Prior to application surfaces should be free from oil, grease or any other contaminates that might be present. When using on a GRP surface, the area should be abraded and then cleaned with acetone before bonding. This is especially prevalent when the GRP is completely cured or has wax based resins.
The product should be mixed thoroughly with a standard GRP catalyst with a flat bladed implement. This will ensure a thorough mix before application. Sanding can be started after 20-30 minutes of application and curing.
A 2% mixing ratio will give you a working time of 4-6 minutes.