The plans call for 1/8" vinyl-coated cable. Has anyone used just 3/16" galvanized (or stainless) instead?
i used 1/8 stainless for my vacationer. after two years of being moored for 4-5 months each season and constantly exposed and severely tested by storms which whipped the boat back and forth constantly for days at a time, theyve showed no signs of stress. i wouldnt use galvanized, tho. the few bits of hardware ive used in galvanized have already have to been replaced. of course a trailer-sailor would probably get much more life out of galvanized hardware.
I found some second hand 3/16" coated clothes line at a garage sale, it lasted 3 months of my first season. I was in a 10 knot blow and the stays snapped one after another until I had just the forstay left. Don't economize on this area, I replaced them with 1/8" stainless coated, with a 1200 lb rating. One of the best investments I made.
One thing you may want to consider if you are going to go to a larger headsail and for protection of your mainsail as well. Chafing and rubbing against the shrouds can discolor your sails and sheets. You may want to have coated wire to prevent that and 1/8" stainless would be the best choice for a Weekender or install shroud covers to prevent the main from rubbing on the bare wire. (Ace Hardware carries a 1/8" vinyl coated stainless that is more affordable than the "Marine" store stock.) These are slit full length sections of small diameter PVC tubing that goes over the shrouds. Comes in short lengths so you don't need to cover the entire length of the shroud. Just the portion that comes in contact with the main when running downwind