Finishing pond liner on tubs

Hello. Me again. I think I'm just going to cut lose and start asking
ALL my pondy questions now. :-) It's more fun than perfecting killfiles.

I've got my pond liner for the tubs - 20 mil EPDM. I've got one filed
with the liner perfectly flat on the bottom and folded neatly on the
sides but I'm not sure how to finish off the edge of the tub. I got
some 1/2" galvanized roofing nails figuring they'd be good for outdoor
use. Do I tack the liner to the rim of the tub and trim it so none
hangs over? Or is it better to fold it over a bit and tack it to the
outside of the tub?

I think tacking it to the rim would be neater but I wanted to be sure
that will work OK.

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__ Elaine T __
__' http://eethomp.com/fish.html '__