Saturday, May 19, 2007

Scrub Planes

As with many cabinetmakers, I followed my interest in handtools to handplanes and planemaking. Handplanes have come to represent "fine craftsmanship", hence their presence in magazines, catalogues and logos. Any visit to a handtool forum and you will find that much of the conversation revolves around planes. It is a great introduction to cutting wood with a fixed blade and sharpening etc...but there are other tools that offer greater freedom awaiting. I still flatten and joint my seat blanks with a handplane, which teaches me a great deal about the hunk of wood that I will be carving, there is great satisfaction to be had in practicing this skill, but I try to remember that the handplane is a means to an end and not an end in itself.
If you have a 20" jointer and planer, you can ignore this! The scrub plane is the first plane used to flatten the surface of a board. It is fitting that this post follows the one about inshaves having too curved a blade, because it is the curve of the blade that distinguishes the scrub plane and makes it work. The curved blade reduces the width of the cut taken and ensures that the edge of the shavings are tapered which reduces tearout while enabling a heavy cut. If you tried to plane "with" the grain and find yourself going the wrong way, the tearout could be dramatic. By using the blade crossgrain, the fibers being sheared are always supported by the fiber next to them, this gives a reasonably clean cut, which is fine for this early stage of flattening.
The scrub plane is not truly "essential" to flattening a board. The same results can be achieved with a regular plane, just more slowly and with more effort. But the speed gained and ease of creating a scrub plane makes it a good plane to start your collection. The photo shows three different scrub planes. The plane in the foreground is a Lie-Nielson scrub plane, its quality construction is reflected in its price. In the middle is a plane that I made myself and in the back is an old wooden jack plane with a reground blade. Below you can see the shape that I find best for my scrub blades. If you are considering acquiring a scrub plane, I'd encourage you to seek out an old wooden smoother or metal plane and simply reground the blade. That's it. It is simple and cheap and will give the satisfaction of using a tool that you have "made" yourself. All that is required is the rounded blade, a wide throat opening and to set the chipbreaker back from the edge. There is lots of good info on planing technique available at the woodworking forums posted on the right. Good luck

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