General Meeting October 8, 2014
Set Your Teeth on Handsaws by Larry Simmons
Larry opened with some common definitions useful for the balance of his presentation.
PITCH: Teeth per inch.
RAKE Angle: Larry presented a chart showing the different rake angles based on whether a saw is a rip or cross cut saw, and also dependent on the saw’s use in either hard or soft wood. Zero degree rake angle means the front of the saw’s teeth are presented at 90 degrees to the surface of the wood, for instance.
FLEAM: The angle of the file when sharpening the teeth. Fleem refers to filing the back of one tooth and front of the other. Usually zero degrees for a rip filed blade, and ranging from 15 to 25 degrees on crosscut saws.
HANG: The angular relationship of the saw’s handle to the cutting edge. The handle needs some downward angle in order to transfer some power to the cutting edge. Aside from hang, many people purchase a saw based on how well it fits the individual’s hand. (If it feels good, it probably is, for you.)
RUN: This is the hand saw equivalent of runout on a machine tool. To demonstrate, draw a line to be cut and begin a cut by hand. After well underway, look away and continue sawing. If the saw does not follow the line, that is the run.
PPI: Points per inch.
Larry’s interest started from the acquisition of a hand powered cast iron miter saw that is almost as heavy as a powered miter saw. The blade was caked with dirt and dull, so Larry decided to learn how to sharpen hand saws. Larry often omits a power saw on his jobs, instead just powering the saw by hand.
Larry showed some various saw types. Ripping saws have teeth with a flat bottom (looking from left to right on the saw)and some set. Crosscut saws have teeth filed on an angle, and also have a set.
Disston hand saws have a distinctive emblem on one of the sex bolts or saw bolts. This brand is highly regarded and formerly they had 75% of the American market. More of the history of Disston hand saws is available on the internet.www.disstonianinstitute.com
Saws are measured by the blade length, and saws were sold by the inch. Commonly, rip saws were a little longer due to the angle the worker used, a lesser angle allowed a longer blade to be used without hitting the floor when using a saw bench.
Larry’s rip saw has 6 teeth per inch. Rip saws are ineffective when used in a crosscut manner.
Panel saws are so called because they are shorter than others and often were fitted into the lid (or panel) of a workers tool box. Aside from that, they mimic other saws.
Triangular files are used to sharpen saws. Larry presented a chart showing the size files used depending on the pitch of the saw. Try to avoid using more than ½ of the file buried in the teeth so that when one edge of the file wears out, it can be rotated 60 degrees and further used.
Jointing saws does not refer to the current medical marijuana initiative, but rather to setting all the file teeth in the same plane. Larry showed a flat mill bastard file set into a short board, which not only holds the file, but also holds the file at 90 degrees to the blade. A few strokes will usually make all the teeth the same height.
To joint the saw, Larry fastened the saw in a saw vice he purchased.
He also showed us a board with a kerf cut in it that can be made as long as needed. Just take a board of sufficient length and cut a saw kerf in it. Now, slide the saw in the kerf lengthways, and that board will hold the saw when clamped in a vise. The shiny spots at the top of the blade prove the height of the teeth. Teeth with larger flat spots means that the files needs to be pushed more into the tooth with the smaller flat spots. To add fleam, Larry uses blocks of wood with saw kerfs cut at the desired angles to help guide the file during sharpening. He no longer believes that most saws need fleam, stating that Paul Sellars taught him that, and he tried it and feels it works just fine.
Larry feels most saws have too much set, and cut too wide of a kerf. These saws are even difficult to withdraw from a cut on the back stroke. The saw set tool has two pistons, one to grip the saw and one to bend the tooth. There is a number adjustment on the saw set, with 4 corresponding to four teeth per inch. Make this adjustment when starting and the set is introduced when the handle is activated.
After setting the teeth, joint the teeth again, but very lightly. Now sharpen again, perhaps only one stroke will remove the flat spot.
Dovetail saws are usually filled with a rip cut. Larry said Youtube has hours of videos showing how to sharpen hand saws. Search for Brit01425 on Youtube.
Show & tell
Fred Damianos made a walnut desk name plate
Denny Wetter made an open segment bowl and a turned box
Larry Simmons brought in an old plane
Joe Mathis brought in an intarsia eagle and a fretwork fairy
Ed Fraser brought in some micrometers and locks
Alan Penn brought in some miniature Kachina dolls and an amazing carved dog
John Slezak brought jigs for helping set cross pieces repetitively