On average, how thick is the putty fairing layer over the mat on a
strip planked hull? I guess it may depend on whether vacuum bags were
used (that's a question too - what's the general consensus on vacuum
bagging a hull?; what are the gains 'cos it looks like loads of
work?).

I'm just trying to cut the molds from the designers lofting templates
and I want to know how much to reduce the size of them by, to allow
for the overall hull thickness. But I also need to order the right
amount of filler too.

The glass suppliers have told me that two layers of 500g m² mat of uni
directional rovings laid at 90° add up to about 0.75mm after layup -
sorry about the metric measurements for the Americans, I haven't a
clue how many ounces/yd² that is - which sounds negiligble to me, but
I have read somewhere of around 3mm or just over 1/8 inch may be
fairing filler.

This sounds a lot to me (after my many attempts at plastering over
defects, I feel that the more you put on, the worse things get). It
seems to me that if easily sanded fairing is used it must be a bit
soft, so would the minimum necessary be used?

I'm talking epoxy here BTW, and I'm assuming that I will make a
reasonable job of laying up the mat .............. hmmm, I can hear
the gods of Famous and Doomed Last Words stirring from their slumber
already.......

TTFN
Pete