Dealing with Planer Tear-Out

Craftsmen discuss tooling and operator techniques for minimizing tear-out from planing lumber. November 12, 2005

Question
At the Las Vegas show I saw the Shelix planer head. I have a 15" Delta planer, and I just had the knives sharpened but it still wants to tear-out on maple. Any help or suggestions would be appreciated.

Forum Responses
(Cabinetmaking Forum)
From contributor A:
From what I read on these forums, multiple overlapping knife type cutter heads leave ridges, but the helical/shear type cut will lessen tear out. A lot of woods, including maple, will tear out in the planer if you feed to the knives against the grain in the board. I have a straight knife planer and I deal with the issue of tear out by first flattening one face of the stock on the jointer.

I look at the edge of each board and make an estimate as to grain direction. If I hear the grain tearing, I reverse the board for the next pass. After I know which way each board machines the best, I have simple methods to keep track of it. Then when I plane them to thickness, I run the boards according to what I learned about their grain direction on the jointer.

In the event that a board is straight and flat enough to go directly to the planer without the need to face joint, I estimate the grain direction and take a light pass through the planer. If the grain tears out, I reverse the direction of feed for that face. This method is difficult if you use S2S (13/16") material and need to net 3/4" thickness. I almost always inventory 15/16" hit or miss as my 1" material. 15/16" material leaves lots of room to plane out any tear out if a board gets planed against the grain at first.


From contributor B:
The next time you talk to your sharpening guy, ask him about back bevel.

From contributor C:

I run all my maple on a widebelt sander 36 grit then up. It takes time but I have no tear out at all. I make doors mostly. Another thing I do is to make one extra panel the largest size as a spare in case something happens in the process (panel raising), then use it for drawer fronts. This saves time in the end.

From contributor D:
Since you asked about the Shelix cutterhead, I'll comment on that. I've had one in my 20"SAC planer for a year and a half now and swear by it. It does eliminate tear out, and because they are carbide inserts in the cutterhead, I was able to run at least 80,000 lf through it before I rotated the inserts. It is a very cost effective method. People say you can see faint lines in the board after it's been planed with a Shelix head, and you can, but you can also see knife marks after you plane with a sharp set of HSS knives. Anyway, who doesn't sand their wood after it comes out of the planer?

From the original questioner:
I ordered the Shelix head and it takes about six weeks for shipment.
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