Posted for Ken Welter <rotary.coot@verizon.net>:

   I have been having Performance coatings Auburn WA do my rotor coating and would suggest them, however I make aluminum pieces that fit tight in the apex grooves and I mask the sides off so they are ready to shoot just for my piece of mind that they wont get mucked up however they do coating for Atkins and Hayes a so they are probably setup and know about the grooves.
  Ken Welter