Topcoat & Gelcoat- Frequently Asked Questions
The expected coverage of the Standard Polyester Topcoat and Gelcoat is 500g per square metre.
This depends on the type of mould you are trying to make (male or female). In this case it sounds like you need a gelcoat rather than a topcoat. Please refer to our guide on making a mould which will detail the mould making process.
If the area has an old layer of Topcoat which you wish to refresh there is no need to prime the area with a product such as G4 for example. You will, however, need to sand down the area, wipe down with Acetone and reapply a new layer of Topcoat/GRP materials if required.
When applying a topcoat after laminating, apply between 500 and 550g per m². Alternatively, use our Materials Quantity Calculator. For Fibreglass Roofing applications, this should increase to 600g per m².
When applying Gelocat to a mould, apply between 500 and 550g per m². Alternatively, use our Materials Quantity Calculator
Gelcoat is not a finishing coat; it is painted onto moulds/plugs and remains tacky after it cures. Resin and Glass are generally applied on top of the Gelcoat. It forms the hard, smooth shiny surface of the finished article and is usually pigmented. It paints on easily but does not drain from vertical surfaces. Use