Okay, everyone, prepare to be re-acquainted with what could be construed as one of an 18th century woodworker’s secret weapons. (Drum rolls, please.)
The toothing plane, a tool that has gotten me out of more difficult situations than I care to admit.
Actually, as more of today’s woodworkers delve into traditional methods, the toothing plane has become less of a secret. But for those who may be new to this tool, I”ll explain its features. More importantly, I’ll show how extensively it was used in 18th century shop practices.
A toothing plane is simply a very high angle block plane equipped with a blade that has a serrated edge. The pitch angle of the blade noticeably varies from tool to tool, anywhere from 65 to 90 degrees. The coarseness of the teeth can vary as well, but we have seen a trend where the higher the pitch angle, the finer the teeth. Here are photos of a few we use in the shop (the one on the far left is my personal one).
So the plane does not shave like an ordinary one, but scratches the surface of the wood. You take off strings rather than full shavings.
The surface is left textured with fine grooves, like this:
A sharp card scraper can smooth out the scratches to a finished surface.
Why go to all this trouble? Easy answer. The toothed edge ignores grain direction and figure in any board. It allows for working a surface in any direction, either with the grain, against it or across it. The teeth won’t dig under contrary grain and tear it out, as would the full blade width cut of an ordinary plane. So while the surface is scratched up, it remains intact. And yes, it is slower than a conventional plane, but keeping a untorn surface makes it worth the effort, and these planes can be set to cut rather aggressively, if necessary.
I hear the next question, from those techno-minded souls: how did they serrate the blade edge and how did they sharpen it? Here is a picture of a couple of blades:
As you can see here, the blade’s face is grooved. Before the blade was heat tempered (and thus still workable), the cutler chiseled the grooves into its face, the indentions forming their profile on the edge, creating the teeth. Old ones show that the chiseling was done by eye, just enough irregularity that identifies it as hand work.
Sharpening? You can treat it as a regular plane blade. Hone the bevel in your usual manner, then gently wipe the burr from the flat side so as not to disturb its grooved profile.
Where could a workman use this plane? Just about everywhere except, logically, carved surfaces. Working woods with curl, crotch or burl figure became safe and feasible, as here:
So when beautiful woods were hand-sawn into veneers, the toothing plane safely worked off the saw marks without risk of gouging. Compare the two veneers below. This is relatively plain walnut, but note the surface textures between them: rough saw on the left, toothed on the right (note the marks running across the grain but still intact).
The toothed surface was left on the veneer and the substrate was toothed as well. Both textured surfaces came together with hide glue as an aid in adhesion. They also minimize slippage if you want the veneer very precisely placed, such as these oval designs executed by Kaare Loftheim (under my guidance):
Here’s a great shot of toothing marks from the 1726 English spinet harpsichord on which I’m basing my current project:
As you see, the tooth marks are strictly made to aid glueing the veneer, and appear nowhere else on the board.
Since 18th century veneers were usually thicker than the modern stuff, the toothing plane could finish the exposed surface followed by scraping and sanding, as I did for these cheeks for the keywell assembly:
We can get beyond veneering. Since these tools allowed full freedom to work from any direction, old furniture pieces often show evidence that toothing planes were used with abandon on unimportant, unseen surfaces. You’ve seen the marks on the antique spinet. Take a look here.
The inside carcass of an antique gentleman’s cabinet, on which we based the replica in our wareroom:
Here is the underside of the original Peter Scott tea table that Brian Weldy is reproducing now. Note the tooth marks on the skirt edge as well as the bottom face of the top.
In these instances, the toothing plane may have been a reliable way to flatten out any track marks or imperfections left from regular planing. On exposed surfaces the scratches would be scraped away for finishing, but on the secondary surfaces, they are left behind.
So toothing planes played a big part in shop methods during our period. Taking a cue from these and other original items, I’ve begun to use them more myself.
So how can today’s woodworkers follow the same option? The only modern equivalent I’m aware of are the toothed blades that come with either modern scraper planes or the low angle planes that were recently featured in the February 2011 issue of Fine Woodworking (though both of these operate on a very different basis than the traditional toothing planes).
Otherwise, to find one of these old ones, haunt the antique tool shows. Hunt the Web. I found my personal one in England in far better condition than I ever hoped. It’s a beauty and the other guys in here borrow it frequently (and I watch them like a hawk with it).
I hope this has not been overly long, but also useful and informative for everyone out there.
Oh, one last thing: yes, they hand-sawed the veneer back then, 3/32 to 1/16 inch. But that’s for another posting in the future.