Kerf Plane vs Plough Plane

[Eric Schubert]

While doing research on ripping boards by hand, I noticed some advised using a kerf plane to keep the cuts on track. I don't know much about these planes, aside from they lay a groove along the cut line to give the blade a small shoulder to guide it. Is there any reason I would need one of these? Can I just use my plough plane and a narrow iron to do the same thing?

[David Bassett]

*IF* you have and can fit an iron as narrow as your saw's kerf, I don't see why the two options aren't equivalent. (I don't think most irons are that narrow. E.g. the smallest iron LV lists is 1/8" wide.)

[Nicholas Lawrence]

I don’t have one, but I understand the kerf plane is the same width as the saw blade. I do not have any plow plane blades that narrow.

[Tony Wilkins]

Aren’t these kerf planes more like a saw than a plane when it comes down to it?

[Eric Schubert]

That's a good point, the smallest plough plane blade I have is 1/8". I'm guessing if it's too wide to guide the blade properly, the saw will wander around anyway? I just tried this, and sure enough, it seemed to wander a bit on me. I also needed to stone my saw on one side, as it wasn't tracking straight to begin with.

From what I've seen, kerf planes usually use some type of saw blade clamped into the body of the plane. Some are adjustable for distance of the kerf from the edge of the board, some are not.

[steven c newman]

Tom Fidgen has a youtube video out about making such a plane....might be worth watching?

[Phil Mueller]

Second on the Tom Fidgen video. The blade is a saw, not a plane iron. The kerf it makes is obviously the width of a saw plate...somewhere near .035” or about 1/32”. LV does offer a 1/16” router plane blade. Even though that is still twice the thickness of a saw, I may have to give it a try next time I need to resaw something.

[Vincent Tai]

Second on the Tom Fidgen video. The blade is a saw, not a plane iron. The kerf it makes is obviously the width of a saw plate...somewhere near .035” or about 1/32”. LV does offer a 1/16” router plane blade. Even though that is still twice the thickness of a saw, I may have to give it a try next time I need to resaw something.

Fidgen wrote in his book about how he ground down a 1/8th blade to 1/16th for this purpose. Still didn't work. Which is why he pursued the idea of a kerfing plane.

[Phil Mueller]

Thank you Vincent. I think you just saved me a good deal of experimental effort 👍

[Vincent Tai]

Thank you Vincent. I think you just saved me a good deal of experimental effort 

Sorry Phil, I opened the book just now and turns out my memory is a little fuzzy. He writes that he tried with a 1/8th iron in his small plow plane which didn't work. He "thought" about grinding it down to about a saws width but that would've been too fragile and hard to sharpen. I would agree with him. Certainly too fragile unless you drew the temper of the blade back to about a saw's even then its a pretty flimsy small section which I could see going ping and lots of time at the bench grinder wasted in a second.

But perhaps you could still experiment. I have to say I don't see 1/16th working to well, any room in something like this that allows a bit of drift to start might make more work than anything. I don't own any powered saws and for years have been meaning to make a Kerfing Plane and a frame saw but never got around to it. One day....

[steven c newman]

The hitch would be the thickness of the skate....most combo planes have a little bit thicker skates...

[Phil Mueller]

Thanks Vincent. Steven, the router blade could be used with the router plane and edge guide, so there would be no skate to worry about.

In the past, I’ve resawn wider boards using my table saw to get as deep around as it will go, however, the 1/8 kerf leaves a lot of slop for the bow saw. While I did get the two half’s apart, a good amount of planing was needed to clean up the cut.

[Eric Schubert]

Excellent points. It makes sense that you can't really allow the saw any leeway, or it will begin to wander around. I have an extra hand saw or two sitting around here. Might be worth taking the end of the saw off and turning it into a kerfing plane to test it out. I could just turn the rest into a shorter saw.

Steven, I hadn't even thought about that. A plough plane uses that skate. No way would it fit into a narrower groove, unless you grind it thinner. That won't be happening with my Record 043.

[steven c newman]

One other thing...you will need to allow the sawdust/shavings a way to exit the kerf you are making....you start at the far end, and work your way back. Gives a way for any shavings to exit. Just like on most molding planes. Once those teeth get below the gullets, where does the ''cuttings" go?

[Mark AJ Allen]

The idea is that the kerf guides the saw. If the kerf is wider than the saw, it does what it's supposed to do, but very poorly; almost to the point of not bothering making the kerf. I found that ideally, the kerf from the whatever you use (you can build a kerfing plane, but I don't think it's ideal) is slightly smaller than the saw cut.

Kerfing plane sounds like a good idea until you realize the gullets fill far to quickly on a traditional tooth spacing. If you make one like that, you have to use it like a plow plane; don't make long passes and make sure you clear your gullets when you have to.