Sharpening Big Crosscut Saws

Raker-toothed crosscut saws operate on the same principle you find in planes that work across the grain. They first slice across the grain with knifelike blades and then shave out the wood in between. Learn to sharpen them and they won't be such "misery whips." When all is right, the saw works easily and pulls out long strings of wood, severed by the slicers and planed free by the rakers.

The crosscut saw can make its own filing vise out in the woods. Saw a kerf in a log just deep enough so that you can set the saw in it with the teeth sticking up. You could also lay the saw on a stump and file the bit that hangs over, or you can wait until you get back and sharpen the saw while holding it in a proper clamp. In any case, the steps are jointing, fitting the rakers, sharpening the cutters, and finally, setting.

Jointing brings all the slicing teeth to the same height. Lightly pull a file down the tops of the teeth, taking care to hold the file exactly square to the sides of the blade. Stop when you have brightened the tips of all the slicing teeth.

The rakers need to sit slightly farther back than the other teeth, about 1/100 inch for hard wood and 3/100 inch for soft. Combination sharpening tools have a bridge that rides on the tips of the teeth and an adjustable window to drop over the rakers. You can set the depth of the window with a feeler gauge (or with the thickness of a matchbook cover) to guide your file precisely, topping the rakers at the proper depth.

The cutters and the rakers are now at their proper and consistent lengths, but flat tipped. Sharpen the rakers by smoothing their vertical face square across and then filing the back slope. The flat should almost disappear, but not quite. Stop when one more stroke of the file would take away that last bit of the flat tip.

Shape the profile of the slicing teeth to a slightly rounded 60-degree point, with the bevels from between 30 degrees for soft wood and 45 degrees for hard. Again, file until the flats from jointing almost disappear.

Set the teeth by either bending the tips away from the bevel side with a slotted saw wrest or hammer-setting them on a stake anvil or against an axe head or sledgehammer held in one hand. All you need is something with enough inertial mass to stand up to the eight-ounce setting-hammer blows delivered with your other hand. Mount the saw upright in a vise and position the anvil 1/4 inch below the tip of a tooth. Strike the base of the tooth bevel, bending it over the anvil. A set of 1/100 inch is good for hard wood and up to 3/100 for soft wood. Measure the set of the teeth with a saw-setting spider, a three- or four-legged rocker gauge. If the spider were a table, one leg would be short by the amount of set you desire. Move on down the saw, setting and checking every other tooth to one side and then completing the other side.

File the rakers using the guide on a combination tool. This one also has a saw wrest, a hammer, and an adjustable three-legged spider (lower right).
A perforated lance-toothed saw casts its shadow on a peg-toothed crosscut.

left: A cant hook helps you roll the logs about...

right: . . . but a timber carrier lets you share the fun.

In simple peg-toothed saws, the teeth are having to do two jobs. They have to slice across the fibers, and they also have to break the tiny chip, force it to the middle, and carry it out of the cut. If we made them sharper, more knifelike, they would slice better—but then they wouldn't break the chips and carry them out as well. We can only make the saw teeth sharper if we add another type of tooth to the team, one that can both break the chip and carry it away. This is the raker tooth. It rides a little bit back from the points of the cutters, allowing them to do their job before routing out the wood left in the middle of the cut.

None of these teeth will get very far if the saw doesn't have enough set—the alternating outward bending of the teeth that allows the saw to make a kerf wider than its thickness. If we take the practical maximum set of a saw tooth as one-third the thickness of the blade, then the kerf could be two-thirds wider than the blade is thick. This keeps the blade from binding, but it also means you're cutting two-thirds more wood. You want enough set to keep the saw cutting freely, but no more than that.

Olive oil on the saw can keep pine sap from gumming up the works, but neither set nor soap can keep a saw moving in a pinched kerf. If you have arranged the landing spot so that the log is supported in the middle, the kerf will open as you saw. But when a log sits so that it is supported more at the ends, you'll get halfway through and gradually find your saw seized by several tons of pressure.

Wedges driven into the kerf above the saw may keep it open, but wedges won't open a pinch in a heavy log. Try to roll the log over and continue the cut from the side. Of course you can't roll a log with a saw pinched in it, so all you can do is try to lever the log up and jam a support beneath it.

If none of this works (and assuming you can get the saw free from the kerf), you can make a second saw kerf parallel to and an inch or so over from the first. When this kerf starts to pinch, pull the saw out and, standing on top of the log, swing down with the poll of your axe and pop out the intervening wood and continue sawing. This is a neat trick, but it hardly redeems the nuisance.

right: . . . but a timber carrier lets you share the fun.

The "drug" — a cylindrical roller mounted in a wooden frame.

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