Easy Arcs

Here's a tip for marking large arcs.

Instead of using a beam compass, or a nail, string, and pencil, use a thin piece of stock or rip a thin strip. I like to keep thin strips ripped from 8-foot stock because I design many projects that call for 2 1/4-inch parts. Once a 1 x 3 (which measures 2 1/2 inches wide) is ripped to 2 1/4 inches I'm left with a 1/8-inch strip. (This will vary depending on the kerf of your table saw blade). Keeping 8-foot lengths of these strips gives me plenty to work with in nearly any size arc I might need. And of course, I cut some of them shorter – 8 feet gets a bit unwieldy.

I mark my end points and the peak of the arc on the workpiece. Then I drive brads near these points (allowing for the strip and pencil thicknesses). I fit the strip against the end points, then "bow" the strip to reach the arc peak. Then I simply use the strip as my guide for marking the arc.

I make sure to apply even pressure on the strip at the arc peak, and I don't put any additional pressure on the strip when I make the mark. Sometimes I’ll add a third brad at the arc peak to hold the strip steady.

If you don’t want the brad holes on your workpiece, place the part on a large piece of scrap plywood and drive the brads into the scrap instead of the workpiece. You’ll need to make several adjustments to get the positioning right. If you’re handy enough, I’ve bet you’ve already figured out that you could make jigs out of scrap material to accomplish the same thing.

It will take some practice, but it creates a quick arc when you've got the hang of it. Then all you have to do is have a steady hand when cutting the arc.

Screws vs. Nails

You may have debated at times which fastener to use during assembly of a project. You’ll get just as many opinions as woodworkers you ask, but generally you can follow these guidelines.

Use screws for:

• a lot of holding power in a high-stress connection.

• fastening hardwoods that tend to split, or that would bend a nail.

• when the “purchase” of the fastener is limited to a short depth, as in stock that’s too thin to hold a nail with sufficient strength.

• a project you want to disassemble later (don’t forget to NOT use glue).

• when the screw heads serve as a visual element in the design.

• a project that involves fine craftsmanship, including recessed fasteners covered by wood plugs.

Use nails for:

• when you need to work fast, especially when power-nailing with a pneumatic nail gun is an option.

• fastening soft or semi-hard woods that “give” sufficiently to accept a nail without splitting.

• using common construction or carpentry techniques such as rough framing, attaching plywood sheathing, and so on. (Subflooring installation is an exception, as nails can cause squeaking.)

• keeping project costs as low as possible.

• attaching molding and other finish trim where a small fastener head is desired.

• when hammer dents in the material won’t detract from the project.