This additive is to be mixed with polyester resin for use in a “hot coat” or “sanding coat”.
It eliminates the surface tackiness caused when polyester resin cures and hardens, allowing it to be easily sanded.
5% wax-in-styrene should be thoroughly mixed in to polyester resin before the catalyst is added. Make sure to shake the wax-in-styrene well first, as the paraffin wax and the styrene separate when left for a while.
Any further resin coats done after a hot coat (eg. a gloss coat) need to be sanded before application to ensure proper adhesion.
This 100ml quantity of wax-in-styrene is enough for 2kg of polyester resin
Have you considered fibreglass cloth?