Hayn has just introduced a rigging insulator that has a 'failsafe' feature.
If the insulating portion fails, the fitting stays together at full
strength. It will loosen a bit, and you will have to tighten your
turnbuckle, but it doesn't come apart. I haven't seen these yet, but their
other fittings are very high quality. You can see the new insulator at
http://www.hayn.com/marine/rigging/insulator.html. This may take away some
of your riggers frowns.

Rusty O