Pecco 10 Posted March 23 Share Posted March 23 Pls I need some help. Cavalier 32 50 years old encapsulated (glassed over) chain plates. Pls see the pics They reslly need to be replaced.... I really would not want to reglass them in. I am thinking of taking the old one off the hull. Re glass the void. Reproduce the same chain plate (with a knee and horizontal plates and going for the same deck exit location). Make a new matching plate to through bolt from the outside of the hull. Intuitively I 'd think I would need to through bolt in all the locations where the original chain plate were glassed in right (vertical and horizontal)? This way I would be spreading the load to the hull the same way the designer intended to. Following this route would put some holes pretty low and close to the water line..maybe even under the water line. I need to measure properly. it makes me a bit doubtful and I am wandering if I can avoid bolting the lowest horizontal ones. Any suggestion would be very appreciated. Cheers! Quote Link to post Share on other sites
Black Panther 1,589 Posted March 23 Share Posted March 23 What is your objection to reproducing the original, they are well proven. In fact why are you wanting to replace them? 1 Quote Link to post Share on other sites
Pecco 10 Posted March 23 Author Share Posted March 23 It is definitely proven to work over time. The concern I have with the design is that you can not inspect it and the environment you are creating for the chain plate is far from ideal...replacing in the future is hard. I finally got the time and courage to take off all the lining that always obstructed a proper inspection. The reason for wanting to change them is because there is evidence of water ingress from the deck. Bit of rust here and there, where the chain plate is exposed, no idea what s happening behind the fiber glass. Where the chain plate enters the hull, the glass is actually funneling inwads. Rather then making water go away it would have actually facilitated its ingress.... lastly 50 years is a long time and it feels like a bet I wouldn't want to take. So, I may be overdoing it but, it would be a peace of mind kind of thing... I ve just redone the keel / hull joint seel because of some water ingress in the joint. Not fun but it needed to be tuckled properly, detach, inspect, re seal....again peace of mind, good for another 50 years. I guess I could reglass them in but, I am not too keen on the amount of grinding and dust, that is another factor.....lots of factors....mainly my inexperience and ignorance Quote Link to post Share on other sites
Black Panther 1,589 Posted March 23 Share Posted March 23 Ok, might need a professional opinion to know for sure, but the rust you see could be from 50 yrs of condensation. They weep a lot, if anyone knows a solution to that one I'd love to hear it. Sounds like a nasty job , good luck. Quote Link to post Share on other sites
K4309 260 Posted March 23 Share Posted March 23 Sounds like there is more risk, or as much risk, in a redesign than there is keeping them as is. What is the background, are you planning a voyage in the Southern Ocean, or Gulf Cruising? Brand new rigging can fail. Sure, there is a correlation with very old rigging failing, but that doesn't exclude new gear failing. Especially if it is a novel or un-proven design. Or poorly installed. An alternative design is to glass in a large lump of hardwood. You could then screw the chainplates straight to that, keeping them visible, so you meet your objective for inspection etc. This is what we have on our 40 yr old boat, but it is a wooden boat in the first place, so the large lump of hardwood is already integral to the boat. Putting bolt holes through the hull sounds like a recipe for all sorts of issues. Point loading on the hull skin itself would be the obvious one. A point for cyclic loading is another, and the one you have already identified is water ingress. That, and if you have a failure with through bolts, you have an immediate risk of sinking. Where as if your chain plates fail as is, you have a risk of the mast coming down. While a substantial inconvenience, loosing the mast is normally a perfectly manageable situation. 2 Quote Link to post Share on other sites
Pecco 10 Posted March 23 Author Share Posted March 23 Yes, tedious job for sure but, you I've got to do what you ve got to do to do what you want to do. I can hear how it sounds like over doing it but, I ll be going offshore so I feel that I need to asses/address all the structural element of the boat. K4309, thank you for pointing out how the bolts could actually cause troubles, good points! I need to be confident that with hard work, humbleness and knowledge the maintainens I do on the boat is emproving it, I could not own an old boat otherwise. I am wandering if an xray or eco sounding could help...? Ultimately using the same design could actually work. Inspection would fall back into the priority list given that I d be monitoring water ingress... Part of the doubts are that I don't know what happened in the decades prior to my ownership.. As you said BP, I definitely need a pro looking at it....my daughter's magic wand is out of order Quote Link to post Share on other sites
