> but there must be a rule
>which states what the maximum grade of paper to use to give the best result
>i.e. you should use 80 Grit advised by Europa on layups before future bonding
>but it always seems a bit coarse to me. I only use 120 Grit for roughing up an
>already preexisting glass surface. How do you get 41.4% increase in surface
>area?
>Tony Renshaw
I once watched a demo at Sun n Fun by an air force expert, (might have been
navy) who said that he'd done tests anmd found to his surprise that fine
abrasive gave the best results. In fact the one he rated best was 3M
Scotbrite soft pads.
Makes a certain amount of sense to me, because it's soft it conforms to the
substrate and abrades the whole surface, whereas 80 grit is rigid and does
not.
Someone else mentioned research that says it is new surface, with low
surface energy that gives good wetting and that may well be the key. Don't
forget the Boeing water test either.
Graham
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