Popular Woodworking 2007-06 № 162, страница 53

With a standard Bailey-style bench plane (above left), the frog contacts the body in a few key places. With a Bed Rock plane (above right), the sole and body of the plane are both machined flat for maximum contact.

The iron of a jack plane (on top) has a gentle curve, while the iron of a scrub plane (below) has a curved cutting edge that has a pronounced arc.

or <'

"

K£

is ground straight across. This is the appropriate shape for use on a wooden surface that is more narrow than the blade is wide. In other words, this is the edge you want on your j ointer plane.

However, the same shape will not work on a surface that is wider than the cutter. This means that your smooth plane and a jack plane that is used on the wide face of a board cannot be ground straight. Imagine the result. The blade would leave behind a square-edged trough the shape of the cutter. This would not be at all acceptable on a visible surface. Instead, the cutting edges on a smooth plane and a jack have to

be crested (as shown above). This way, they each remove a chip that is slightly thicker in the center, but that tapers out to nothing on the edges.

How much a cutting edge should be crested also depends on the plane's purpose. A jack plane is used for heavy stock removal. For example, if you are starting with a rough-sawn board, a jack will quickly remove all the saw marks and expose fresh wood. A jack plane blade needs to be aggressive and so its cresting is pronounced.

A smooth plane is used to bring a surface close to its final stage, nearly ready for applying

the finish. A surface that is hand-planed will have a gentle texture that, depending on your sensibilities, you can leave or easily sand away. The appropriate amount of cresting on a smooth plane blade is almost imperceptible.

Scrub Planes v. Jack Planes

The crested blade on a jack plane causes many people to confuse this tool with a scrub plane. They are quite different. A scrub plane is a continental European plane designed to flatten boards. At a time in history when all the lumber that came into a woodworking shop was rough sawn and air dried, each board first had to be made flat and have the sawn surface removed. The scrub plane was the tool that started this process. Its blade has a cutting edge that is close to a semicircle. The plane is pushed quickly and forcefully across the surface of the board at a slight angle. If the board is warped or wracked, it catches the high spots and very quickly knocks them down. After the scrub plane has flattened the

board, the woodworker is ready to advance to the jack plane.

In English and American shops this preparatory work was done with a jack plane. Although the cresting of a jack's cutter is extreme relative to a smooth plane, it does not even approach that of the scrub.

Preparing for Use

Whether you have a new plane or an older one, you will want to do some steps to get it ready for use. A bit of judgment is needed to determine just how much tuning you want to do. For me, it is a function of the plane's purpose. My jack plane is mostly used for prepping rough-sawn lumber while my best No. 604 Bed Rock smooth plane is reserved for figured wood and working around knots. Obviously, far more work has been invested in the smooth plane than in my jack. Still, my jack has not been ignored; it's just not been pampered as much.

We have discussed the importance of the sole. Your plane will work better if the sole is flattened. You will be surprised at how irregular many plane soles are, even when the tool is brand new.

The most important place for a sole to be flat is in front of the mouth, as that is the area that holds the chip down. This is unfortunately the area that receives the most wear, and a plane that has been used a lot will frequently need work in this area.

Some people take planes to a machine shop to have their soles ground flat. I think this is extreme. Remember - a hand-plane is a woodworking tool and does not require precision to four decimal places. You can get the maximum performance out of your plane without it ever leaving your shop.

I flatten on a V2"-thick aluminum plate with a long strip of

popularwoodworking.com

23