Yes, it is a good idea to sand before putting the deck onto the hull. However, it is unlikely the end pour is going to pop out if you don't. There is generally enough texture in the ends to provide a decent mechanical bond. A sanded surface would just be better.

: Our epoxy and fiberglass experience prior to boat building was very small, so
: since we're working on our first boat, we've been taking the "mush
: sand after 72 hours" pretty literally. However, there are times when
: that isn't possible (eg. filling the sheer seam where it is our of reach
: or doing the end pours). Does the end pour really help and stick to the
: hull and deck when they were fiberglassed weeks, possibly months :-)
: before? Down in the bow or stern, you can't even reach to wash the blush
: (if any) off. Would an experienced builder have sanded the areas before
: bonding the hull and deck?

: Thanks,

: Tim.