A back for a not-so-square case

Back_1

In an earlier post I admitted that my dresser case was not square when the glue dried.  I’m not exactly sure how out it is because I get different numbers when I measure different ways, but it’s out of square between 1/4 and 1/8 inch over the diagonal.  At this point I could have built a back that is also out of square, but I thought that would be too difficult.  Imagine building with angles of 90.5 deg.  Silliness.  Instead, I decided to build an oversized frame and panel back that could be planed to fit.

Back_2

For a frame and panel back, it is nice to use quartersawn stock for the frame.  It is easy to make narrow quartersawn stock, all you need is thick, flatsawn material.  Here I am flattening one side of a cedar 4×4 post.  Once I have two flat and perpendicular sides, I run it through my bandsaw to get 3/4 inch thick quartersawn stock.  It is quick work with a bandsaw.

Back_3 Back_4

Once I had my frame stock cut to the correct lengths, I started the joinery.  First I plowed grooves, just like the rails and runners.  Then I used my bandsaw to cut the open mortise and tenon joints at the corners of the frame.  I decided to drawbore the corners so that clamps would not be required to glue the frame.  Drill the hole in the mortised board first, then use it to mark the spot on the matching tenon.  Notice that I had some scrap wood in the mortise to prevent blow-out of the grain inside the mortice.  Usually, the hole in the tenon is offset toward the shoulder of the tenon board, but this one is offset in two directions and I found it really helpful to keep Woodwork Joints (Charles Hayward) in my off hand for reference.  FYI – That book never leaves my shop.  

Back_5

With all of the components cut to size and all the joinery trial fitted, I laid everything out for glueup.  You can see my panels are 1/4 inch ply which saves time, materials, and weight (compared to solid wood panels).

Back_6

This is why I should have used one pin per joint.  I thought that one pin did not look like enough holding power.  Silly me, I should have known to trust Mr. Hayward without question.

Back_8

After the back was assembled, I fit the back panel in place.  I made the back 1/2 inch longer than the dresser.  I did this because I wanted to be able to trim some off each side to fit the square back into the non-square hole.  I expected to remove material from the bottom left and top right of the edges – and that is exactly what was needed.  I put the back in place and marked the corners where wood needed to be removed.  I fit the left side first, then the right.

Back_7

Removing wood from the end of a panel or long board requires creativity.  Here I clamped the back panel to the front of my bench and stood on my sawbench.  I have stood on my benchtop when needed.  Fit one side at a time.

Back_9

Keep checking and planing until you get a nice (somewhat) snug fit between the rebates on the sides.  Why a snug fit?  Because the back will be glued in place.  In case you think that would be a problem for wood movement, I did my research first.  I found an article in a Fine Woodworking Magazine article written by Christian Becksvoort.  He built a dresser with similar joinery and he glued on a frame and panel back.  Since he literally wrote the book on wood movement, I figured it was ok to glue it.

Back_10

Once I was happy with the fit of the back panel in the case I cleaned up that damage I showed earlier and flattened out a few rough spots.  It is the back, so I didn’t got over the top with smoothing.  Next I glued the back in the case and moved my attention to the base, but that will be the subject of another post.

Bob Jones

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One thought on “A back for a not-so-square case

  1. Pingback: Recap errors and how I “fixed” them | The Christian Tool Cabinet

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