To minimize potential cupping, we decided to make the top by gluing two pieces of 1×6 together rather than using a solid board. Choose a straight piece of 1×6 with a sharp, clean edge. Cut the pieces long and trim the top to length after you glue the two parts together. For pro tips on gluing boards edge-to-edge, see “Edge Gluing Boards” . Justin and Jackson cut biscuit slots in the sides of the two 1x6s to help hold them in alignment while installing the clamps. Glue and clamp the two 1x6s. Then let the glue set up about 30 minutes before routing the edge (Photo 10).
Start by arranging all the parts on your work surface. Justin used a flux brush to spread the glue in the slots, and onto the biscuits after they were installed. Any small brush will work, though. When you have everything assembled, install clamps to hold the sides tight to the shelves while the glue dries. Check by using a framing square or by measuring diagonally from opposite corners to make sure the bookcase is square. Adjust it if needed. Then tighten the clamps. This is a good time to take a break while you let the glue dry for about an hour.
Thickness planer. A thickness planer is used to fix surfaces of imperfect wood. If you are picking up less than perfect wood from the lumberyard, wood with some surface defects, a planer will let you fix that wood in the quickest time. A thickness planer pays for itself quick as it allows you to buy cheaper wood that doesn’t have perfect surfaces and fix it yourself. Be careful though. You loose wood during planing. So the remaining amount of wood still has to be worth the price you paid for it.