SHARPEN TO PRUNE

By ROBERT A. FANNO

The Fanno Saw Works

Chico, California

A DULL pruning saw is about as ing saws in top shape. the saw sharpener a new starting ** useful to a tree climber as a 100 Yet when it comes to keeping this point to continue with the rest of pound backpack. There's a drag on important tool sharp, few arborists the sharpening steps. It is best ac- both that can't be tolerated very know the steps involved in success- complished by using a large flat file. long. ful saw sharpening. Basically, there One or two strokes of the file across Pruning saws are at the heart of are five critical steps to sharpening: the tips of the teeth will usually be the business for the professional joint, shape, set, bevel, file. sufficient. The trick is not to file off arborist. A recent survey of pro- The pictures tell the story. Note any more of the teeth than neces- fessionals in this field showed more that you can usually tell whether sary to bring all of them to a than 25 percent of every job bid in- a saw needs sharpening by the bevel standard height. volved pruning and trimming. With and the unevenness of the teeth. Shaping comes next. Nine out of this kind of interest, tree care men By jointing, the teeth are brought ten times this step can be avoided. have a high stake in keeping prun- to a standard height. This step gives It's only needed on saws that have

This is a typical saw that needs to be The blade above has now been jointed. Use a large flat file to joint curved sharpened. Notice how the teeth are Jointing is the process where the teeth pruning saws. Usually one or two uneven in height and bevelled wrong- of the saw are brought to the same strokes across the tips of the teeth run- ly. It does not cut cleanly or smoothly. height. This gives you a starting point. ning the blade length will do it.

For straight saw blades, use a jointing This is called shaping. You can avoid What you see is the set of the saw. It tool. Note how saw blade is securely this step most of the time. It's only refers to the alternating tooth pattern held in the vice so it won't wiggle or needed if saw is badly sharpened or while looking down from above. It's come loose. neglected. important that saw set is correct. been badly sharpened or neglected. over and set the other side. A good Shaping brings the teeth back to vice is a must. their original size and shape. Gen- If you are looking for shortcuts, erally, a grinding wheel applied consider a combination of the last lightly to the teeth will quickly ac- two steps. In the process of filing, complish the job. you also put a nice bevelled edge on Probably the most important step the tooth. Our saws at Fanno Saw in sharpening a pruning saw is set- Works have the edge of the teeth ting. The set of a saw refers to the bevelled about 15 degrees. Other alternating tooth pattern. You can saw manufacturers vary. We also see this by looking down on the tops have a four degree negative hook of the teeth. The average of amount on our saw teeth. This refers to the of set is .025 to .030 inches for each direction of the teeth and also where tooth. This means that each tooth the cutting edge is placed in rela- should be set left or right of tooth tionship to a given centerpoint. We've found this to be of real ad- center by just a fraction of an inch. Here's the tools you need to sharpen When cutting green or fibrous vantage in terms of life of a given your own saws: a six-inch Cant saw wood, you'll need more set. Some saw. file, large flat file for jointing, pistol- grip saw set tool, and jointing tool for arborists refer to this as bite. Hard- That's about all there is to sharp- straight blades. woods and deadwoods need a lighter ening pruning saws. Note the differ- set in the saw. The set of the saw ence between the dull, disjointed determines the amount of cutting blade in the beginning and the same ing stone down the saw blade after you've filed it that the edge will be edge exposed to the cutting surface. blade when sharpened. Quite a dif- You can put set in a saw by hand or even sharper when you use it. The ference! The sharp saw has uni- by machine. Stanley Tools makes a honing stone takes off the metal formity between teeth and exhibits pistol-grip saw setting tool that is burrs. easy to use and accurate enough for a keen edge that will cut quickly Saw sharpening is not difficult. the professional arborist. If you and true. If you're still in doubt about sharp- hand set your saws you set the teeth One special tip on saw sharpening. ening your saws, consult a pro- on one side and then turn the blade We've found that if you run a hon- fessional. •

Not all saws have the same set. The You can buy a pistol-grip saw setting When you file a saw, you also put a average amount is .025 to .030 inches tool for your saws. Stanley Tools makes nice bevelled edge on the tooth. Fanno for each tooth. You need more for fi- an acceptable unit. Set the teeth on saws are bevelled about 15 degrees; brous wood; less for deadwood. one side first and turn saw over. other saws vary.

This man has been making and filing Here's a freshly sharpened saw. Com- A final saw tip. Lay saw on flat sur- saws for 35 years. Note how he holds pare it to the first two pictures. Note face. Run a honing stone down the saw file. Saw vice holds saw firmly leaving the joint, shape, bevel and file. Saw blade to take off metal burrs. It will blade exposed. will cut fast in this condition. put a professional touch to your work.