Welcome to OB Doug4!!! I'm sorry I can't help you with your problem. I've never seen that before. I'm sure others will help you out on that. Is it on more than one plant? When did it start? That may help others help you better. You will love it here, everyone is so nice and helpful! Good luck!
I wish I could help you out, but I just don't know for sure what your orchids have.
I've got a phal in the same condition as your first photo shows. I pulled off 2 leaves - I'm just hopeing it doesn't continue to spread.
I wish I could be of more help! I would keep them away from your other orchids to be on the safe side.