EcrosTechWiki | Woodworking / Recipe for Purple Lover's Coaster

Ingredients (Makes Two Coasters)

One piece of purpleheart, ¼" thick by about 8" long by at the very least least 2¾" wide, preferably more, both long edges straight and parallel.
One piece of wenge, ¼" thick by about 8" long by at the very least least 1 3/32" wide, preferably more, both long edges straight and parallel.
One piece of maple, ¼" thick by about 8" long by something like an inch wide, both long edges straight and parallel.
General Finishes Enduro-Var urethane (or similar) to finish.
1/16" thick pressure sensitive cork sheet (or dots, or similar) for underside.

Instructions

Referring to the photograph, the strips of wood are numbered 1 to 9 from left to right. One and nine are purpleheart, three, five and seven are wenge, the even numbers are maple (or whatever species you choose).

Cut the purpleheart longways into two unequal pieces, 1 and 9. To reproduce the design exactly, make one 7/8" wider than the other. If you start with a piece 2¾" wide and your saw kerf is 3/32", you'll end up with pieces 1 49/64" and 57/64" wide and the coaster will be 3 7/8" wide without trimming. If you start with a wider piece, you can trim the final thing to size.
Cut two narrow strips, 3 and 7, from the wenge, each 5/64" wide.
Without moving the rip fence, cut all four strips from the maple, again each 5/64" wide. The rest of the maple can go back into stock, but you need something to hold onto while cutting these narrow strips.
If you started with 1 3/32" of wenge and your saw kerf is 3/32", then you'll have ¾" left for strip 5. Otherwise, cut a strip of this width and put any remainder back in stock.
Glue up all nine strips, either at the same time or in stages if you prefer. Make sure to keep the ends reasonably well aligned as you'll only have about 1/16" to trim at each end (assuming you're starting with pieces 8" long).
Optionally, if you find this easier, start the sanding before separating the two coasters. Maybe this is the time to remove the dried glue squeeze-out. I would be running the whole thing through my drum sander at this point, stepping down the grit to 220, which is the finest I have.
Cut the panel across exactly in half, measuring from the shortest strip at each end.
Trim each half to the finished coaster length of 3 7/8". If you started with strips 8" long you'll have about 1/16" to trim from each. 7 7/8" is the realistic minimum length of the starting strips with a 3/32" saw kerf and you'll have to be very, very careful to align the ends for the glue-up. Of course, you could always make the coaster a bit smaller.
Trim the width of the coaster to match the length, taking the same amount off each side (or not, if you don't think it matters).
Decide which face of each coaster will be the top, i.e. which has the better appearance. If both faces are perfect, good job, but if anything has gone wrong maybe you can hide it on the bottom.
Fit your router with a 45° chamfer / follower bit. Adjust it to cut only about 1/16" deep in the workpiece. Run a piece of scrap through to check the depth of the bevel or start shallow and then adjust for a deeper second cut. With the coaster top-side down on the router table, run all four edges across the bit. Cut the ends first (across the grain of the strips) and then cutting with the grain along the sides will clean up any minor corner chips. The depth of the bevel will be according to your preference, but I think that it looks best penetrating no more than one third of the way down the edge.
Complete sanding flat and smooth. You can neglect the bottom, but include the sides and bevels. Don't sand more than necessary to the point that the bevels become round-overs.
Apply the urethane finish according to the manufacturer's instructions. Three coats should be fine.
Apply the 1/16" cork sheet to the bottom, leaving a margin of about 1/8" all the way around.

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