Aircooled -- I've shot up to 6 coats at a time with HOK and PPG Global clears with little or no problems. My booth is my garage and everytime I shoot I have to clean it out and set it up - Kind-of a pain, so if I have a job that should be double dipped in clear because of the art and paint edge I'll do it all at once to save time - It's easier for me that way. The only problems I've ever had were solvent pops because of a 90+ degree temp and a few sags. It seems to me that the more coats you put on over the recommended amount, the more time for flashing is required. I average 15min flash time when I start the first coat and end up around 25-30min after coat #5 -- But you can do it - just get a few good mags to read!!! --- BTW - Maybe your client was thinking Laquer clear in which 8 coats would be normal --- Bones!~