I was working on the printed VW drag body I bought. I got it sanded smooth ( lots of sanding ). I also was able to prime it . I wanted to add some exhaust dumps to the body so I marked it and then out to the drill press. I started out with a small pilot hole but it wasn't long before I heard a "crack" ! I got about a one inch split out from the hole. Nothing I can't repair but I did not know how fragile this stuff was.