Starting with sealing the clay by brushing it with talcum powder and then spraying it carefully with release, wax or petroleum.
Then adding the gel coat, with 2 % cathalyst, and sprinkle fiberglass on the top when it is partly set.
After the gel coat has set it is time for the fiberglass matt, added in small parts with fiberglass resin with 1% cathalyst. Adding it with a paintbrush, piece by piece, be careful and make sure to avoid airtraps and bubbles.
It is very important to wear protective clothing including respirator and eye protection.
Leaving it to dry over night, to make sure it is completely set when demolding.