Jon 360 Posted March 24 Share Posted March 24 As an inspector I’d suggest you get a boatbuilder to do a little exploration, remove some of the glass and see if the corrosion is surface or crevice ? This will dictate your next action, document / photo this process as this will help with insurance and certification etc going forward. Plus an insurance company and safety inspector will accept a qualified boatbuilders recommendation ‘If they need to come out and be rebuilt your still then able to do either all or some of this work but follow the professional advice 1 Quote Link to post Share on other sites
Black Panther 1,589 Posted March 24 Share Posted March 24 Hull is balsa cored so what youmight end up drilling through that Quote Link to post Share on other sites
Black Panther 1,589 Posted March 24 Share Posted March 24 What Jon said Quote Link to post Share on other sites
Pecco 10 Posted March 24 Author Share Posted March 24 Sure I am all in for the pro advise! I ll let you know how this evolves. It may take some time before i can get someone to have a look though.... 100% work vs 0% lately......looking to stay the same for a while.... Quote Link to post Share on other sites
harrytom 643 Posted March 24 Share Posted March 24 Build new brackets and put back in same place.Start drilling new holes lower down recipe for disaster. You will find where existing is bolted that section of hull will be strengthened to take load.Start drilling lower down and I think you are opening up a can of worms,What made you think they needed replacing? Quote Link to post Share on other sites
K4309 260 Posted March 24 Share Posted March 24 6 hours ago, Pecco said: Yes, tedious job for sure but, you I've got to do what you ve got to do to do what you want to do. I can hear how it sounds like over doing it but, I ll be going offshore so I feel that I need to asses/address all the structural element of the boat. K4309, thank you for pointing out how the bolts could actually cause troubles, good points! I need to be confident that with hard work, humbleness and knowledge the maintainens I do on the boat is emproving it, I could not own an old boat otherwise. I am wandering if an xray or eco sounding could help...? Ultimately using the same design could actually work. Inspection would fall back into the priority list given that I d be monitoring water ingress... Part of the doubts are that I don't know what happened in the decades prior to my ownership.. As you said BP, I definitely need a pro looking at it....my daughter's magic wand is out of order Boat surveyors can do ultrasound. I don't know if that is applicable for looking for corrosion in steel that is embedded in glass. They normally do solids things like steel hulls and what not. I think it primarily reports thickness. In saying that, ultrasound can work out if I cracked a rib (my rib, not the boat's), so it may be able to identify inconsistent thickness associated with corrosion. Oh, and it may be cheaper to pull them out, inspect and replace. But, to find it is just a phone call to find out. Just google marine surveyor. I spoke to a handful recently on another matter. They will say if they can do it or not over the phone. If it is a legit inspection option then you can consider it, if not, you can rule out some sort of in-situ inspection. If you do replace them, I think there is a lot of logic in copying the existing design. For example, if the hull is balsa core, then it is possible / likely the area around the chainplates is solid layup (ultrasound would tell that), but balsa elsewhere. Or just things like load paths and what not. The basic logic is that design has been robust for 50 years, if the issue is age causing corrosion, the issue is age, not the design. You could come up with a new design, but you need to verify that it is appropriate somehow, esp for CAT 1 inspection and survey. Nothing verifies a design as appropriate as 50 years of use, and on a high numbers production boat. Quote Link to post Share on other sites
Pecco 10 Posted March 24 Author Share Posted March 24 In my heart I new the answer to the peoblem....just redo what is there I suppose I needed a confirmation that hell grinding and vacuum blowing was the solution. It may end up not being to bad ...the whole process of dismantling the cabinetry, insulate the working space for dust, rebuilding everything, is actually more involving than the job it self. I tell myself that this is probably the last big job left.... 1 Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.