Thursday, July 29, 2010

What Can I Do With All This Scrap Wood?

There are almost as many right answers to this question as there are woodworkers. The solution really depends on the kind of projects you typically build, the various wood species involved, and the quantities and sizes of scrap generated. Let’s run down some options:

• First, improve your storage for any scrap stock you might want to keep. Organizing it by size or species, even if it’s just sitting in a bunch of 5-gallon buckets, will make it more likely you’ll use it later rather than cut fresh boards up for small parts. Or try our wood organizer project: http://www.lowescreativeideas.com/idea-library/projects/Wood_Organizer_0609.aspx

• For pricey hardwoods, especially any exotics, design some small-scale gift projects where this stock can serve as parts or accents. Jewelry or keepsake boxes, hand mirrors, or custom cutting boards can be adorned with inlays or built entirely of scrap hardwood.

• Find a local school shop and donate it for student use. Aspiring young woodworkers often have a lot of enthusiasm and energy but not much money to buy materials; you can support their craft and help keep good lumber from going to waste in a landfill.

• If you have children at home, offer them material to design and build their own small projects. Of course you’ll have to supervise their time in the shop, but a lot of kids love the hands-on fun of woodworking.

• Except for pressure-treated lumber or resinous woods such as pine or fir, you can use scrap stock as kindling in a fireplace or woodstove. If you do this every winter, odds are you won’t accumulate more than a few boxes full of scrap each year.

Thursday, July 22, 2010

Water-base Vs. Oil-Base Stains

Water-based wood stains share many of the same virtues of latex paints and other water-based wood finishes: low odor, easy clean-up without harsh solvents, and relatively fast drying. You’ll also find a wider range of color choices that includes not only wood tones but also blue, green, red, and yellow. If you are following up with a water-based clear polyurethane or similar topcoat finish, the compatibility of the two products also helps. With some of those properties, however, come a few drawbacks. First, the water swells and raises the wood grain at the surface, creating a rougher texture that may have to be re-sanded. Also, water-based stains tend to set the color (pigment) faster; you have to keep working a wet edge and wipe off the excess stain immediately so you don’t get lap marks. On big surfaces, that pace can be difficult to manage unless you have a helper. Or use a gel-type water-based stain, which can give you more working time.

Traditional oil-based wood stains often have the same type of pigment, but the oil layer keeps the particles in suspension longer and affords you more time to apply the stain and wipe down the wood surface without getting lap marks or streaks. But the solvent fumes (from the volatile organic compounds, or VOC) require good ventilation and are environmentally harmful. Drying time is slower, because although the solvents evaporate quickly the oil still has to cure through exposure to oxygen. That often means waiting 24 hours to apply a clear topcoat, especially a water-based finish. Oil-based stains and finishes tend to yield an amber or yellowish tone that increases with age, great for the warm look of traditional furniture, but for some contemporary designs the neutral or clear look of water-based stains and finishes is a better choice.

With either category of product, it’s always best to experiment on some scrap stock leftover from your project. Each combination of stain and clear finish will produce a slightly different look; try out a few options so you don’t get an unwelcome surprise on your project.

Thursday, July 15, 2010

Using a router to cut dadoes and rabbets

The most basic kinds of woodworking can happen with little more than a handsaw, hammer, nails, and glue, but the core of the craft is joinery. Making specialized cuts and contours in wood surfaces lets you join parts more accurately and create a much stronger result, but it takes more tools and techniques to step up to that level. Traditional hand tools still get the job done, though they require an investment of time and skills that isn’t an option for every woodworker today.

Outfitting your shop with a table saw will, in one step, bring a new dimension of versatility and accuracy to your woodworking efforts, and it’s probably the best first investment in power machinery. But don’t overlook portable power tools, especially routers. These small powerhouses spin a wide range of interchangeable cutters (called bits) at high speeds, letting you mill decorative edges as well as cut precise joinery such as rabbets, dadoes, and dovetails.

Cross-grain dadoes can be cut by aligning a jig or straightedge guide with your layout marking and clamping it in place. A dado is nothing more than a flat-bottom groove machined to accept another part, such as a shelf or a stiffening brace. Straight-cut router bits are sold in common fractional widths (1/4, 1/2, 3/4-inch, and so on) and so with a single pass can cut shallow and precise dadoes; for deeper or wider dadoes, you can make multiple passes.

