Rigging inspections 101

Those of us who keep our boats in freshwater don’t give a second thought about all that rigging wire aloft.  Properly done, a set of rigging on a weekender inland boat will probably last longer than the owner.  A salty coastal cruiser or ocean boat is an entirely different set of problems.
I have, unfortunately been forced to pay heavily for some expert knowledge that I am willing to share for free to my friends who may one day choose to follow in my wake.
Rust is your friend.  It shows you where the failures are.  
You can’t see cracks in binoculars.  You have to clean the rust off and then look through a magnifying glass to find them.
Stainless steel ain’t.  If the metal is deprived of oxygen (air or flowing saltwater) it will rust.  There is no way to seal the swaged area after it is swaged.  Fill the cup with LifeCalk, insert the wire, and then have it swaged.  Don’t listen if they say it won’t work, or they won’t do it.  (They don’t like the idea of goop in their machine) Find someone who will.
304 Stainless is not the same or as corrosion resistant as 316 Stainless.  You want 316.
The rig should be inspected by an expert every 6 years.  As often as you can it should be washed down with clean fresh water either rain or from a hose.  The rig should be expertly inspected every six years. Rinse and repeat as necessary.
Set aside a fund of money that is for maintaining your boat.  You know that the sails, rigging, electronics, and upholstery aren’t going to last past 10-12 years.  Figure up what all that will cost ($15,000-20,000 for a 36-40 footer) divide it by twelve and start saving now so that when the time comes, you don’t squeal or sell your boat because you can’t afford the fixes.  The next guy will just make you come off your price to compensate for the lack of maintenance.  You don’t want to give the boat away, do you!
I pay from $255-225 for a first-class (10-15 years experience, worked for a dealer assembling and commissioning Hunters) rigger to climb and inspect.  It took two guys 2.5 hours to do the job with one aloft and the other inspecting at deck level.  
On TANGO they found cracks all over the rig and bad rust aloft.  They cautioned me not to sail the boat and braced the mast with the jib halyard down the starboard spreaders and the main halyard relieving the strain aft.  
Sure enough, an hour out of Marathon, the starboard upper shroud parted just above an eye fitting at the upper spreader, but the rig stayed in column because of the brace.
I am a believer.