Thanks for that - bugger about the chainplates. I can't see much uni there. In a Newick tri we built we used the Farrier reinforcing method and had about 9 laminates of 2 plies of uni and 1 of db at 600. It was massive over an HD insert and used 12mm bolts. In my own 38ft cat I have my cap stainless chainplates on the outside leading through a 20mm ply pad with 12mm bolts with uni ribbons laid over and into the bilge with 2 600 db plies over. Now I would just go composite - so set and forget and no water ingress. Stainless chainplates are a pain if they go wrong. Always something to learn on your videos.
Thanks mate. Just in the process of building carbon chainplates here in El Caribe. It's infinitely better than what was there before. We will get to the videos on this process in the next month or so.
Wow, thanks for sharing. I am moving my Catana 48 Swift in a couple of weeks to Rio Dulce Guatemala into dry dock. I will be inspecting the chain plates, needles to say.
My engineering is a little rusty, but my memories of torque and nut retention and Junker vibration testing is this. It's all about the CLAMPING. Shear should never happen. If you are in shear, then clamping has already failed. Bolts hold the plates in clamp friction which holds the load. Shear means it's insufficient tension and friction.
Correct however we are not dealing with a steel on steel situation. We are metal on composite which is a very different beastie. The clamping pressure is very difficult to achieve due to through thickness stiffness of the composite panel. Due to this you cannot achieve decent clamping pressures so we look at this situation as a plate with multiple shear pins in it. Also the steel to epoxy surface means the skin friction is too low unlike the steel on steel scenario.
I'm not an engineer, but what I find misleading about this video and others who produce videos for TH-cam is their knowledge of some engineering, but as one commenter already mentioned, it's the surface friction between the chainplate and the bulkhead which is produced by the tension of the bolts. It then becomes a matter of whether the bolt is sized properly for the desired torque value. Please tell me if I am mistaken. Thanks
It depends on how the chainplates is designed. It can be made so that it relies on clamping friction but this would require many bolts which are generally smaller. The other option is the bolts become dowels in shear. This requires less bolts but they need to be of bigger diameters. The latter option is more suited to composites as composite structures don't like holes in them. There are a lot of issues with composites being clamped when they are a cored structure (as our bulkheads are) because you cannot apply enough clamping force for it to be in friction. This means the bolts will have to be in shear for it to work. This is the reason why we ended up building composite chainplates.
Extremely informative! Thank you again!! I think I can speak for many viewers when I say that we love the deep technical stuff you guys do.
Thanks mate. Glad to hear you are enjoying the content
I gotta say I’ve learned more about bolts in the first 5 mins of this video than I ever knew there was to learn! Super interesting 👍🇦🇺
Brilliant 👍
So helpful and informative, just found your channel--loving it!
Awesome 😎
We've been working on our website with loads of extra stuff too so make sure you check it out www.youngbarnacles.com
I'm in awe! Shayno got mad skills, even if he does talk to camera while running power tools.
Hahaha! I know right?! He's getting better tho.... at least I can get him to talk to the camera now 😉
Great class on the right way . He is a professional.
Thanks for that - bugger about the chainplates. I can't see much uni there. In a Newick tri we built we used the Farrier reinforcing method and had about 9 laminates of 2 plies of uni and 1 of db at 600. It was massive over an HD insert and used 12mm bolts. In my own 38ft cat I have my cap stainless chainplates on the outside leading through a 20mm ply pad with 12mm bolts with uni ribbons laid over and into the bilge with 2 600 db plies over. Now I would just go composite - so set and forget and no water ingress. Stainless chainplates are a pain if they go wrong. Always something to learn on your videos.
Thanks mate. Just in the process of building carbon chainplates here in El Caribe. It's infinitely better than what was there before. We will get to the videos on this process in the next month or so.
Fancy 65ft racing / cruising mono currently hauled beside us had the G10 chainplates fail in the Heineken last year. Wrong laminate profile.
Wow, thanks for sharing. I am moving my Catana 48 Swift in a couple of weeks to Rio Dulce Guatemala into dry dock. I will be inspecting the chain plates, needles to say.
Good idea! Feel free to send any questions to us and we'll help as best we can 👍
Thank you for another amazing video.
You're welcome 😀
Super detailed info.
Glad you liked it
My engineering is a little rusty, but my memories of torque and nut retention and Junker vibration testing is this. It's all about the CLAMPING. Shear should never happen. If you are in shear, then clamping has already failed. Bolts hold the plates in clamp friction which holds the load. Shear means it's insufficient tension and friction.
Correct however we are not dealing with a steel on steel situation. We are metal on composite which is a very different beastie. The clamping pressure is very difficult to achieve due to through thickness stiffness of the composite panel. Due to this you cannot achieve decent clamping pressures so we look at this situation as a plate with multiple shear pins in it. Also the steel to epoxy surface means the skin friction is too low unlike the steel on steel scenario.
I'm not an engineer, but what I find misleading about this video and others who produce videos for TH-cam is their knowledge of some engineering, but as one commenter already mentioned, it's the surface friction between the chainplate and the bulkhead which is produced by the tension of the bolts. It then becomes a matter of whether the bolt is sized properly for the desired torque value. Please tell me if I am mistaken. Thanks
It depends on how the chainplates is designed. It can be made so that it relies on clamping friction but this would require many bolts which are generally smaller. The other option is the bolts become dowels in shear. This requires less bolts but they need to be of bigger diameters. The latter option is more suited to composites as composite structures don't like holes in them. There are a lot of issues with composites being clamped when they are a cored structure (as our bulkheads are) because you cannot apply enough clamping force for it to be in friction. This means the bolts will have to be in shear for it to work. This is the reason why we ended up building composite chainplates.