Here is a blog post I punched out last night. Busy debarking staves recently and had some personal revelations about how to go about it. It was a big enough improvement in my method of debarking that it moved me to write this article. Thought I would share here. Hope you enjoy and I look forward to the feedback from this great community.
The Virtues of a Dull Blade: Stave DebarkingOften times, a bowyer is faced with the task of removing bark from a stave in a manner that leaves the wood underneath pristine and unviolated. Nicks, dings, scrapes and cuts are not wanted; we are talking about the integrity of a bow here! One simple way to accomplish this is to cut the wood in spring or early summer when the "sap is up". During this time, the vascular cambium is growing fast and is full of water, allowing the bark to be peeled off quite easily. Leaving a wet and naked beautiful sapwood back, a perfect natural back to the eventual bow. This method of green bark peeling has its benefits and own unique considerations, but as far as removing the green bark, there really isn't anything to it, simply work up the edge and peel; it often comes off in one continuous sheet* but this post is about another method of removing bark, or really another task altogether, removing bark from a dried stave. By dry stave, I mean one that was cut and seasoned with the bark on. This same bark that once would have peeled off with ease, becomes glued down fast and tight to the stave. There are various reasons why we end up with seasoned bark on staves, and I wont try to explain them here, instead we will stick to explaining how to remove this dried on bark while maintaining the bow's integrity and our own dignity.
Removing bark from a green stave is easy. Removing bark from a dry stave can be difficult, frustrating and potentially waste you a great deal of time in the form of a bow that eventually breaks. But don't despair, there is a way to make debarking dry staves easy, enjoyable and re-assuring. As you might have guessed, this is where the dull blade comes in, specifically, the dull drawknife blade. It is common knowledge in bowyer communities that a dull drawknife is a tool well-suited to the task of drawknifing. I myself have known that a drawknife is what you use to debark staves for quite some time, but it wasn't until recently that I truly realized the importance of the dullness of the blade. Might sound a bit trivial, but what I have discovered for myself is that there is a great spectrum of "dull", just as there are various levels of sharpness, and for debarking a stave, the dullness makes all the difference.
In the past, I have used scrapers and dull drawknives to debark dry staves, but to no avail a little nick or cut would happen hear and there, usually around the tiny little bumps we call pin knots. While these don't spell death to your bow by any means, they can add up in the bowyers mind and move him to back the bow with rawhide or overbuild the bow a bit. Not the end of the world, but an overbuilt bow and a great performing bow are often at odds; and rawhide has its place, but using it as a safety net for any bow that has a few nicks and scrapes isn't very satisfying.
Using a scraper, such as a cabinet scraper works well enough to remove the bark, but it requires lots of force to be applied with the muscles of the wrist and hand. A scraper requires lots of passes to cover the radiused back of a crowned stave as the microplane edge of the scraper cuts through the bark and only pulls up bark where it contacts bark. A scraper does leave tiny nicks in the back, often at the bumps of pin knots. And a scraper requires frequent maintenance to keep a good edge. In short, the scraper is adequate but not ideal. I used the scraper often for the task of debarking even though it was tedious and time consuming because when I used a dull drawknife I simply butchered the back of a bow, destining it to be backed. My failure was in the misunderstanding of "dull" drawknife. I thought a dull drawknife was one you had used for a long time and was in need of a good sharpening. That type of draw-knife was too unwieldy; it would work great when used cautiously, but all it took was one bad move, one moment of inattention, and there I was, spitting into the pile of bark shavings cursing at the tool. So maybe this dull drawknife wasn't dull enough. I will try an older, much neglected drawknife, one that is pitted and nicked up from laying alongside other metal tools, one that is completely dull. But this type of drawknife would require that I learn where the nicks are in the blade and avoid them as they would act as little gouges, leaving trails of minor grain tearing. And as dull as this neglected blade was, it was still capable of diving into the lumps and bumps on the back, requiring extra caution to be used. In short, using a dull drawknife to debark a stave cleanly just wasn't working for me.
Finally, I had the Ah-Ha moment. I recently took a day to resharpen a number of hand-tools. I was looking over a small collection of drawknives, quite satisfied with the freshly honed blades, when I thought, what if I put as much care into dulling the blade as I do for sharpening the blade. So I grabbed a coarse stone, and with some excitement at the prospects, took the freshly sharpened drawknife to the stone and made several passes flipping the blade over and back, increasing the angle with successive passes. Then moved to a finer stone and repeated, steepening the angle ever more. It goes rather quickly to dull a blade compared to sharpening, as you are not forming a burr, rather you are working to avoid forming a burr. While it required little time, I gave it the attention and thought that I would give to sharpening a blade and was rewarded with an absolutely beautifully dulled blade. Not every woodworkers dream I know, but this was it, I knew it was the ticket to debarking before I ever touched it to a stave. And when I grabbed a stick of plum and started scrapping the bark, it was everything I could have asked for and so much more. Suddenly, I had the right tool for the job, and what a great feeling that is!
I have enjoyed debarking several more staves (including the cascara stave pictured below) since dulling this drawknife and was so excited about its effectiveness that I had to write this blog post. I hope you find the joy of a properly dulled drawknife and making your own big discoveries in bow-making.
Thanks for playing along, Carson Brown at Echo Archery
Debarking a Cascara (Rhamnus purshiana) stave with a finely dulled drawknife. Note: Cascara bark (Cascara Segrada: 'Sacred bark', Spanish) is a very effective laxative. Collecting the inner-bark shavings in catch bucket.
* Don't toss your bark! Fold into the shape of a quiver or strip it into sections and weave a basket, or add some to your home pharmacy! Inner bark often contains the highest levels of alkaloids in a plant, some of which are harmful and some of which are extremely effective at treating ailments (most are either, depending on the dosage). Do your research thoroughly before self-medicating with plant medicines.
