Storfidra 25 where are my chainplates?!!

[Yourmomm]

Hi all. So I've been trying to renovate this boat with as light touch as possible, but I fear the time has come to get a but more destructive (something I'm keen to avoid, if possible).

I've checked all over, and cant find any evidence of the chainplates. Obviously they're encapsulated somehow, but the bolt patterns visible directly underneath the shrouds suggest that the shrouds are simply connected a deck-mounted pad-eye, without even a backing plate! Is this even possible?! I assume not, on a boat that's done numerous transatlantics, and sailed to New Zealand, from Denmark....

So, I'm assuming there must be something more substantial, (not visible), buried between the cabin (polyester) liner, and the hull, but there is no other evidence of bolts for such hidden chainplates, either to bulkheads, or to the hull itself. Short of taking a saw to the mahogany lockers, and an angle grinder to the the polyester cabin liner underneath them, to investigate more, is there any knowledge out there of how these chainplates may actually be mounted, so I can minimize my destructive efforts to inspect them?!

Cheers in advance....

Ryan

[Auzzee]

I don't know much about the particular boat, but it appears, from the rudimentary drawings on Sailboatdata that it must have a deck stepped mast. As there appears to be no compression post as such (at least in the photos I can see on the 'net), I assume the load is taken by a beam above the forward bulkhead.


If indeed it is a deck stepped mast, the chain plates need to be more substantial than if it were a keel stepped job. The terminal points seem to be well outboard so, I assume, the bolts either go into a formed longitudinal beam under the deck to hull join, or more likely, there will be a steel 'knee' glassed onto the inside of the hull, generally beneath each cap shroud terminal, and which turns under the deck for the specific purpose of taking the load of the rigging.

Generally this would be mild, rather than stainless steel, and is probably quite large and about 1/4" plate with a small gusset at the turn. If you have your mast installed and the rig tensioned, take a look from close to either end of the boat, along the topsides, to see if there is a small dip in the topsides below the point where the shrouds attach to the deck. This could be the telltale that demonstrates the chain plates are attached to the inside of the hull. In many older boats, the tension on the rigging will deform the hull slightly where the chain plates are physically attached.

The system is quite good providing the attachment point doesn't have cracks around it where water can get in. If you suspect water has got in, there is little option but to operate to make sure there is no serious corrosion...remember a rigging failure will always occur when it is under the most load!

What you may be able to do is to look inside under the turn at the hull-deck joint and see if there is a small ridge or step below and to either side of the on deck attachment points. If there is you may be able to carefully drill a small (say 1/8") hole upward, from the bottom of the ridge or step, to see if any rusty water or other corrosive crap comes out. If not, it's a fair bet the plates have maintained their integrity.

I reiterate, I know nothing of these mighty little boats and I am making suggestions based on my history with mush larger craft. However, I hope you get the problem sorted out without any great difficulty. Please keep us updated on the results. Best wishes.

[Tom Thumb]

Auzzee has it about right. I’ve been working on my Storfidra 25 for about six months and recently replaced the eyebolt/“chain plates”. I increased the diameter of the eye bolts slightly so drilling out the old holes was necessary. What I found was the longitudinal beam that Auzzee referred to. It seamed to be a composite made up of a very dense softwood ply and aluminum, of which a much was apparently used on these boats. I don’t consider this to be a perfect solution but it is what it is. My vessel has been through much so whatever structure designed, worked. As far as longevity, the wood/aluminum composite isn’t perfect so keeping moisture out of the system is critical.

[Yourmomm]

Originally Posted by Tom Thumb

Auzzee has it about right. I’ve been working on my Storfidra 25 for about six months and recently replaced the eyebolt/“chain plates”. I increased the diameter of the eye bolts slightly so drilling out the old holes was necessary. What I found was the longitudinal beam that Auzzee referred to. It seamed to be a composite made up of a very dense softwood ply and aluminum, of which a much was apparently used on these boats. I don’t consider this to be a perfect solution but it is what it is. My vessel has been through much so whatever structure designed, worked. As far as longevity, the wood/aluminum composite isn’t perfect so keeping moisture out of the system is critical.

Yep figured the longitudinal thing in the end. But Aluminium though?! ????? Are you sure?! Not good, if true. I got distracted in the end, attending to more pressing matters (ie damage to bow requiring entire bow rebuild, as well as mast requiring a new support structure)....but both jobs are now almost complete, and I'm returning to the issue of the chainplates soon....

So did you replace yours, or leave them as is? Would be very interested to see the work you've been doing on yours...

[Tom Thumb]

Yes, not thrilled about aluminum but so be it I guess. I think the only solution would be to fashion an actual chainplate that would be bolted to the hull in a traditional fashion. On the positive side, the drilling spoils that came out of the enlarged holes seems fully intact and the boat has been sailed aggressively at times in the recent past...hard to know exactly without major demolition. In general, a lot of aluminum was used in my boat in terms of interior fixtures as well.
Photo is of the new dyneema dux lifelines and lashed deadeyes from Colligo Marine. I'm not using turnbuckles and instead going with Colligo deadeyes with dyneema lashing.

I'm also upgrading some of the electrical system in order to get as much joice as possible from the stock 40 amp alternator.

I'll start another thread and post mosre images as I have them.


http://https://www.instagram.com/p/B3-KihBnY1z/

[Tom Thumb]

I'll start another thread of my Storfidra refit soon. But yes, not thrilled with the aluminum but I'm not ready to shape new chainplates and the drilling spoils from the new eye bolt install seem fully intact. The boat has been sailed hard recent to my purchase of the boat so think it's ok for now. Here's one photo of the new dyneema Dux (Colligo Marine) standing rigging and lifelines. I'm not using turnbuckles and am using Colligo deadeyes and lanyards.

https://www.instagram.com/p/B3-KihBnY1z/