Making a Draw Knife with Ben Orford
Having caught the greenwood working bug with an introductory course in early spring I was determined to make my own shave horse to keep at home.
This however got me thinking about which came first the shave horse or the draw knife?
No matter how strong and sharp a draw knife, it is no better than a butter knife if the stock is not held fast for it to be worked on. Likewise a shave horse is all but useless if you do not have any sharp tools to shape the timber to make a shave horse.
You can of course borrow both, including skilled instruction, from many a training school and take home your prized new horse but for me this did not quite seem to complete the circle as I pondered making my own draw knife with which to draw my shaving horse.
Chance would have it that Ben Orford and I were booked on the same course in Herefordshire, he as tutor and me a student which was cancelled at short notice. As we were both at a loose end I challenged Ben to teach me to make a draw knife.
As a master toolmaker Ben was under no illusion that to take a totally unskilled metal worker with a lump of steel and produce a quality tool, in one day, was a tall order. But he rose to the occasion magnificently.
At his modern efficient workshop near Malvern, Ben handed me a piece of spring steel about the size of an average ruler. He explained that we were going to extrude the first 40mm of this bar into tangs which would measure some 200mm when we had finished hammering, a feat I could not comprehend as we started.
The furnace is efficiently gas fired and portable (used by mobile farriers for site visits) though Ben assured me that charcoal and strong bellows can produce the same furnace like temperatures if you wish to try.
With leather gloves and tongs in hand the bar is heated until it glows with a satisfying redness before being removed and the first shoulder marked on the anvils edge
After some three hours of repeated heating and beating the hammer gradually forged the metal bars ends into a long tapers which, with Bens encouragement, guidance and occasional deft swing of the hammer, were straight and true.
Grinding the edge
The drawknife generally has a Scandinavian grind which is one bevel with an angle of about 27 degrees. This is undertaken on a fairly ￼course grind stone which removes metal efficiently and quickly accompanied by dramatic sparks flying in all directions.
Creating the edge is now complete and we move onto honing which is undertaken on a vertical belt sander using a much finer grit to create a smooth bevel and a razor edge.
Hardening, Tempering and Annealing
This is where the science gets really quite heavy as we try to give the tool different characteristics at different parts of the tool. We need a really hard section at the front capable of holding the cutting edge but if you can imagine the forces when you hit a knot, we ￼need a much more elastic metal at the shoulders so that they will not shear.
To achieve these divers needs the blade was heated until cherry red (ready when it losses magnetism) and lowered into a vegetable oil bath for hardening. The tool must enter the oil vertically to ensure even cooling and to stop stresses occurring from one side to the other.
Tempering comes next with the blade heated more gently from the back edge until the metal turns a colour from ‘dark straw to light vermillion’ which indicates its correct state. Further localized heating is undertaken with a torch which is termed painting with heat.
Turning and fitting the handles
The final metalwork is to heat the shoulders and turn the tangs to form the characteristic U shape of the tool, at the same time canting the tangs downward to create a more natural posture when using the tool at the shave horse.
Given more time we would have moved to the more traditional outdoor workshop to turn the handles on the pole lathe, but we were running out of time and I elected to fit a couple of handles that Ben had turned earlier for his own production.
With a little adjustment of the central holes the tangs were driven onto the handles until they were through the handle by 5 mm. A copper washer was fitted and the ends of the tangs peined over to ensure a permanent fit.
Ben is a master at sharpening every sort of tool and quickly has the draw knife up to scratch with a sharp edge, and is keen to see what we have achieved. With a few deft pulls on a fresh log he deems the new tool a success.
It has been nearly 8 years since I spent this day with Ben. I have used my draw knife a great deal and I am constantly delighted that I made it. Although I had some interest before it was truly this experience that got me hooked on green woodwork and the way of life.
The end result from a simple piece of bar to the finished Draw Knife.