The bottom edge of the seatback was tapered 45 degrees using the table saw.
Using an electric hand saw, the slots were cut out of both side edges of the seatback.
Visualizing how the bulkhead will be inclined at 45 degrees in the cockpit, this angle was cut for the slots on both side edges using an exacto knife, hack saw, and hack saw blade. The exacto knife was used to carve the foam. The hacksaw was used to cut fiberglass and foam, and the hack saw blade was used to cut fiberglass where the hacksaw itself was too big to be used.
All corners on the backside of the seatback were rounded where the side will be glassed. The rounding was done with the scrap foam pieces and some sandpaper.
