I'm planning to replace all the standing rigging on my Westerly Berwick (32ft ketch) in the coming months, and with the eventual not-too-distant plan to do some very extensive cruising (trans-Atlantic, and maybe alot further, perhaps all the way around).
C.f.
http://www.westerly-owners.co.uk/boat_berwick_31.php
I'm planning on replacing the old SS rigging with 7x7 galvanized with liverpool splices (so I can avoid surprise failure and easily see the condition of the rigging, albeit with the additional regular maintenance that comes with galvanized).
I've been talking with a well respected rigger in the UK about some hands-on training doing the splicing at their workshop (I have your book, though there's nothing like an expert checking one's work, especially given where I plan to take the boat), and they noted that 8mm is the smallest that good quality 7x7 galvanized is available in. So to go that route, I'd need to go with 8mm all around.
Not clear why 8mm is the smallest good quality available. The rigger says that what's available in smaller sizes does not have as good galvanization and will rust within two years. Any opinion there?
Taking what I've been told at face value, for the main stays, I'm (ignorantly) assuming that 8mm would be fine, as they are 6.5mm now, and I'm happy to go up a size, especially since I'm changing from SS to galvanized. But the mizzen shrouds are notably smaller (I think around 4-5mm, though I haven't measured them).
What would the implications be if I went with 8mm for all of the standing rigging, both main and mizzen?
Thanks.