Here's what blown shims look like. The right rear had two blown shims on the compression side which allowed gross oil flow and thus no damping. I hit a hole on the way home Monday night. I know I cursed a bit on that one. :) It must have bottomed out as the marker o-ring was up inside the bump stop.

The reason for the blown shims was the impact from the hole, but it probably has something to do with how I built them. I had the largest shim (1.35") with a thickness of 0.004 and the rest on top if it (1.2, 1.05. 0.9, 0.75) with a thickness of 0.006. Take a look at the beautiful photos. The cracks on the two shims lined up with one of the ports on the piston. The edge was just sheared right off!

Learning the hard way! Sure glad I can just rebuilt these things when needed.
The cracks lined up when installedShim Stack - bad design on compression.Right front shim has damage tooThe hole that caused damage was filled by the time I came back the next day!