2. The 'core' is often made from scraps of wood and may be laid with who knows how many
: small-medium voids. These voids are a real variable that is hard to
: control or predict in advance. Alhough one possible way (if it wouldn't
: ruin the sheet) would be to pre-soak the sheet and examine for voids. All
: that show up could be repaired from the back before you started building.

Thanks for your comments Joe. My major concern was also the issue of voids and scraps. I have watched softwood plywood being made and understand how you could end up with voids at the most inappropropriate places. Is there a grading system for other plywoods with hardwood exteriors that implies minimal voids and scraps?

grant