Hard to know where to start, there's loads of potential causes, especially with 8 plies. Can you post a photo of the part and the mould?

Just pulled part from Mold awfulll pinholes,new material.using high temperature Molds.every ply debaulked used standard cure cycle really pissed hours of work only to be binned.the is heat sheild 8plys thick is it me or are other users having similar problems.