Krenov-style Shelves (page 1 of 3)
The following pages show how I built my Krenov-style shelves. Thanks to my wife Andrea for taking such good photos of me at work.
Other Woodworking pages:
I start this project by cutting the two sides from the best wood I have. These are the pieces that will show the most, so I want to get good figure and color. I also cut them about 1/16" oversized in all dimensions so I could plane the edges down, making them very smooth.
Here I'm using my Steve Knight jointer to square up and smooth the sides of the shelves. I've got both pieces lined up and clamped in my side vise. After hitting the sides with the jointer, I make a couple passes with my smoother and they're like glass. After getting both long edges to match, I square up the end grain using the smoother (yep -- a Steve Knight smoother set really fine will slice the end grain perfectly). Note that when I say "square" I mean I'm making both sides match, rather than that I'm making the corners exactly 90°.
Next, I use my marking gauge to mark the position of the mortises. This needs to be done on both sides, and on each side piece. I do each set on all the pieces and sides so I can leave the tool at the same position, insuring they are all in the same place.
Now the hard part -- cutting the mortises. This photograph shows me starting the mortise by cutting the sides with a 1" bevel chisel. I use three chisels for cutting the mortise: a 3/8" and 1" bevel chisel for the initial cutting and to remove the first layer of wood from the mortise, and a 3/8" mortising chisel to chop out the bulk of the wood. On the mortises that run perpendicular to the grain, I use a 1/2" mortising chisel to chop out the wood. First I mark the edges of the mortise by laying the 1" bevel chisel in the grooves cut by the marking tool and lightly striking the handle with my small mallet (as shown above). Then I use the 3/8" bevel chisel to remove the first 1/8" (give or take) of the mortise. This gives me a nice straight edge to lay my mortising chisel against for hogging out most of the wood.
Now I'm pounding out the wood using my mortising chisel. On the mortises that run parallel to the grain (like the one above), I orient the chisel perpendicular to the grain and chop along the long axis of the mortise. The other mortises (the four mortises in each side piece for the shelves) are cut with a 1/2" mortising chisel, but this time I have to make four smaller mortises, each one cut along the short axis of the mortise. This is necessary because the chisel has to be cutting across the grain to keep from splitting the wood.
Throughout this process it's really important to keep your chisels sharp -- especially the mortising chisels. I use a Japanese water stone with 1,000 and 6,000 grit sides. A couple passes on each side (bevel and back) between each mortise and you'll get a much smoother sidewall.
Here you can see a mortise on the left that I chopped with a relatively dull mortising chisel and one on the right chopped with a sharper one. Both could be cleaner, but I'm new at this! Check out the great heartwood pattern in this Alaskan birch!
After chopping all the way across the mortise with the chisel, it's time to clear out the waste by turning the chisel over and using it to cut and lever out the chunks that have been released. In this step you have to be very careful to keep the edges of the chisel away from the edges of the side walls of the mortise or you'll pop out little pieces in the face of the piece of wood. This was especially tricky in the heartwood of this birch because the grain is so tight.
Not that I wouldn know anything about this (DAMHINT!), but if the board you're pounding on isn't completely flat, it's possible to crack it under the strain of the mortising. In my case, I gently opened up the crack, squeezed in as much glue as I could get in there, and then glued it up as shown above. After the glue dried, I hit it with a plane and then a scraper, and now the crack is invisible!
Once I've cut the mortise about half way through on one side, I repeat the process on the other side. When the two halves come close to meeting in the middle, chop carefully so the wood fibers are cut rather than pulled out.
After I've gotten most of the material out, I used a small bevel chisel to lightly pare the walls of the mortise, cleaning up any high or rough spots left by the mortising chisel. I also used a file to smooth the walls -- just be sure to apply force in a direction that will break out the fibers on the inner sides of the shelves because these surfaces will be behind the shelves themselves.
Now that the mortises have been cut, it's time to plane away the marks from the mortising gauge and the dings in the surfaces from mortising. In my case the side pieces were slightly cupped, so I planed away the high spots, making both sides flat. This is important because the ends of the shelves need to butt perfectly against the side walls. In these plans there's no dado to hide construction errors or warped wood. The photograph above shows my smoothing plane taking fluffy shavings from the edge of the board.
A little scraping with a hand held scraper removes all the remaining plane marks, and really brings out the shine in the figure of the wood. Although it's hard to tell in this photograph, the scraper is sharp enough that it's cutting little tiny shavings.