So I will try to answer all the questions;
Yes 309 is impossible to get here without ordering internationally. 316 is also very much a challenged both need to be imported. I’m no expert in metals or strengths but based on my general understanding over the years and this link
AISI 309 Stainless Steel vs. Annealed AISI 304 :: MakeItFrom.com
I have decided to go for 304 and increase the size to around 19mm almost 30% and do both sides.
I will have to agree to disagree with the tea staining sorry about that.Its a bit like saying all 4 legged animals are dogs in my view. So yes if there is a fracture or crack then you agree you will get tea staining in all probability ( all dogs have 4 legs) but because there is tea staining does not mean its bad or a fracture, but simply oxidization protection ( another words not all for legged animals are dogs). Just my view and I could well be wrrrrrrrrrong.
Yes crevice corrosion could play a part, although clearly the shaft had been machined down from the threaded end at around 16mm on the thread, to the nice polished shaft to around 14mm. So where did the crevice come from initially if not stress crack. So yep the thread at the bottom is bigger than the shaft, which seemed very odd to me. So how did the crevice get there, possibly simply from age and stress.
At the time there was about 14-18knts of true steady beam wind and around 1m sea’s So nothing big and as I was in no hurry I was reefed on the main a little, full overlapping job out.
The gear is produced by Selden.
Yes the post heading probably should be changed, yep I’m told it is actually called D1. Im not sure how to change the heading.
Yes the pictures provided by Annapolis are in fact correct. I looked for any angle issues and yes there is a difference. As this is a production boat to actually correct that would be significant. My guess is the strut would need to tilt probably 4 degrees inward at the top to align perfectly with the stay line from deck to just below cross tree. However un like the J boat issues of past for example, this miss alignment is not transferred to the turnbuckle and the design allows the turnbuckle to move a good 40’ before any pressure would be put on it. There would be some horizontal inward pressure on the deck fitting itself as a result of the angle mismatch. While I agree its not ideal, its not something I will attempt to change. Clearly the deck is reinforced and strong as it took the full load and nothing is visibly wrong.
Yes the rod goes from the bottom of that heavy inverted U bracket, where there are two nuts on 16mm rod, up through a couple of shelves, through a plate set in the deck that the chain plate is bolted too and it goes through the chain plate by about 25mm. The top is not threaded its welded 25mm up each side and 14mm across the top and bottom. Looks good. It broke as it comes out of the chain plate base, and its not welded on the bottom of the chain plate.
With hind sight I have now attributed the blame 50% to ware & tear and 50% to
Waisai–To be dis masted or not–Part 1