TYPICAL SECOND 3/8 SHEET CLAMP UP

A sheet of 3/8 marine plywood is selected. Most sheets are flat, but some have slight curve bias or "set", making it easier to use the sheet one side of the boat than the other. Before the planking process my bulwark was marked showing locations of frames, scuppers, chainplate blocking.
The location of the frames on the bottom are easy to locate because there is no planking on the bottom. Once a sheet is selected (see scarf layout and cutting scarfs) scarfs are laid out and cut on each end, but on opposite sides of sheet.
Next the sheet is clamped in place and chaulk lines are snapped for the frames, and bulwark, outer clamp, deck, scuppers, chainplate blocks are located as well - you don't want to be looking for locations or screwing into voids while the epoxy is going off. Now remove new sheet to horizontal surface.
Two batches of Epoxy are simultaneously mixed, one to be squigged on backside of new sheet, the other to be rolled on first layer that is on the boat. Next a thickened epoxy batch is mixed, and applied to the scarf areas, bulwark area, and chine area. By thickened I mean enough wood flour so that the epoxy won't fall off or run to much.
Now remount the sheet and clamp the ends.
I use a couple of vertical 2x4's clamped top and bottom, clamped a little ways in from each end. The I clamp to the bulwark across the top, Then I screw into the frames with temporary clamping screws (with washer or plywood square for greater surface) to make sure that the two surfaces are in contact. I am especially careful in the chine area. The scarfed ends require special care - next photo.