kyle wrote:

When I cut the piece of rotten plywood out from th eboat, then cut a
fresh piece in the exact size.. what do I do first?

1) I fiberglass/epoxy it the 4 coats (seal, bond, fill, finish -- are
all of these needed for what i'm doing??) -- both sides & edges
2) do I need to create any butt-joints to mesh with other sides of
plywood still mounted to stringers?
3) apply a thick coat of sikaflex to the stringer, then lay the glassed
piece down / joint it


My answers are based on replacing the entire sole, not just part of it.

You fit the plywood, then glass it totally to encapsulate it, then
finally fit it using the SikaFlex 291.

Finally, you come back and seal the sole to hull joint with a layer of
boat tape.

If you have butt joints in the plywood, seal them with a layer of
DB-170, say 8" wide, on both sides, then come back and finish glassing
the plywood.

The alternate is to use 2 layers of plywood, say 3/8" thick, spacing
the butt joints so they are covered.

Have fun.

Lew