Popular Woodworking 2009-10 № 178, страница 36
tear-out. This is where the benefits of the toothed blade begin to show. You can plane in any direction, regardless of grain direction or structure. Very quickly you will render the board flat. Then you will be able to clean up the tooth marks with surprisingly little effort, leaving a beautiful smooth surface. Even if you are doing all your roughing with machines (such as a power jointer and power planer) you will still find a use for the toothed blade. Invariably when you process figured wood you end up with chip-out in the surface of the board where the grain acts up. These problem areas can be very difficult to clean up with a normal blade arrangement. You end up having to take very fine shavings to avoid tear-out and it takes a long time to get rid of the problem without causing more damage. The toothed blade allows you to remove material very quickly without causing more problems and it saves you from resorting to your sander. A random-orbit sander will allow you to clean up some of these problems, but not, in my opinion, leave as desirable a finish as does a plane. Sharpening and Setup You might think that sharpening would be a problem, but it is no different than any other blade. I use a 30° secondary bevel, which gives the teeth a bit more durability and helps hasten the sharpening process. I recommend using a honing guide for these toothed blades because the tiny chisel teeth can easily gouge a stone if it is sharpened freehand. When setting the blade up for use in a plane, set it for a heavy cut, but not as heavy as you will ultimately want. You want to create the tooth pattern in the stock before you try to go to your final depth of cut. That final depth will be as deep as you can manage without losing the effect of the toothed blade. Beware: If you have more than half the depth of the teeth exposed out of the mouth of the plane, then you will begin to use the non-slotted portion of the blade. This will result in you taking a full-width, very heavy, shaving and cause the tear-out you were trying to avoid. I prefer to do my rough flattening at a 45° angle, so that every pass is flattening the board in both length and width. I work evenly from both 45° directions to create a cross-hatched surface. The toothed blade Then a light touch. Before switching to a standard blade, put a light cross-hatch back on the board to make the next step easier. leaves behind a series of grooves that you can "read" to tell what is happening on the piece of stock. When you get a continuous cut in every direction, you know that the board is reasonably flat and it is ready to clean up. I then plane the length of the board to ensure that it is flat in both length and width. My last passes with the toothed blade will leave long continuous grooves in the length of the board. As a final step with the toothed blade I make one more series of passes at a 45° angle across those grooves with just the weight of the plane making the cut. This will reintroduce a cross hatch, but it also gets rid of half of the material that needs to be eliminated to achieve a smooth surface. To get a board from its rough toothed state to a smooth finish you will probably want to use a plane with a high cutting angle. The material is more than likely prone to tear-out or you would not have needed the toothed blade to begin with. To achieve a high-angle cut with the same low-angle jack that you were using for the rough work, simply sharpen a secondary bevel on its normal blade that will give an Final cleanup. With the board flat and free from tear-out, you can then switch to a standard blade to produce your finished surface. appropriate working angle. The blade is bedded in the tool at 12°, so subtract 12 from whatever your desired angle is to determine the secondary bevel angle. I will work as steep as 62° if the material is particularly hard or nasty. (A 50° secondary bevel would give you a 62° working angle.) Typically, a 50° working angle is enough, though. To achieve a 50° working angle, use a 38° secondary bevel. If you have never tried a toothed blade, you will find that it is a very valuable and versatile addition to your quiver of tools. It gives you the ability to quickly and safely work down some stock that you may not have been able to or dared to work before. PW Deneb Puchalski is senior sales representative and show coordinator with Lie-Nielsen Toolworks in Warren, Maine. Sources Lie-Nielsen Toolworks lie-nielsen.com or 800-327-2520 ■ sells toothing blades for both bevel-down and bevel-up bench planes, block planes and scraper planes Lee Valley Tools leevalley.com or 800-871-8158 ■ Sells toothing blades for bevel-up, block and scraping planes Tools for Working Wood toolsforworkingwood.com or 800-426-4613 ■ Sells Ray Iles toothing blades for block planes popularwoodworking.com ■ 49 |