The particular mechanics of a router cut mean that tearout and splintering are often far less problematic than when making a similar cut with a circular saw blade. Better still, the bottom face of the groove is smooth and flat, resulting in a better glue bond when you fit a mating part into place. But this technique illustrates one of the common requirements of router use: having a guide board, jig, or template to control the router base so the cutter doesn’t drift randomly off-course.

Some router bits feature built-in guide bearings that ride against the edge of a workpiece and cut away a portion of that edge. Many of these are decorative bits that cut curved profiles, but a rabbeting bit is different. A rabbet is an L-shape notch cut along the edge of a workpiece, again to make room for another part that will nest there. The size can be varied by using different bit and bearing diameters, and the depth adjustment is provided via the router base; typically the cut is made in several lighter passes rather than one heavy cut. This produces less strain on the cutter and the router motor, and typically yields a cleaner cut on the workpiece.

The same straight cutters used for dadoes can also cut rabbets, but an edge guide or other accessory must be used to control the cutter path so it cuts straight along the edge as desired.

Thursday, July 8, 2010

Cutting Miters and Bevels

Thanks to the versatility of table saws and power miter saws, making angled cuts requires only making some simple adjustments, not switching to another specialized tool or machine. That said, the cutting dynamics do change some when the blade or workpiece angle varies from a basic 90-degree cut, and this requires some different techniques.

When you’re making a standard rip cut or crosscut, you’re feeding the workpiece against the cutting teeth (or vice versa) with direct support to counteract and help control the cutting force generated by the spinning blade. Otherwise, that force would launch the workpiece like a projectile rather than cut through it. Angled settings add the likelihood of deflection because support of the workpiece isn’t as directly opposed to the cutting pressure. Working safely and accurately involves making sure the workpiece doesn’t shift out of alignment during the cut, and techniques for accomplishing that depend on the tool you’re using.

Table saw

Angled crosscuts on the table saw typically require using the miter gauge. The sharper the angle, the more the workpiece will want to slide against the face of the miter gauge. The most reliable ways to prevent this are to apply adhesive-backed sandpaper to the miter gauge face, attach a sacrificial backer board to the miter gauge and fit it with a stop block, or clamp the workpiece to the miter gauge if the tool’s design allows it. Better still, make a shop-built crosscut “sled” with an adjustable angle guide. Any of these measures is usually enough to prevent the “creep” that can occur when making a miter cut or a compound angle (bevel and miter together) on the table saw. Incidentally, don’t trust the accuracy of the angle scales on the saw or miter gauge—make a trial cut and check it.

Beveled rip cuts introduce another key consideration—keeping the workpiece flat on the table. Most table saw blades tilt to the right, toward the rip fence, creating the possibility that the workpiece might bind during the cut. Applying pressure to keep the stock flat on the table helps reduce the chances of binding and/or burning the edge, but take extra care to keep your fingers clear of the blade. When possible, consider repositioning the rip fence to the left side of the table, so the blade tilts away from the fence, the workpiece, and your hands.

Circular saw

Using a handheld circular saw for angled cuts requires the same techniques and accessory guides you’d normally use. For simple miter cuts, you can use an angle square or a shop-built jig as a guide; clamp the guide to the workpiece so you can keep your fingers a safe distance from the blade. For beveled cuts, use the adjustment feature on the saw’s base, but again, don’t trust the scale; make a trial cut and check it. Remember that the maximum cutting depth decreases as the angle increases.

Miter saw

Miter saws are designed to excel at angled cuts, so they don’t really require specialized techniques or accessories. The center table pivots for miter cuts, and on compound miter saws, the motor assembly swivels down to make bevel cuts also. One factor is especially critical: first, make certain the workpiece is held securely against the table and fence. You can do this with hand pressure or with a clamp; many saws feature a removable clamp standard or as an optional accessory. Steeply angled cuts, especially compound angle cuts, can bring the blade dangerously close to your fingers if you are holding the stock manually. In that case, secure the workpiece with clamps instead.