Cissing Problem


As some of you know I have been striving to replicate urushi techniques with West System marine epoxy, using resin 105 with catalyst 205.   My results to this point have been very encouraging.  I ran into a problem today that I hope someone will know the solution.
Up to this point I was sailing along using pigments and dyes in the layers of epoxy to render the painted finish I desired, and abraded between each application with dry 3M Tri-m-ite (white) silicon carbide paper.  No problem.
The final (?) coating of clear epoxy was applied today, and I got catastrophic cissing (or beading-up) of the coating.  There was no contamination of the surface that I know of.  I was punctilious with my work and preparations.  I always use a clean unwaxed paper cup to mix, a clean tongue depressor to stir, and a clean brush that is dedicated to this task and always cleaned repeatedly with acetone after every use.
The only thing different this time was that I had switched to 3M Tri-M-ite 600 wet or dry silicon carbide paper, the black stuff, for the final coat preparations.  I used water as the lubricant, wiped the surface with a new lint-free blue paper towel, followed by another wiping with another clean towel soaked with acetone to degrease the surface.  And yet, the beading renders the surface a failure.  Given this as the only variable, I’m thinking it pretty much has to the place to start looking for the source of the problem.
Anybody see anything obviously wrong?