Power planer v. plane

[John Schreiber]

Why is it that I can sometimes plane wood without tearout with a lunch box style power planer, but when using a hand plane I get tearout?

Just something I've been thinking about as I plane away.

[Douglas Brummett]

Maybe technique, maybe a tricky board. I dunno. I am just crossing over to the neanderthal side on planes myself. But I do notice that if my mind wanders I can dig the iron in, go cross grain, and generally make a mess. I was playing around with a piece of walnut scrap the other day and it had a most ridiculous grain, there was no right way to plane it (had to switch direction 3x over the 18" length to keep up with it).

It also might have something to do with the power planer chipping off the shaving with the high speed cutter traveling at relatively slow feed rate. The hand plane has a similar feed rate, but a continuous cutter that will follow the grain to an extent and lift it.

[Johnny Kleso]

Wood has a grain to it and when planing by hand or Power you always when the grain (viewed from side) running down toward the cutter..

This for Hand Plane push plane like this ---/-->

This for Power Plane feed board in like this ---\-->

Why it tears out one more then another depends on many other things like how sharp the cutters are what angle they attack at, does the grain reverse at a knot..

[Jim Koepke]

Wood has a grain to it and when planing by hand or Power you always when the grain (viewed from side) running down toward the cutter..

This for Hand Plane push plane like this ---/-->

This for Power Plane feed board in like this ---\-->

Why it tears out one more then another depends on many other things like how sharp the cutters are what angle they attack at, does the grain reverse at a knot..

An extremely sharp blade and tight mouth will also help. If the grain is irregular, then one needs to either plane in small areas in different directions or try a scraper.

jim

[Wilbur Pan]

It also might have something to do with the power planer chipping off the shaving with the high speed cutter traveling at relatively slow feed rate. The hand plane has a similar feed rate, but a continuous cutter that will follow the grain to an extent and lift it.

This is exactly it. Even though both the machine and the hand tool have the word "plane" incorporated into their names, the mechanism by which a power planer removes wood is much different than what a hand plane is doing. The power planer takes out a very short shallow scooped chip with a blade at high speed. A well tuned hand plane is taking a continuous shaving.

[John Schreiber]

. . . the mechanism by which a power planer removes wood is much different than what a hand plane is doing. The power planer takes out a very short shallow scooped chip with a blade at high speed. . . .
That makes sense. A short shallow scoop is not the same as a wedge trying to separate the grane.

[Douglas Brummett]

2nd the scraper. I have a piece of maple with a swirl in the grain and no matter what a plane just chunks it. The card scraper was far more predictable and functional with the difficult grain.

[John Schreiber]

I ask because I've been working with a ton (exaggeration, really only about 300 lbs) of southern yellow pine. I've been able to run it through a power planer from either direction without any tear out, but when using a #7 jointer, I've got to test to see which direction works and on some pieces, I've got to go from multiple directions.

[Cliff Rohrabacher]

Lay the plane off at an angle to shear and you might consider setting a blade or two aside that you will have cambered a tad. Pull 'em out when planing down a wide flat surface.

[Don C Peterson]

I've wondered the same thing, there is no way that the power planer is sharper than my hand planes etc... I've convinced myself that one of the key differences is the cutting angle.

If you look at power tools (router bits, planers, jointers, table saw blades, etc...), they all have VERY high effective cutting angles. My power planer (a Dewalt 735) has an effetive cutting angle that ranges from about 85 to 70 degrees. That puts it at the same cutting angle of my hand scraper... There's just no way that a hand tool can work effectively at those angles, at least not when removing any amount of stock.