Re: 3M Marine High Strength Repair Filler
While I am also a 3M fan, I'm more an epoxy fan, especially below the waterline.
A nice epoxy mix with some 407 or 410 filler mixed to the needs of each particular job is as maleable as you need it for each such job, and sands wonderfully. The 410 is awfully light though, only for cosmetic repairs. 407 is someplace between cosmetic and structural.
Bashing about on Lake Ontario and Beyond
"Ariel" '79 Endeavour 32