On the OP's question, smallest piece first will be stronger
(assuming a good bond). Depends on what you want. You can
also put down more than 3 layers wet-on-wet, I've done five
or six at a time (using slow set resin) and it works just
fine. The prep work is the key.


And don't forget to put a sheet of plastic between the core and resin
if you're working next to the core. (the foam reacts with the epoxy
and gasses, leaving voids).


???

Isn't the point to bond the core to the surface? If you're
getting that much reaction & gas, you're doing something wrong.


dog wrote:
This is rather bad advice. In almost all cases, you WANT THE RESIN AND
PATCH TO BOND TO THE CORE. Putting plastic between the core and the
resin leaves a void too, just not one filled with gasses. Most cores DO
NOT react to Epoxy by dissolving and gassing off... especially if the
core is a good end-grain balsa, which it is on the better boats.

Not tostart an argument, but there are many foams to choose
from and some are lighter & stronger than balsa.

... If the
core is not bonded to the repaired area, you have effectively created a
section that is pre-delaminated.

Yeah, that was kind of what I thought too. But you have to
keep in mind, everybody wants something different.

DSK