Buy a couple of packs. If you use your boat regularly, they'll start
peeling after a couple of years. Still probably better than
penetrating the sail, however. I've used them for a dozen years.
If you do want to use yarn, the holes can be made with or without
heat. The hot method is hard to control -- the hole may end up bigger
than needed -- but is acceptable. Otherwise use a (cold) needle to
pull through the yarn, carefully inserting the pointy end so as to
split no (or a minimal number of) threads. The latter is easier than
it sounds.
Regards,
Bill Combs
WWP 19 #439 (Aug 1987)
"Ursa Minor"
Fort Walton Beach FL
ttursine@gnt.net