I'm surprised at how often this
situation arises. After all, I don't build solid top workbenches or oversized
cutting boards all that often. But, several times, I have been faced with the
problem of how to cut a large glued-up slab.
Depending on the situation, I'll use either a circular saw or a router to make
the cut. To be honest, my circular saw and I have never gotten along all that
well when doing finish work. The saw does a good job when rough cutting plywood
and chopping 2x4's. But any time I try to make a straight cut in something
thick, like Maple, I'm not happy with the result.
Even with a carbide-tipped saw blade, the cut can make rough heavy saw marks
and burns. And often the exposed shoulder isn't a nice clean, straight line. So
here are some ideas for avoiding the problems I've encountered.
If you glued up a slab a foot or so longer than necessary, you will have some
extra material to *try* using a portable circular saw to see if you can get a
straight, smooth cut. (A little experience can be very helpful.)
But whether this is a test cut or the final cut, first position the slab so the
good surface of the slab (the top) faces down. This minimizes chipout on the
good side since a circular saw cuts up from the bottom. Now clamp a fence on
the slab (at 90 degrees to the edges) for the shoe of the saw to run along. Set
up the cut so the heaviest part of the saw (the motor) is over the workpiece
rather than the waste. This will help keep the saw stable. And to prevent
chipout at the end of the cut, clamp a piece of scrap wood to the far edge of
the slab.
When making the cut, think about pushing the saw all the way through. Don't
slow down or the cut will burn and create heavy swirl marks. The idea is to
keep feeding the saw as fast as it will cut without bogging down.
Next week, we'll use a hand-held router to clean up the edge left by the
circular saw ;-) and, as an alternative, talk about how to use the router to
make the cut itself and avoid the circular saw altogether.
Go to Tip #66 |
