I recently purchased a 1967 Cal. Going into the purchase I knew some items would need to be replaced. Specifically the standing rigging. I know that good guality bronze should last a long time. My question is how do I tell if a bronze turnbuckle or the attached fittings are about to fail. I recently used "CLR" to remove any corrosion and ended up with a nice shiny bronze turnbuckle that looks great but how do I know there is''nt some microscopic crack that will send the mast crashing down around me.