Sunday, October 19, 2008
Like a charm.
Yes, you're seeing double - blades, that is.
The first year that I taught cedar-strip canoe building, we had some plain steel blades that we were using in a patternmaker's table saw. The progress was painfully slow. As the saw blade would warm up a bit, it would cup and then bind the board being cut. On top of the fact that it was a poor set-up, it was frustrating for the students and it wasted stock because it required the boards to be jointed to get a straight edge on the stock. At the time, it took about 3 hours to rip enough stock for a canoe.
The next year we improved the situation with a Freud thin kerf blade. It was much better as the damping and expansion slots prevented cupping of the blade. The carbide tips and undercut teeth help things go well in the saws at the school. We were cutting one strip at a time and the blade, at .093" thick wasn't bad, but it was slow. We resorted to the same method last year, but used a .062" thick blade intended for use in a circular saw. We wasted less stock to sawdust, and it wasn't bad, but still was slow.
This year, I got serious. I had a brass spacer made to go between two of the .062" thick Freud thin kerf 7-1/4" blades. We set them up in the saw with a stabilizer disk. As you can see in the picture above, we've got a new zero-clearance insert to deal with the gang-sawing assembly. The featherboards and sacrificial fence aren't new, and work well. This year it took 30 minutes to cut a boat's worth of stock. Much better.
Our next improvement is going to be either a power feeder or some of the one-way feed rollers to help crowd the stock into the fence and down to the table.
A final picture of a happy student ripping stock!