I had a question from a reader about the bookcases discussed in Cordelia's Nursery and shown completed in Cordelia's Nursery: Part II. The IKEA Billy bookcases in the 41" height are not meant to used as a corner solution, but I devised a way to make it work by creating a top out of birch ply. It's actually a fairly simple IKEA-hack, despite what may seem at first glance as intimidating directions (see below). If you have a program such as Google SketchUp (bonus - it's free!), it makes the hack that much easier.
You will need:
Plywood of your choice (1/2" to 3/4" thick)
A board of the same species of wood as the ply
Circular saw guide and clamps
Drill and bit to match the dowels
Finish Nails and corresponding Nail Punch
Small wood screws
Miter Saw or Miter Box and Japanese Back Saw
Finish of your choice (I used urethane)
1. Lay out a plan view of you bookcases
2. Add a half inch on all sides except for the back
3. Divide that new shape into sections no longer than 8' (which is the max. length of a sheet of ply)
4. Try to do this so that the grain runs parallel with the front of each bookcase
5. Dimension the SketchUp sections and lay them out on the ply.
6. Using a circular saw and guide, cut the sections out.
7. Lay your pieces out as they would be when installed, but upside down. Be sure to not scratch the good side.
8. Using a pencil, draw three small lines across each joint. equally spaced to each other and the ends of the joint. These will help us align the dowels.
9. Align the dowel jig to each of the lines you just drew and drill holes into the ends of the boards to accept the dowels.
10. Prepare to glue. Lay two scrap wood pieces approximately 2" x 1/2" x 12" parallel to one of the joints. Make sure they are set back about a quarter of an inch on each side of said joint. Also, make sure that you have at least two clamps that are wide enough to get around both of these pieces.
11. Screw these two pieces to the BOTTOM of the two boards. Make sure the screws you use are not long enough to penetrate the finished face or you'll ruin the pretty side.
12. Apply glue to the edges of each board and too the dowels you'll be inserting. Attach the two boards together and place at least two clamps onto the screwed-on scrap pieces to hold them together.
13. Use a damp cloth to clean up any excess glue.
14. If you have additional scrap wood and clamps you can repeat steps 10-13 for all the joints while your first joint dries. If not, wait for it to dry per the glue manufacturer's recommendation before doing the next joint.
15. Use a table saw to cut down the birch board to a series of strips approximately 3/8" x 1". Because the pieces are so thin I recommend you use a feather board to keep the wood against the fence and a push rod.
16. Use the miter saw to cut the edge strips to size, making sure the corners are properly mitered together.
17. I pre-measured the location of the finish nails on the edging and pre-drove them for each piece.
18. Apply glue to the ply and edge piece and hold together. Drive the nails in to hold the edging in place. Use the Nail Punch to recess the heads.
I used a random orbital sander and 80 grit to make sure the edging was flush to the ply. Then I worked up to 120 and 220 before urethaning. I put on four coats, sanding in between per the manufacturer's recommendation. I left the nail heads exposed. If you wish, you can use some wood filler to fill in the recesses left by the Nail Punch. Also, our walls were straight enough that I didn't want to scribe the top to them, but that is something to consider if you want the fit to be really, really tight. If you are going to scribe, I would make the boards a bit wider to account for the material you're going to eventually cut away. Good luck!