This week the project went from 2D to 3D when I added the joinery for the top, bottom, and rear panels that I have been working on the past 8 weeks. I am still many weeks away from gluing things together, so you will still need to use your imagination to picture what the piece will finally look like. On the bright side, when the time comes the project is going to transform from a pile of parts to a nearly completed piece with a few quick glue ups.
The top and bottom of the cabinet are joined to the rear panels with a series of dowels. The dowels provide additional strength to the joint as well as alignment of the curved panels in relation to the doors and other cabinet parts. The top and bottom panels are 3/4" and 5/8" thick respectively and the dowel holes are carefully (and with trepidation) drilled to within 1/8" of breaking through the veneer on the other side.
The key to doweling is to make sure you drill the holes for the dowels are in the right spots on the two parts that you are joining together and that the holes that you drill are pretty darn close to being straight and true. If the holes do not align then the parts will not align, and if the holes are not straight and true then you will not be able to bring the joint together. The Krenov School way of accomplishing this is to build a doweling jig out of hardwood and use it to guide a drill bit as you drill the two sides of the joint.
The doweling jig for these joints is made out of a piece of maple. I used a template to cut the jig to precisely match the profile of the rear panels which also matches a portion of the curves on the top and bottom panels. I glued a series of small strips of wood to the edge of the jig that are used to register the jig against the edge of the panels. The jig is attached to the piece being drilled with a few screws and a drill press or an electric drill (with the help of a drill block) are used to transfer the holes from the jig to the workpiece. The photographs show the jig in place on the flat panel and the resulting holes on the curved panel. The drill block is also pictured in the lower left corner of the curved panel photograph.
After the holes are drilled, a couple of the dowels are inserted and the pieces are put together to find out if the whole operation was a success or if you need to plug the holes and try again. In this case it was relatively successful!
Step A complete! I now have two panels and a top and bottom that mostly fit together but I have not yet figured out how I want to join the left and right rear panels together and what kind of detail I want running down the spine of the cabinet. Since I am in the habit of kicking most decisions down the road on this project I decided to build a mating piece with two groves in it that I can use later to stick in my desired detail (in software engineering terms, I just slipped some feature creep into the project and sold it to the project manager as an extensible feature).
The spine is held into position by a few locating dowels that run through the spine and into the rear edge of each panel. I used the spine as the doweling jig to transfer the holes between the two panels. Next challenge to consider was clamping. The only feasible option that I could come up with was to glue temporary clamping blocks on to the interior edges of the panels and use those to pinch the edges together and bring the spine joint home. I really did not want to add a bunch of glue blocks to my beautifully prepared birch veneers on the interior of the cabinet and I do not know yet how painful it will be to remove them. I am sure it will all be just fine.
It will still be a very long time before things get glued together permanently as I have come to accept that I need to build and fit the interior shelves and drawers while the carcass of the cabinet is still in pieces and I can drill holes and trace curves.
To top off a challenging but productive week, I roughed out some hinges for the doors. More about those in another blog post but here are pictures.