The Evolving Dynamic of Rip Sawing

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Rip sawing is one of those things that even devoted hand tool enthusiasts try to avoid. Compared to cross grain cuts they require more stamina, more positive force and control of the saw, and more attention to work holding. But how does one learn to use a saw?  A while back I decided to do all of my cross-cutting by hand, figuring I needed the practice. It still seemed like too much work to rip my stock to size. And its true, the joined panel work for my fuigo build has taken a tremendous amount of time to saw by hand, about 30 hours, maybe more. The intent is not to see how quickly the work can be accomplished so much as to understand and develop the fine motor control that accurate sawing demands.

As a student of music I spent many years of my life working to understand the whole body interaction that is expressed when playing a musical instrument. To a casual observer it may look like most of the work is being accomplished by the movement of the fingers, but that is just the end point of a motion which starts in the spine from the neck. So when I hold a saw I approach it trying to develop a technique, a relation between my body and the saw borne of practice. And too that end it really requires working the muscles to the point of fatigue, where things start to become a bit sloppy and you may finally notice muscle interactions that before were not consciously apprehensible.

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This is a taste of the work at hand, 20″ wide douglas fir paneling in both 1/2″ (finished dimension) and 1/4″, resawn from 2×12. The best I can do from construction grade lumber to obtain vertical grain  comes from ripping the sides of a flat-sawn  2×12″.  Additionally if you’re really feeling like sawing you can rip the middle of the flat-sawn board into 1.5″ strips and re-join for vertical grain orientation. Its a seriously tedious way to make a panel, but you get a lot of practice with the saw.

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I recently bought a copy of Iichi Hayashi’s “Reading Trees” (“Read Tree” If you’re looking for a copy on amazon). Its very frustrating to have a book in Japanese full of, from what can be seen in the illustrations, excellent information that is just out of my grasp. For example, take a look at this image, notice the thickness of the silk-line for his sumitsubo marking on the highly concave surface of the log. It probably does a better job to have such a thick line, more stored energy to push into the contours and get a clear line. Haha, look at the size of the karuko pin that secures the line! This is marking the rip cut of a master sawyer on a piece of log that is probably worth more than my truck, where no deviation in layout from a flat plane is acceptable. Needless to say, I’m working to fit more hours into the day for learning Japanese. I simply must be able to read this book.

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At the opposite extreme from the previous photo is my own humble work, but with very thin pieces. The kerf of my 350mm rip kataba I used to saw these pieces is about 1/16″, fat for your average ryoba saw kerf.  In relation to the thickness of the material being cut I would much rather be using my 210mm saw. The problem arises with this kiln dried lumber. To start with, Douglas Fir is already a mobile and reactive wood. Add to that a fast kiln time (that didn’t even remove moisture to average environmental equilibrium) and you have a piece of wood that is stressed on the outside from the kiln.

So you plane a face flat and mark with kebiki for the cut. Even assuming a theoretical perfect planar cut the wood cups about 1mm or 2mm, while the saw is in the cut! Your average joinery saw simply does not have enough set to cut a straight line with wood experiencing such an obvious release of tension.  In this I mean the ratio of kerf to plate thickness. You could try opening the kerf heavily with a wedge, but that leads to its own problems. Save the fine saws with ultra-thin kerf for ripping your best carefully seasoned and stable wood.

 

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My jack plane on edge is brilliant at squaring the edge of the pieces to be joined. I’ve used this same rail on the side of my planing beam with push style western planes and it is much easier with the Japanese plane.

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I flatten and condition the surface of my planing beam before any major project, so the alignment between the two faces must be maintained parallel.

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Every other piece for the panel is edge jointed on the opposite face  so that any small deviation from square cancels out. It becomes really important with these thin panels, where a small deviation will show up as a cupped panel that you don’t have enough wood left to make flat. In this case my glue up is at 3/8″ for a finished thickness of 1/4″. My clamps want to cup the panel in the direction of the beam, so I’m careful to alternate the clamping. Sometimes despite your best efforts the panel wants to join up with a bit of cup and in that case you can use the clamp to straighten it out. Another interesting example of where the problem is the solution, no?

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Here I’m using my 270mm ryoba to rip the vertical grain sides from my 2x board. Oh, I made a sumishashi, awesomeness! Though…I cut it from laminate bamboo flooring. Cutting a board like this is a microcosm of what ripping a log is like. The angles of the saw to the work, the angle of the work to your body, very familiar.

