Shaker Cupboard: Unique Backboard Arrangement
The backboards on the White Water Shaker cupboard, the cover project on the first-ever Popular Woodworking Magazine (April 2010), gave us all a charge. Why would the maker of the original cupboard construct the back in this manner (see the layout below)? Were the pieces leftover from something or somewhere else? I’m afraid no one will ever know. But if you’re up to the challenge, or just a woodworker that begs to work to the exact dimensions and designs as the original, here’s the scoop on the cupboard’s back.
This arrangement is easy to copy, but the work, while appearing as simple as good layout and accurate cuts, is a bit more demanding. Why? Each of the board’s edges, when the layout lines are connected, is cut at different angles and that causes each end cut to be a different angle.
When I first walked through this build in my head, I figured to cut the boards to the widest width needed per board, mark the narrowest width at one end then make the cut at a band saw staying on the waste side of the line. Then I would clean the cut with my jointer. That all worked fine.
The top and bottom cuts are laid out off the same edge of each board each time , either the left or right edge as you view the boards. A square is all you need to do this. But the task of making the cut is more involved. I had to set the angle for each cut exactly at the layout line or a ragged edge would appear. This would be time consuming and not so easy. Move on to the second attempt, and this is how you should work.
The Correct Method
Cut the pieces for the back about 2″ longer than the final length, then rip them to the final width, the given measurement plus 1/4″. Leave one of the two outer boards wider than required. Mark the second width (don’t forget the extra 1/4″ here as well) 2″from the end at the appropriate point on the board , some of the boards get more narrow at the bottom, and some at the top (this works to our advantage later in the process). Strike a line connecting the two marks, then make the cut at the band saw before truing the edge with a jointer , powered or hand propelled.
Before moving on, arrange the boards as they fit in the back, number the top end of each board and mark an “X” on the tongue edge of each piece. Remember that either the first of the last board, depending on how you wish to work, has only a tongue or only a groove. The inside boards have a tongue on one edge and a groove on the other.
Create the tongue-and-groove joint. Make the fit snug, but easily assembled.
The next step is to bevel the outer board that you cut to size, either #8 or #1, so it fits the groove in the case side, then fit the inside boards in place, according to the numbers. I used pennies to set my joint gap. Arrange the pieces so about 1″ extends over the case top. When all but the last board is positioned, take a measurement from the edge of the last board positioned to the inside edge of the groove in the second case side. Measure at the top edge, then layout that width on your last board. Transfer the waste area measurement to the bottom edge, then rip the last board to its final width and create the bevel to allow the board to slide in the groove.
Next, slide the last board into place and adjust the joint gap as needed. If your back doesn’t reach from side to side, simply tap one of the wider boards toward the middle of the case. Because the boards grow in width, tapping toward the middle of the case increases the overall width. Conversely, if things are too tight, tap a wider board away from the middle decreasing the overall width of your back.
With the individual boards positioned (and joint gap spacers in place), clamp a straightedge flush with the bottom of the upper section, then use a router and pattern bit to bring the boards in line. You can cut the upper edge of your back the same way. With either cut, it’s not easy to completely flush the first or last board in the set because you get too close to the case sides. It’s best to remove the outer boards and complete the cuts away from the cupboard.
When that work is complete, reposition your boards and nail them to the case, one nail per board per shelf , except for the last board , to allow for season changes, although the original had as many as three nails per board.