My first mould is a casting mould and once finished I successfully cast my first part with it. I used an acrylic resin filled with aluminium hydroxide and the mould was prepared with Easy-Lease. The surface wasn't mirror polished but pretty shiny. The part released well from the mould however I noticed that the mould surface seems to have been affected in some way by the resin as it is satin now and in some places it looks like some residue is sticking to it. I guess there must be a compatibility issue, is it more likely between the resin and Easy-Lease or between the resin and the gelcoat and can anything be done about it?

Kind regards
Martin

What is the mould made with?

This is the same mould that I had the fisheye problem with. I just noticed though that the product is listed as topcoat not gelcoat, I didn't pay too much attention to that as it is just what I had. I don't know but guess that even though it is still an epoxy product it might be less optimized for compatibility in this kind of use.

Yes, totally unsuitable. Lots of solvents in topcoats, which cause issues like this.

Also explains your fisheye issues, as topcoats are just way way way too thin to resist separation, and have no thixotropic properties.