Butt the second bottom panel labeled B against the first.
Make sure the plastic sheeting does not bunch up between the two panels when you butt one against the other.
Ensure a snug fit.
Secure the second bottom panel in place driving the screws into and through the temporary work surfaces.
When the epoxy squeezes out that means there are no air pockets. A solid joint.
Remove and reserve the excess epoxy.
Set the lap labeled B between the red lines.
When we epoxy the lap in place, it will be about 1/8" in from both edges.
Secure the lap with the temporary screws. Ensure a snug fit.
Use excess filler to create a smooth sloped surface along the edges of the lap.
Remove all excess filler along the ends of the lap. We need a filler free surface at the two ends of the lap.
Some people say use acetone and wipe away unneeded epoxy. DO NOT. Acetone is harsh on plywood.
Here is a big time and labor saver. Take time here to remove excess filler.
Cured filler is harder than rock hard and a bear to sand or remove. So take time to remove all excess epoxy.
I always tell everyone check three times for excess filler.
Leave bottom B fastened in place on the temporary work surfaces and allow the marine epoxy to cure for 7 days with temps above 65 degrees.
After 7 days remove all fasteners.
With a 4" hand grinder remove any excess filler that we missed.
With 80 grit sandpaper and a good random orbit sander, smooth any rough filler.
Drill, remove any excess epoxy or filler that gets into any stitch holes.
The forward edge of the lap is very close to a line of stitch holes that run side to side.
Remove, drill out, all cured excess epoxy that may be in those stitch holes.
Never sand plywood. Sand epoxy and filler.
Later we will barrier coat the deck, deck support, and four bench seat parts.
Save your temporary work surfaces to use when barrier coating those parts.