Hi all 

Either use the original gel coat with some wax add and sand back through the grits to a high finish, or I have had a lot of success using durabuild HHR putty 

Just wondering,

If it is a minor chip or void in the mould, is the addition of a wax additive to the tooling gel coat necessary? Will a vinyl ester tooling gel coat not harden completely?

Thanks in advance,
Jady

Yes you need to use the additive or you could cover the resin with release/flash tape.

Having fixed a mould with the unimold gel coat, results were good but it's really hard work sanding it back!