Originally Posted by capta
I've seen 1/8th inch and larger s/s cotter key heads bent over and wedged into the turnbuckle; I don't see how the welding rod would do much to stop the turning on bigger boats.
The open cavity type turnbuckle with a divider between top and bottom has the welding wire running from the shroud end to the chainplate end and it runs from one cavity into the next (see earlier post with pics)
Given that the chainplate side can't turn, only one part of the assembly turns, the shroud end and that means that the welding wire will go tight - there isn't an awful lot of pressure on the turnbuckle to turn so it doesn't take a huge effort to stop it. And to pull a piece of 316 SS TIG wire straight when bent like shown takes a very considerable effort.
Having said all that, there doesn't seem to be any comment in this thread on the concept of simply putting a lock nut above/below the turnbuckle. That way it is neat, no snagging, easy to undo and will never come loose (assuming it is properly tightened) and it also provides an instant reference as to where the turnbuckle was before you started undoing it. I have mine like this.