Is Your Handplane Tuned? Acacia melanoxylon Knows
One of the best things about getting older has been the fact that I can now do more woodworking tasks “by feel” than “by eye.”
As my already-crappy eyesight has become dulled by middle age, I’ve found that my other senses – particularly my sense of touch – have become heightened. I cannot always see a knife line, but I can feel it with my saw, chisel or plane.
Same goes with the dreaded tear-out – I can feel it coming through the tote and knob of my handplane before I see it in a shaving or on the wood itself. This feedback allows me to correct things during my stroke – usually rotating the plane’s body slightly – to improve the feedback.
I also can feel when a board is flat or clean – I don’t have to inspect every square centimeter (unless I want to).
You don’t, however, have to endure 20 years of woodworking to develop this intuition. The shortcut is to simply get a chunk of Tasmanian blackwood (Acacia melanoxylon) and see if you can plane it without tearing it.
Toolmaker Colen Clenton gave me a hunk of it while I was in Australia this month, and it’s from the same board that David Charlesworth’s chunk of blackwood comes from. It is nasty stuff, and this particular chunk has bark inclusions, plus sapwood, heartwood and crazy grain. Fun!
This week I decided to see how my planes measure up and record what settings on the tool will produce a clean surface. The results were not surprising. To get clean cuts, you need some combination of the following properties.
1. Sharp iron. Sharp fixes everything.
2. Fine cut. The thinner the shaving, the less tearing.
3. High pitch. Planes that are pitched at 55° or higher have an easier time with blackwood.
4. A close-set chipbreaker. If the plane has a chipbreaker, set it a hair’s width from the edge. A chipbreaker isn’t a must-have item. I have several planes without breakers that could handle the blackwood easily using the above three characteristics. But if you have a breaker, you might as well use it.
5. Tight mouth. Closing the mouth tight seems to help, though not as much as the top three characteristics.
6. Stop skewing. Skewing the tool lowers your effective cutting angle, which can increase tearing. Plane the grain directly 90° to the grain.
Oh, and all of the above tips are for naught if your plane does not have a well-bedded iron and a reasonably flat sole.
The Doomsday Board
Oh, this might be a good place to mention that I do own one board that is completely unplaneable. It’s a piece of perfectly straight-grained Douglas fir. John Economaki of Bridge City Tool Works sent it to me a couple years ago and suggested I give it a go.
So I took a single stroke on its face, and my plane iron was trashed – it looked like a toothed iron for veneer work.
I took a close look at the board. It looked normal in every way. I resharpened my iron and tried a different face. Again, my iron looked jagged, like a bread knife, after only one stroke.
What’s the deal?
Economaki explained that the board was from a tree that was near Mount St. Helens during its 1980 eruption. The wood was completely impregnated with tiny bits of volcanic crap. And those little bits of volcanic junk were trashing my plane.
The funny thing is that I didn’t just throw the board out. I keep it in the lumber rack in case I ever get into a planing contest that is unwinnable.
— Christopher Schwarz
Hey, want to set up a handplane so it can plane blackwood? A good place to start is with my new DVD “Super-tune a Handplane.” It goes through all the steps required to selecting an old tool and tuning it up using household products (nor surface grinders or milling machines). Check it out here.