Part of the tree which was cut for the Split-top Roubo Workbench had a beautiful Y in it. I ripped a book matched straight edge on one side and had to glue a little bark back on. It was a bit of a surprise that the bark stayed on the rest of the sides considering it was the ash-borer beetle that prematurely killed this tree. I had to hand plan and sanded the entire bench as it would not fit thru the 15" planer. This had proven very difficult due to the highly figured, multi-directional wood grain. Tear-out was frequent, so a majority of the work was done on the belt sander.
I had never used dutchmen before (also called bow-ties) in any work. I thought it would look nice to have a highly contrasting material like black walnut. The idea of dutchmen is to prevent further splitting of the cracks. The opposing grain and "V" shaped inserts are meant to pull the opposing forces the crack naturally creates and prevent it from further separation. The slab is just under 8/4 (2") and the dutchmen are about 5/4 (1.25") deep.
The surfaces were all finished with General Finishes Exterior 450 water based poly. One brushed coat and 4 sprayed created a pretty nice finish. It's likely I put a few more on in the near future to make it a little smoother.