The pencil is a very useful tool to have in the workshop. While it does a commendable job for rough marking and for making orientation and cutting guidelines, it is not the best choice when laying out precision cut lines for highly visible joints, such as dovetails, box joints, butterfly keys, and exposed tenons. For these kinds of joints you would do well to use a precision marking knife.
There are a number of marking knives on the market. The one that I have been using over the past several months is hand-made by Dave Jeske of Blue Spruce Toolworks.
The Blue Spruce marking knife is an exceptional tool. It’s well designed and superbly made. The tool fits the hand like a high quality writing instrument and scores a precise, clean line with minimal effort. At 6 ⅜” long and only .670″ diameter, it fits easily into a shop apron. The nicely shaped handle is cocobolo. The business end of the knife is a spear shaped blade, .03″ thick, ¼” wide, and 1″ long, held in place by two brass ferrules. The tip of the blade has a 65º angle, while the blade bevel is 30º.
The marking knife is very easy to use. It’s bevelled on one side only to fit flat against a straight edge and can be used either right or left handed. I found it more efficient to tilt the knife so that it’s cutting at about a 45º angle with the tip of the blade. Take a look at the difference in thickness between the pencil line and the line cut by the Blue Spruce (see photo). Notice how clean and crisp the knife line is, compared to the pencil line.
The marking knife cuts the wood fibers, providing a micro channel that your chisel or saw can register against. You can actually feel the chisel settle into the scored line made by the marking knife, and the resulting impression will be right on the mark. This same principle works the same way when you saw a scored line – the saw doesn’t start the cut, the marking knife does; the saw follows the scored line. If you cut a lot of dovetails you’ll really like the thin blade on the Blue Spruce. It’ll fit easily between the tightest tails you can cut.
The Blue Spruce came sharp and ready to use. I would imagine that at some time it will have to be honed again – but only after quite a few miles of marking. No problem though. Even though the bevels are pretty narrow, if you take your time you can hone them on a waterstone. I tried it using slow, steady strokes and it honed beautifully.
The Blue Spruce marking knife did a very good job of scoring across end grain. However for those of you who prefer a scratch awl for this job, Dave makes a lovely one. It has a 4 ¼” cocobolo handle and a 2″ blade. I like a finer point on the end of the awl; a judicial application of fine sandpaper did the trick.
Pricing is very reasonable on these tools: approx $49CDN for the small marking knife ($67CDN for a larger version); $43CDN for the awl, or $85CDN for both. There is no doubt that using finely crafted hand tools makes woodworking even more enjoyable than it already is. According to Jeske, Blue Spruce Toolworks was founded “to provide high quality hand tools to the discerning craftsman who appreciates using a finely crafted tool”.
Right on the mark Dave!