is 35 years old. To the best of my knowledge, chainplates have never been done.
I noticed rust weeping from the bolts for the two backstay chainplates which are attached to the inside of the transom inside the lazarette and are fibreglassed over.
So I bit the bullet and started to cut away the covering fibreglass to have a looksee. There was water
inside behind the fibreglass both top and bottom. -Main corrosion
was around the top of the plate and the water
was quite black looking.
So have now totally removed one plate and am working on the other.
The plate is approx 9.8mm thick and the two holding bolts on each plate are approx 9.1mm diameter. Plates were only polished for the exposed top. The rigging
is 5/16 wire with ⅝ pin toggles on the turnbuckles. The transom is a good ½ inch thick.
My question is to do with the appropriate replacement. I am going to get two new 316 plates made up.
1. Is the existing plate thickness sufficient? I read if you have a ⅝ toggle pin you should be looking at ½ inch thick chainplate?
I don't like the idea of enclosing the new ones like the previous design and want to get away from that. Locating them on the outside of the transom will mean some mods around the toe rail which I am not keen on either.
So I was going to locate them back where they were, just not encase in fibreglass. Would put butyl tape between the plates and the transom to seal and butyl tape to seal at deck
with seal covers.
2. Should I have the new plates made up with the two "cross plates" as before or do as as a single flat bar piece?
I am thinking these cross pieces are there to either add surface area in contact with the transom and add extra holding but if not encased, am wondering if really necessary.
3. Should I add a couple or three more chainplate bolts?
The two bolts seems a bit light on to me. Would probably go up a size also for the bolts
4. Any comments or problems I should watch for with this job and am i doing the right thing to replace?
Thx in advance.