Created a quick basic how to video for making sugar shims. There are a lot of different ways to create sugar shims but basically they are made from 1x4s.
You will need a drill, saw, at least 1 1/2″ exterior rated screws, and a square. The square is used to help get a square cut and to check the overall squareness of the shim after everything is together.
There are lots of different ways to make these shims but the quickest and easiest method is just but-joints and glue and screw. Cut two 1x4s 19 7/8″ which will be the long sides and cut two 14 3/4″. The overall length must be 19 7/8 x 16 1/4″ so these measurements will work for that outside length. It is best to cut them with a miter saw but you can use a circular saw and use a speed square to help keep the cut straight. This is very important to keep the shim square. You MUST pre-drill the wood for the screws because soft woods like pine will split this close to the ends. Use a countersink bit which will cut out enough room for the screw head. Add titebond 3 glue to the ends and screw them together.
If you have a table and clamps, clamping the boards to the table to hold them in place and square while inserting the screws definitely helps. Once all four corners are done check the squareness of the corners. Also check to see if the shim lays flat. If needed you can slightly twist the shims if they need to lay flat. After the glue dries, check the flatness again and trim or sand if needed. A slight gap is ok but large gaps should be repaired.
My preferred method for building them is using rabbet joints because it helps keep the shim square. However, I still prefer screws because of the added strength. Box joints, pocket holes, and many other methods are available as well.
