Because my table saw has one of those thin metal blade inserts, I’ve been thinking for quite a while how to make a zero clearance insert for my saw. I cut quite a few small or thin items and often, as might be expected, the thin cuttings fall down the slot between the insert and the blade. Only once did this actually result in something a bit startling, but I wanted to remedy the situation in any case.
At one time, I tried making a ZCI by dadoeing around a hunk of wood so that it would fit in the space. I had to hollow out in the location of the blade because on these saws the blade just barely goes below the surface of the table at its lowest position. I had to rig up a finger clamp to hold it in place, just for peace of mind, if not actually for safety’s sake. Eventually that experiment broke in half, so I put my old metal insert in and continued thinking about it…
...for two years.
Last week I got an idea that might solve my problem easily and cheaply. I wasn’t able to actually do it until today.
Above: I cut a piece of hardboard, the kind that is 1/8 inch thick to cover the throat of my blade insert (about 2 inches). I glued it on to the underside of the insert with hot melt glue. That way, If I need to make an angled cut, I can just snap it off ‘easily’.
Above: Then I took another strip of the hardboard that I had previously cut to fit in the throat of the insert and I glued it onto the hardboard that I glued to the underside. When it was dry, I lowered my riving knife and set the insert correct side up in its place. Because of the blade situation (read above) I had to turn on the saw and then push the blade insert down from the edge nearest to me. This is probably the only remotely dangerous part. Then I turned off the saw and brought my fence over to hold the metal insert in place. Then I turned the saw back on and raised the blade up to full height.
It didn’t come flying out and hit me in the eye or anything, so I think it will be OK. If you look at the photos you’ll notice that the area where the riving knife goes does not have zero clearance. This is because that area of my blade insert is on a different level and it would be difficult to put a ZCI section there. Also, I’d have to manually cut the slot for the riving knife and that would be a pain.
I used the saw this way all day today and it’s still working well. It’s not quite as convenient as a full ZCI, but it’s better than nothing at all and not so inconvenient as I rarely make miter cuts by tilting the blade.
-- Ni faru ion el ligno!