Disassemble the buck saw. Grasp the windlass handle and unwind the tensioning cord counterclockwise. Remove the pins from each end of the saw blade. Lift the saw blade free of the saw frame.
Place the buck saw blade in the saw vise with the teeth up and pointing to the right. Position the blade so that the right-hand portion of the blade sits securely between the vise jaws, with a fingertip's width of blade above the jaws of the vise.
Check the set, which is the angle at which alternating teeth bend to opposite sides of the blade. Sight along the side of the blade to spot any teeth that bend too far out of line. Use the saw set to adjust an individual tooth or the entire saw blade, one tooth at a time. Saw sets work like pliers, with one jaw acting as an anvil and the other as a press.
Joint the saw with the mill bastard file. Place the flat of the file on the saw teeth, which provide a narrow base for the file face. Cup fingers around the file, guiding the file by running fingertips below it as the file slides forward. Reposition the blade in the vise as needed and joint the full length of the blade.
Check the teeth of the saw to be sure all are jointed to the same level in a perfectly flat plane. Each tooth should show a small flat space of filed metal on the tip.
Sharpen the fleam--the bevel of the saw tooth's forward edge--with the triangular saw file. Fleam angle usually falls between 20 and 25 degrees. With teeth pointing from left to right in the vise, find the fleam on the right side of the teeth. Work on the teeth set to the near side of the blade first.
Rock the flat of the saw file against the fleam of the first tooth to feel the correct angle. Make a full forward stroke of the file and continue until the flat space left by the jointer file vanishes. Remove steel from the entire height of the tooth to preserve the rake, or forward angle.
Finish all the teeth on the near side of the blade before reversing the saw blade in the vise. Since teeth now point the opposite direction, the fleam angle reverses but the technique remains the same. Sharpen the fleam on the teeth of the remaining side.