Posts Tagged ‘marking knife’
If you have been following along in parts one through four, you should have your tail board finished and your pin board dimensioned. The next step is to transfer the tail locations to the pin board by using the tail board as a template. This is why you don’t need to precisely follow the angle you laid out when sawing your tails, any slight deviation from the pencil line will be transferred to the pin board and copied exactly. Missing your slope is purely cosmetic and the joint can still go together seamlessly. To transfer the tails, align the pin board so it’s even with the side of a bench plane or block of wood as pictured below, then clamp it in the vise. Slide the plane/wood back and use the tail board to bridge the gap. Now the shallow rabbet that was created in part 1 becomes extremely useful. Slide the tail board up to the pin board until the small shoulder from the rabbet hits the pin board. You should immediately feel the rabbet’s shoulder align the board. This accurately solves two of the three alignment problems you can encounter in this step: 1) skewing or rotating the tail board relative to the pin board and 2) sliding the tail board too far forward or not far enough. All you need to do now is slide the tail board side to side until the edges are aligned. A block of wood can help.
Now use your off hand to press in the middle of the tail board, locking it in place. Use your dominant hand to hold a marking knife and scribe the tail locations into the pin board. I’m using the thin kerf knife from Blue Spruce Toolworks as it can fit between any tails I cut. For larger work I typically use a larger knife. Press the knife firmly against the tail with the flat face touching the tail. If the beveled face of the knife is against the tail the knife line will be offset and your pins will be far too thick. Draw the knife along the tail with light pressure, but repeat this a few times until a clear line is visible. Again, be sure to keep firm pressure on the side of the tail so the knife doesn’t stray.
Once the tails are transferred, mark the waste (the tails obviously, we want to keep the wood that will go between the tails which are called the pins) and using a marking gauge, scribe the baseline as was done in Part 1, but this time only mark the faces. The edges will not be cut off so there is no need to carry the baseline all the way around the board. Be sure to reset the gauge to the thickness of the tail board as it is typically not the same as the thickness of the pin board. Having a dedicated gauge for each measurement is helpful when several joints need to be cut.
Now clamp the board in the vise for sawing, being sure to align it vertically first. If it’s clamped at a slight angle you will have a hard time hitting your vertical lines right off the saw.
Now use a square or dovetail guide to mark vertical lines, these will help guide your saw. I like to draw them in the “good wood” portion of the board so they aren’t sawn off. Then when the joint is cut I can see how parallel my cut was to the vertical line. This will give me an indication of any clean up work I’ll need to do with a chisel.
Now to saw the pins. The same sawing techniques apply that were discussed in part 3, but you aren’t sawing square across the board this time, you are trying to split the knife line. This means with saw cutting on the waste side of the line, the edge of the kerf should land right on the center of the knife line. The cut must then go straight down, parallel to the vertical lines that were just drawn.
With the sides cut, saw out the waste with a fret or coping saw, then chisel the baseline exactly as was discussed in part 4. Be sure to check that the baseline is square and without humps that could prevent the tail board from seating fully when assembled.
For the next (and likely final) part of this series we’ll be fitting the pins to the tails, gluing the joint, and cleaning it up. Until then, happy joinerying.