to break down the sheet. It may take several arrangements to find the fit that maximizes yield.
2. Cheat to stretch your sheets. Next, recheck your design. Can you eliminate a sheet by altering part dimensions? If so, you’ve saved a lot of money before making the first cut.
For example, eliminate a cabinet’s toekick in favor of a 4" hardwood base, as shown in the example at below. This shortens the standard cabinet-side height from 34 1⁄2 " to 31", netting six cabinet sides from a single sheet of plywood rather than the normal four—a gain of 50 percent!
And expanding television sizes don’t have to expand your materials bill. Adding a divider to the back of a 50"-wide entertainment cabinet, as shown below stretches the plywood to get the full width of the cabinet from a single sheet.
3. Thriftiness and sneakiness go hand in hand. Don’t use up expensive hardwood plywood on furniture parts that will rarely be seen. In the barrister’s bookcase below, using inexpensive birch plywood on the case bottom and top kept the amount of walnut-veneered plywood to less than a half sheet.
Even if you have to orient the grain the wrong direction to make a scrap piece of plywood fit in a hidden area, don’t sweat it. Because plywood consists of multiple plies with alternating grain directions, it won’t compromise the structural integrity of the piece. And no one will be the wiser.
Solid woods: No two boards alike
Unlike sheet goods, solid woods don’t come in predictable sizes; irregularity is the norm. Therefore, using the material efficiently becomes an exercise in working around size variations, blemishes (such as knots and sapwood), and warped wood.
1. Shop for parts, not board feet. A materials list, like the ones at the ends of project articles in this magazine, helps you focus your search for boards that are good matches for your project parts—just don’t get too hung up on finding a magic board that fits all of your project parts like a completed jigsaw puzzle. Instead look for consistent coloring and grain pattern for each individual part.
At first it seems counterintuitive in the name of efficiency to buy more wood than your plans call for. But you’ll end up using much of it in short order, averting the need to buy fresh poplar for secondary project parts or maple for shop jigs. In effect you’ll reap the savings from your scrap bin. And your project benefits from using the best-looking parts of each board.
Once you get used to shopping selectively, start looking in your lumber dealer’s lower-grade bins. You won’t get as much wide, clear yield as found in the Firsts and Seconds (FAS) grade, but you’ll usually save enough money buying No. 1 or No. 2 Common boards to more than make up for the lower yields, below.
2. Don’t reject the defects. Take a closer look at that sapwood-streaked board in your reject pile, below. Does the sapwood go all the way through the piece? A simple board flip might hide it for a spectacular save. The same holds true for knots.
In both cases look for opportunities to minimize their appearances when machining the wood. You may be able to surface away the defective side during thicknessing, even if that means using wood slightly thinner than your plans call for. No one will notice if your face frame measures a hair shy of 3⁄4 " or the jewelry-box sides are slightly under 1⁄2 ". Just be sure to account for the size difference when machining the joinery.
Also keep in mind that a project built with defect-free lumber can lack character. Strategically placing voids, sapwood, live edges, and knots, as shown below, can enhance a project’s aesthetics and take it from being everyday furniture to a stunning work of art.
3. Turn bad boards into good wood. Even when you shop carefully, lumber that started out straight and true at your local hardwood retailer doesn’t always stay that way in your shop. All is not lost, however; salvageable wood hides in those boards. Follow the steps below to rescue wood from the most commonly encountered warps.
Bow: Don’t sweat slight bows where they can be pulled straight by fasteners, such as screws or biscuits. Treat more substantial bows by crosscutting into shorter pieces, as shown, and resurfacing as necessary.
Crook: For minor crooks, first joint the concave edge flat, and then rip the opposite edge parallel. For boards too long to handle on the jointer, first snap a chalk line along one edge, cut along the line with a circular saw, and then joint and rip to width. Whenever possible, crosscut boards with severe crooks into shorter pieces, as shown, before jointing and ripping.
Cup: Joint the concave face of a slightly cupped board, creating a flat face. Planing then leaves you with a slightly thinner board. Or rip a more severely cupped board into strips. (Rip with the concave side up to avoid kickback.) Then flip the center piece to invert the cupping, edge-glue them back together, and joint and plane the panel.
Twist: For short twisted boards, joint, applying pressure on the low corners until you’ve established a flat reference surface. Then flatten with the planer. Severe twists require you to machine the board into shorter and narrower pieces for secondary parts, as shown.