Chigiritsugi used in Wood Joinery
....’chigiritsugi’ is the eastern Japanese name, while here in the west we prefer; ‘spline’, ‘flying dutchman’ and ‘butterfly’ joint….and then also I may have missed or forgotten a name.
While starting out here I will just insert an observation that I have used and noted over time in the study of western and eastern thought in woodworking and ‘wood joinery’.
Understanding wood goes a great way in helping to explain the why’s of using a particular joint over another and also how and why the construction may vary from east to west. Here in the west we have had an abundance of hardwood so our joinery has followed the wood strength of using those hardwoods. Then if we shift our view east, Japan developed joinery that is used, in their more abundance of softwoods. If one wants to understand this more, then one can look at how the mortise and tenon joint has developed in the thought and practice of woodworking by west and east.
Understanding something of timber framing and the joints that are used in the construction of post and beam can go a long way into understanding the way’s and how’s of ‘wood joinery’. In China there was abundant stone and so this was used to a large extent in the architectural construction of temples and buildings and wood joinery being used more in furniture. In Japanese architecture, the mortise and tenon joint was developed and used both in temple construction and furniture, while in the west, (Europe) we used our hardwoods for timber framing and the mortise and tenon was refined some more. When the early settlers came to America, most of the carpenters who came were former carpenters of the many ships that ran the high seas and so when building now on dry land, they still added their flair of shipwright woodworking into the homes and barns of New England….again along with the mortise and tenon.
Ah yes, the ‘mortise and tenon’ joint, so many variations, so many flavors to choose from. Next there is also that which is found in architectural design, the ever present spiritual and philosophic thought and then the tradition of using what ‘is at hand’. From east to west, the design and proper execution of style is so very subtle, that unless one knows what to look for, one may miss the smallest details that makes ‘wood joinery’ so long lasting and full of ‘wood art’.
I will point out one such detail that involves the understanding of the ‘mortise and tenon’ joint and how it varies in it’s makeup from east to west. With the abundance of softwood in Japan, the ‘mortise and tenon’ joint was developed with the idea of using the character of softwood to increase the strength of this joint, in the use of ‘compression’. Therefore if one were to examine a tenon, you would see that the end of the tenon has been tapered, so that upon inserting the tenon into the mortise, the joint is squeezed home and the use of ‘compression’ is drawn upon to increase the strength of the joint. While in the west here, using the hardwoods, we made the ends of the tenons all straight, no taper and hammered the tenon on home into the mortise. I remember when I climbed out of the box of western thinking and went east, however as time passed I also found that to be just an-other box and so climbing out of that box also….well, lets just say that when one is out of the box or boxes, they are then free to use all box’s!
Moving forward and onward we will now fast forward to yesterday evening in my barn. I thought that I might post an example of one of many joints that can be used in the joining and stabilizing of cracks, splits and two boards. The ‘chigiritsugi’ or ‘butterfly’ joint is one such among many others that can be used, ‘koshikake-ari-tsugi, (lap dovetail joint) chigiri-tsugi….and on and on. And so I decided to show the result of how a butterfly joint can fit and look when it is fitted into two boards of plywood. I hand cut this one in just a matter of about an hour, that is from set up, to hammering the joint into place and then yes, the finishing took me longer. I might add that I hand cut most all off my woodworking joints, as I have found this way to be just about as fast and even in some cases faster then setting up machines to do the job. As I said, this ‘one’ took about an hour, but when I’m in the flow, I could have cut four of them in about the same time. I might mention that another difference in joinery thinking between east and west is that here in the west we start to the inside of the line and then proceed to the line to clean up the joint, while in the eastern way of thinking the cut is made on the line….or you might say first cut is the clean up also. I tend to like this way of thinking since I have found that when you leave no room for error, you will develop a way of working the wood that is without error….another way of saying, finished and completed mindset all in in one.
One of the best ways to understand ‘wood joinery’, is to end conversation and asking about the how’s with others, close the books and head out to the workspace and get the ‘feel of the wood’. One never knows what they can do until they have done it! I find that one of the best ways to practice ‘wood joinery’ is to use scraps of plywood that I have saved from projects and these make great excuses to practice upon.
So having said all that, lets look at some pictures, and remember….YOU CAN DO THIS!!!
....finished product….and remember this is done very fast and by hand….
....I cut the mortise out with a 1/2 inch mortise chisel right on the line of the two boards, cleaned up the inside with a 3/8 inch chisel, placed a piece of paper over the mortise and ran a pencil over the cut to get my shape for the butterfly….
....next I found a scrap piece of birch which I had rived earlier for the Greene and Greene entry, spit this one again and laying the paper pattern on top, I penciled in the image. Next I chiseled this area out and got ready for inserting….this I did by using a wooden mallet and taping the butterfly into place….
....next comes the finishing which actually takes longer then the cutting….I used a 2 lb. cut of Garnett red shellac, four coats which I also wet sanded in between the third and fourth coats, ( de-waxed shellac) and then also between coats, I will rub into the wood and any small cracks fine wood dust, which I save from my sanding jobs, for this express purpose. Remember what I have so often stated, I use it all….this wood dust is from a walnut bench….and then I also then applied fine gloss fast dry oil poly….two coats….
....close up of the walnut wood dust….
....more sanding, wet sanding with the poly and I will also mix in the dust with the wood, till have a slurry going on the wood I am sanding….another picture of the finished product….and this one has now also been buffed to the starting of a high sheen with #0000 steel wool….
....and here is a picture of the tools used….
....and then if I had not of ended my day doing this example of an ‘chigiritsugi’ in process, I would have been putting in sanding time on this piece of up and coming ‘wood art’....
Next to come, I will give some more thoughts on how to secure the underside of those two pieces of plywood….this is an example of what can be done, and though small in size, the same style can be used on bigger pieces.
”....all is yours, take what you will, only use all that you take, and so i am….”
-- --frank, NH, http://rusticwoodart.tumblr.com/