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One of the things that became apparent to me recently was how much of a drunken idiot my non dominant hand is. All this time I’m sawing with two hands thinking I had control. Really its the right hand desperately trying to control the wild oscillations of the left. To improve, I’ve been sawing with only my non dominant hand. I reach a point of fatigue very quickly, but there is no other good way to develop conscious muscle control. When you return to sawing with both hands your brain suddenly gives much more mind to what the left hand is doing.

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Let us ignore my lame excuse of the wood moving as the reasoning for the crappy quality of the cut on this particular board, an eight inch re-saw for the piston head of the fuigo. The pattern of ridges left from switching sides of the cut is an obvious indication of some kind of bias in my technique. In this case (and in most of my ripping) I have a tendency to lean to the left while sawing, pulling the saw to the left as well. To compensate I have been subconsciously twisting the saw back to the right. The effect of a twisted saw plate in the cut is a cupped cut face on the left side, and ridges alternating as you switch sides to cut down the line.  I only recently noticed, and it wasn’t so much from reading the surface quality of the resultant cut so much as working to the point of fatigue where the pattern of improper tension became very exaggerated in my body and my hands.

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In a discussion with Jason he mentioned the effect of gullet clogging on cut drift as well and it forced me to take a fresh look at my saw. I’ve put hundreds of hours on this saw now and never filed back the primary bevels, only hitting a secondary bevel on the top of the tooth. I seriously never noticed just how small the gullets were becoming. Its embarrassing to show this, but I’m sure we can all relate to becoming complacent with the condition of a tool. Cutting down the saw teeth forced me to notice how the set of the teeth was also at play. With the longer tooth length I get a better curve to the tooth when setting, and I think it results in less heat being imparted to the cutting edge (and thus a saw that stays sharp longer). Thanks Jason!

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Once I started to correct my body’s tendency to lean over while ripping the surfaces of my rips became much, much better. No leaning over meant no twisting of my saw hand, and kerfs where I could actually get the saw plate to balance evenly. I try to remember, the saw is flat, it WANTS to cut straight if you can line your body up with the cut. The saw has only one proper planar orientation in the cut, it is your body that must orient to the saw, never the saw to the cut. I’m eager to apply what I have learned to my maebiki-oga. Happy Sawing!

5 thoughts on “The Evolving Dynamic of Rip Sawing”

  1. Gabe, the force of the saw is strong in you. Very deep description of the process, I totally need to try this.

    Sometimes I also try to saw with my non dominant hand, but haven’t done it till the point of exhaustion. It works better when I let the saw to make the job, no force at all, just try to keep a constant pace.

    Gullet depth. This is how I understand the difference between japanese and western saws. Your little grooving planes that each tooth is can take a finite size “shaving” off the wood each time it passes. The length of this shaving is given by the vertical size of the tooth. By deepening the teeth, you create more space to let the saw do it’s job at its own pleasure. All this is dependent on your stroke length, the size of the wood you are cutting and the material of the saw. I tend to imagine japanese technologies as always balancing two opposing principles, and moving on the line of the perfect balance. Under this light I can see the metate filing the teeth exactly for the type of wood, cut and even body of the sawyer to create this magical dance.

    By the way, I don’t know if I’ve written this in my blog, but do you find any difference depending on the order you file the facets? I do vertical first, then bevel, this way I feel the saws has more bite.

    1. Thanks! I agree with what you say about the saw balancing two opposing principles. You see it quite readily when it comes to optimizing tooth shape for the wood. I’ve been making my rip teeth ever more aggressive in forward rake trying to find the right balance between how easily the saw bites and how well the edge holds. It is true that when the saw is very sharp the best technique comes from using almost no force on the cutting edges. Then there is the minimum of tension in your hands and arms and you can feel the alignment of the saw in the kerf very discreetly. That said I do find myself pressing the cut trying to speed the work of the saw, especially with these wide re-saw cuts where you have more teeth in use, less force per unit area. I’m trying to find the balance where you cut as fast as possible without bending the plate in the cut.

      My normal filing is bevel first, then vertical. I hadn’t thought about it making a difference, I will definitely try your approach.

  2. Love this. I’ve been fantasizing about doing a rip cut apprenticeship, basically spending months strictly rip cutting wood and lumber and learning from a master. Of course I don’t know if anything like that actually exists, but… for some reason it appeals to me. Well, I guess I can just practice at home, too.

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