Chair project: backrest

first step is to make the mold for the backrest that will be later press in a vacuum bag. The mold is made out of sandwiched 5/8" particle board cut to different lengths to give the rest its concave shape.For the veneer to have a good glue up the mold needs to be perfectly smooth... bring on the bondo.I defined the shape with a wood rasp and sanded it with 120 and 220 grit.