We are trying to end match pine flooring on a double end tenoner. The boards are previously tongue and grooved on the edges by a molder. Up to several inches of the edge tongues are torn off when the boards come out of the tenoner. We have slowed the tenoner feed speed down to the minimum and gotten no improvement. Would appreciate any suggestions.
From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
This is a common problem. One solution is to machine halfway in one direction and then reverse the piece and go the other direction. This means you will not be machining the edge and give it a chance to split out instead of being cut off. Of course, you will have to use a router, spindle shaper, or other similar machine, and not a DET.
As you get close to the end of the cut, the wood asks itself if it is easier to be cut off or if it is easier to split off. The question you might ask is why there is so much force trying to cut the wood, so that splitting is easier? Is the tool sharp (HSS rather than carbide), with a small amount of stock removal, including shallow cut (several passes)? Also ask if the wood over-dried (under 6% MC) so that it has become brittle and is easier to split than to cut.
As a last resort, some people will glue a temporary block on the exit edge to help hold the wood together and avoid exiting in the work piece. Any exit splits would be in this temporary piece.