Expert: Jamie Yocono - 12/13/2007

Question
I am going to build a small bench, (36Lx14Wx 20H) from some pine shelving that I have that is 3/4x11.  I want to rip these boards so I can glue up the top from several pieces.  The boards have a slight cup in them.  
When riping, should the cup be down, (concave down) or cup up?
Thanks,

Answer
Hi Peter,

I like to rip boards (with a slight cup) with the rounded side down on the table, the higher edges running against your long fence. That way, when you complete the rip, the board splits apart nicely. If you do it with the cup (rounded) part on top, as the cut completes, the two boards want to drift down toward the sawblade as they separate. You DEFINITELY don't want that, as they can kick back.

I've seen some articles that suggest you tape a wood shim under the high spot on the cupped board, that way, you give the board more support, and less room for movement while you're cutting it. I agree in principle, but have never done it. I just hold the board steady when ripping it. Don't let it flop down when the two pieces separate, and you should be fine.

Hope this helps.

Jamie Yocono
Wood It Is! Custom Cabinetry
Las Vegas, NV
www.wooditis.com