I am in the process of refitting a santana 22 that will be used on the
san francisco bay, and will be replacing the standing rigging. The
upper and lower shrouds on each side attach to one chainplate. This
chainplate is located about 18" inboard of the beam, passes through
the cabintop, and is throughbolted to the main bulkhead.

That's all the background, now the problem. I have the chainplates
out, and have found an area of pitting in the stainless (grade
unknown) that is about 1" wide and 2 1/2" tall, with a few small
isolated pits outside of this area. The pits range from barely a
pinhole with almost no depth, to nearly 1/16" diam by nearly 1/16"
deep. All of the pitting is in the area where the plate passes
through the deck, and there is evidence on the bulkhead of water
getting through the deck seal.
The plate is 2" wide, 1/4" thick, and about 18" long. the shrouds
attached are 5/32" upper and 3/16" lower. The boat is about 35 years
old, but the original chainplates from Schock were 1/4" aluminum
plate, and I don't know how far back the stainless plates were put in.

I have gotten three opinions on whether the pitting is a big deal or
not:

1. YES, it's a big deal, the pitting will continue and likely extends
beyond what is visible now. Replace the plates immediately.

2. No, it's insignificant, the plate is way, way, way oversized and a
little pitting won't hurt a bit. You could lift the boat (2600 lbs
unloaded) with a plate half that size.

3. Probably not. Just paint the area of the plate that will be
sealed off from the atmosphere before reinstalling to prevent further
pitting.

The machine shop offering the third opinion also said that they could
fabricate two new chainplates for $200 us.

Relative to the cost of things on this boat, $200 is a large sum and I
don't want to throw it away on servicable parts, but I also don't want
to suffer a dramatic failure out on the bay.

In the realm of peace of mind, my wife / co-owner was present to hear
the first and most troubling opinion, but not the other more calming
opinions.

any thoughts?

thanks,
Joe