Back Plate Preparation

Now we start working with the back plate.

1. Thickness sand the back to about .070” thick. We mostly take it off of the inside of the back and run the outside just one time to give it a nice sanding.

2.Take the half-outside Plexiglas template and draw the centerline and the outline of the uke on the inside of the back plate with a pencil.

3. Make a pencil mark where the narrowest place on the uke is (at waist) and the widest place (lower bout). Mike has a clear Plexiglas template which he made which is about 6” x 12” with a red center line marked on it and two holes at the top (for hanging?). He places the red center line of the template over the centerline of the uke, lines the top of it to the narrow waist and then draws a horizontal line across the uke to indicate where the top brace will be. Do the same for the “widest part of uke” mark.

4. Cut two braces out of whatever brace material you want. Mine is spruce. Cut it the same length as the outline of the uke.

5. Mike takes a plastic template he has made which is about ½ “tall x 12” in length. It is tapered from the ½” top down to nothing at the end. So basically, it is a gentle curve. He places the brace material up to it and draws a line with a pencil to give the brace a nice arch. This line is to give him a reference to how much he is taking off at the belt sander.

6. So, take the brace to the belt sander and sand down a nice arch on the two braces. Like I said in #5, it doesn’t need to be down to the pencil line it just needs to be a nice symmetrical arch. You decide on how much of an arch you want.

7. Get center brace material and glue it down onto the center line of the uke back making sure you have left enough room for the head and tail blocks. Place a long caul over it and clamp in go-bar deck. Take out after about 10 minutes.

8. Run back plate through thickness sander to refine back brace.

9.Bevel edges of back center brace with a small plane and then finish sand with 3M block sander or other type of hand-block sander.

10. Lay horizontal braces over the center brace and mark with a pencil where they intersect. On the bandsaw notch out between the lines on the horizontal braces where the back brace will come in contact.

11. Glue horizontal braces on the back with two small Quick-Grip clamps at the ends with 3 cam clamps in between for the top brace and 5 cam clamps for the lower brace.

12. After the glue has dried you can carve the braces as the soundboard braces were done.

13. Put back plate on box (soundboard, sides and kerfing) and line up the centerlines and up to the outlines at the top and bottom. Mark where the braces stick out of the sides. This is where you will notch the kerfing so that the back lies flat the sides for glue up.

14.After you have made sure the back lies flat it is ready to “box up”, gluing the back to the soundboard and sides. Place soundboard and sides into the holding jig and clamp onto table. Put a bead of glue onto the kerfing and head and tail blocks. Take the back and line it up to the centerline at the tail and place a small Quick-Grip clamp to position. Take another Quick-grip clamp and position the top centerline. After the centerline is lined up clamp a couple of cam clamps at the tail block and at the head block. The small Quick-Grip clamps are taken off. Put maybe two more cam clamps at the sides of the lower bout and two at the upper bout.

15. Take off from the table and placed whole jig on the floor to continue to clamp all the way around the uke. Be careful to place clamps only where the sides are underneath the clamp and carefully tighten.