Hi Julien,

Thanks for your question.  Yes you can build up the Pattern-Coat Primer in that fashion. You will need to ensure you have your layer thick enough so you won't go through to the wood.  Pattern-Coat Primer is a soft material so will be relatively quick and easy to machine to an exact shape.

Normally the Pattern-Coat is easily worked with simple hand tools and abrasive papers so when machining it, you would be looking for a tool that works with softer materials.  It should be similar to machining a medium density model board.  The exact tool and machining settings are going to be unique to each type of equipment and we recommend following manufacturers recommended settings and tools.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant