Originally Posted by Blue Stocking
Bobstay fittings are usually in line with bobstay. Any pull at downward angle will place shear forces on fastenings, won't it?...
Most bobstay's I've seen have the lower fittings such that the bolts are in sheer
for bobstay loads, which is usually the strongest way. Putting the anchor loads on there, even via a snubber, makes a lot of sense, but puts those bolts in tension
, which usually isn't as strong as sheer. So I'm glad to hear Gil's planning to beef those bolts up first. You really don't want those bolts to fail.
For your snubber, use some stretchy 3-strand nylon, not double-braid Dacron. The Dacron will be stronger, but you really want the stretch, to relieve snatch on the ground tackle. Our first bridle was 5/8" double-braid & we blew it apart (with guests on board
) in a surgy anchorage. Now we use 1/2" 3-strand nylon for our bridle, with a thimble tied in the middle shackled to a chain-hook. I have to replace the bridle every 4 years or so as it gets a lot of UV damage, but I don't want to go bigger or I'll lose my stretch.
Lots of boats put plastic hose around their bobstay to reduce chafe. We do the same around our cap-shrouds (which are also our back-stays) to reduce chafe when our (battened) mainsail
lies against the shrouds in following winds. This works VERY well. When we bought Ocelot, the 3/4" battens were almost cut through by the cap-shrouds, but since we put the plastic on (10 years ago) we've had essentially no damage to the battens. The batten pockets have small holes where they get pinched between batten & shroud
, but that's all. I'd think it would work on a bobstay as well.
If you don't want to take the bobstay off, you might get some rigid plastic pipe & slit one side on a table saw. Then you can stretch it open & slide it over your bobstay. This is actually what we do with our caps - .85" od plastic pipe stretched over 14mm (.55") dyform. We used French exterior water-pipe & it's been fine for 10 years now.