As far as replacing standing rigging how far should one go? Should I replace all bolts that hold tangs and the spreaders? Should the spreader fittings be removed to inspect for mast corrosion (my fittings wraps 3/4 of the mast circumference)? Should all fittings that are rivited be removed and new rivets installed?
This is a good question.
Next time I talk to Steve I'll ask. He is working long hours and studying for an ABYC exam so I think I'll give him a few days. Last thing he wants to do is talk shop with his dad after a 12 hour day.
In the mean time I'll bet I can guess based on prior conversations.
If it's coastal, take a really good look, I'm guessing with a magnifying glass, and if you see anything amiss replace the part.
If it is off-shore and the parts are over 10 years old replace it all if you can afford it otherwise pick and choose and take your chances.
Look we all know we take chances every day we drive a car or eat a big Mac.
None of this is news. It would be really easy to spend 200% of our income on insurance. Some of us worry about risk more than others and we all draw the line in a different place. That is not what the intention of this thread is.
The lesson I have learned From Steve and Doug and others is a very limited metallurgical one.
1. Stainless steel as used in sailboat chain plates and other rigging components is a phenomenal material but it can and does deteriorate to the point where it is no longer safe.
2. Often indications of this deterioration can be seen in the form of micro-cracks and pits.
3. Sometimes this deterioration can not be seen because it occurs in hidden places.
4. Sometimes this deterioration can not be seen because of damage by lighting or work hardening.
5. Sometime this deterioration process is accelerated by a design that allows flexing.
6. Sometimes this deterioration is accelerated by improper loading caused by a failure of other parts or improper use or improper tuning.
7. The older a part is the higher the chance it has suffered one of above processes and no longer has its like new strength.
Did I miss anything?
The only thing we have learned, I hope, from this is that we can no longer look at the stainless on the decks of our boats and cavalierly think, "IT'S STAINLESS I DON'T HAVE TO WORRY ABOUT IT".
How often you check it and how often you replace it depends on your tolerance for risk combined with how you sail just like everything else.