We have rarely used hard wax release systems in the past 20 years, occasionally using TR and mirror glaze in this time. We moved away from hard wax systems many years ago and over to the Chemlease liquid sealers and release systems. I have no issue with any of the products mentioned however we have just manufactured some boat hulls from a customer mould that had seen better days. The release system chosen by us in this instance was Mold Magic by Grignard.