How does a plow plane produce a clean cut without a nicker?

[Greg Portland]

I've been looking at plow planes and am wondering how they get a clean cut without any nicker blades? Won't these cause tearing along the edge of the cut? Especially the plow plane models that offer wider blades (3/4") ? Is starting each edge with a knife recommended?

[Frederick Skelly]

Isnt it because a Plow cuts WITH the grain. So you dont need the nicker.
A Dado cuts across it and needs a nicker for sure. (Been fightin that one all week!.)

[Maurice Ungaro]

Isnt it because a Plow cuts WITH the grain. So you dont need the nicker.
A Dado cuts across it and needs a nicker for sure. (Been fightin that one all week!.)

What Frederick stated. A Plow cuts WITH the grain. No nicker need apply for the job.

[Jim Matthews]

I've begun to experiment with the method shown by Derek Cohen using a large saw to score
the sides of a cross grain groove (dado or rabbet). It works. It's not difficult, and it uses tools we already have.

If you cut more with the grain, a plow plane is excellent. If you're only cutting the occasional dado,
it can be managed with a router plane and a sharp saw.

[Jim Koepke]

If the wood is nice and straight grained, a plow plan will cut a smooth groove.

When you get switching grain you will get fuzzy sides or other chip out along the edges. Most of the time this will not be noticed. Eventually you will learn to use the best grain orientation for your plow work and keep tear out to a minimum. A side rabbet plane helps to clear up the sides with one or two passes.

As to the physics of the process, the edge of the blade has a very high angle grind. This acts a bit like a scraper on the side of the cut and helps to burnish the surface.

jtk

[Judson Green]

I've begun to experiment with the method shown by Derek Cohen using a large saw to score
the sides of a cross grain groove (dado or rabbet). It works. It's not difficult, and it uses tools we already have.

If you cut more with the grain, a plow plane is excellent. If you're only cutting the occasional dado,
it can be managed with a router plane and a sharp saw.

That's been my way of doing it maybe not with a large saw though. Also like using a shop made depth stop clamped to the saw.

IMAG2266.jpg

[Frederick Skelly]

When you get switching grain you will get fuzzy sides or other chip out along the edges. Most of the time this will not be noticed. A side rabbet plane helps to clear up the sides with one or two passes.

As to the physics of the process, the edge of the blade has a very high angle grind. This acts a bit like a scraper on the side of the cut and helps to burnish the surface.

Thanks Jim. I always wondered why someone would need a side rabbett plane. Now that youve explined it, I want one too. Also didnt know the actual physics of the plow plane cutter design. One thing I find fascinating about old planes is that through daily use and trial and error (over centuries), pretty sophisticated designs evolved. Intellectually, it makes perfectly good sense. But its still pretty darn amazing to me on an emotional level.

[Zach Dillinger]

It is good practice to lay out your grooves with a marking gauge before using your plow. The purpose is to ensure you plow a straight groove, as fences on plows do slip and the lines let you see if / when that happens. Severing the grain in less-friendly wood is a happy by-product of this effort. Plowing with the grain usually works just fine without tearing things up anyway.

As for cleaning up the sides of the groove, I prefer a t-rabbet plane if the groove is wide enough.

[Brian Holcombe]

Frederick,

I have a side rabbet from Terry Gordon and it's very well done. I use it in conjunction with a dovetail fence most of the time, but also without to clean up rabbets.

Terry's stuff is really well worked out, I have designs on purchasing a dado plane or two from him fairly soon.

[Jim Koepke]

As for cleaning up the sides of the groove, I prefer a t-rabbet plane if the groove is wide enough.

I am not sure what a t-rabbet plane is. Could you post an image or a link?

jtk

[Frederick Skelly]

Frederick,

I have a side rabbet from Terry Gordon and it's very well done. I use it in conjunction with a dovetail fence most of the time, but also without to clean up rabbets.

Terry's stuff is really well worked out, I have designs on purchasing a dado plane or two from him fairly soon.

Yeah, his tools are SOOOO nice. I hadnt noticed the side rebate planes last time I was "there". Thanks Brian!
Fred

[Jim Matthews]

That's clever.

You can set the stop lower to act as a prop
and raise it as you go along.

I chisel the sides a bit on dadoes
and ran a small sash saw along the ridge.

[Winton Applegate]

Frederick,

why someone would need a side rabbett plane

Good for correcting the fit of a box lid too (actually the rabbet that goes into the lid) that has swollen too tight to close easily.
And they are cool as heck to look at.

[Winton Applegate]

It is good practice to lay out your grooves with a marking gauge before using your plow.

Or even get crazier than that and use a cutting gauge.

[Frederick Skelly]

Frederick,


Good for correcting the fit of a box lid too (actually the rabbet that goes into the lid) that has swollen too tight to close easily.
And they are cool as heck to look at.

Oh man. Those ARE cool to look at Win. like most LN planes, theyre downright beautiful to my eye.