Peening C link chain connector

Bowlerhat

Bowlerhat

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I want to add 10m of chain to my anchor. I am aware that C-links reduce the overall strength by around half, but I don’t intend to test the limits. My aim is a cheap extension and the C-link fits the bill.

However, I have never tried to peen the rivets on one and intend to do the job in situ (i.e. at the marina). Anyone had particular success or failure in this? I’m looking at small anvils and the like, but any other top tips would be gratefully received. Thanks.
 
If the 'C' link you are going to use will reduce the overall strength of your chain by 50% - then you have the wrong 'C' link and you are wasting you time wondering about how to peen the rivets.

Go and buy, or sit at home and do it mail order, and buy a genuine Crosby 'C'. link. I buy my Crosby shackles from Tecni (in the UK) but there must be other outlets. Tecni offer a sensible mail order service (or its good from an Australian perspective) and I don't know anyone else.

Check Vyv Cox' wenbsite and he has chapter and verse on 'C' links. This is the link you need:

C-links

Now if you are using G70 chain then you are right, the connector will not be man enough but as most people use G30 chain I suspect you will not be reducing your rode strength by 50%.

Peening is easy - protecting the pontoons to satisfy the owners of the marina might be more difficult. If you would not peen on your deck why would you imagine you can do it on their pontoon? :).

Describe the surface you will be using, pontoon, concrete - it will help with recommendation on how to do it.

Jonathan
 
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Thank you for the replies. I did search the form for C link before posting, but now I have looked again I have found this:

Crosby C links - peening studs

Plenty of great advice in here. I had already discovered the Crosby links, which I know do not reduce the strength of the chain, but the rivets as a result do seem very difficult to peen.
 
If the rivets were easy to peen the links themselves would not be strong enough. There is a direct relationship between steel hardness and strength.

I'd use Norman's, very, big hammer as my anvil on something large, like a 10mm steel sheet, to protect the surface on which you are working. Norman's small hammer still needs to be quite hefty. To focus the small hammer blow I might use a hefty high tensile bolt, say 10/15mm - obtainable from your local hardware store.

Its not as difficult as you imply.

Do not think that you can heat the 'C' link, say to weld it or make it easier to peen, you will destroy its tensile strength.

Jonathan
 
Neeves said:
Go and buy, or sit at home and do it mail order, and buy a genuine Crosby 'C'. link. I buy my Crosby shackles from Tecni (in the UK) but there must be other outlets. Tecni offer a sensible mail order service (or its good from an Australian perspective) and I don't know anyone else.

Jonathan
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Tecni are easy to deal and the delivery was quick. I used them for some G209A 3/8" shackles and even got a conformity certificate in the post.
 
I think there is a basic misunderstanding about riveting (or peening). It's not about bashing the thing with a great big hammer. Riveting is a fairly gradual process, best achieved with repeated directed blows with a relatively light hammer. I have successfully used a half pound ball pein hammer. Many here will not have experience of riveting with copper nails and rooves with clinker built boats, but it is a similar process. The riveting contributes nothing to the strength of the link, but is required to hold the two halves tightly together.
 
NormanS said:
I think there is a basic misunderstanding about riveting (or peening). It's not about bashing the thing with a great big hammer. Riveting is a fairly gradual process, best achieved with repeated directed blows with a relatively light hammer. I have successfully used a half pound ball pein hammer. Many here will not have experience of riveting with copper nails and rooves with clinker built boats, but it is a similar process. The riveting contributes nothing to the strength of the link, but is required to hold the two halves tightly together.
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I am not saying you are wrong but most riveting is done with soft or very soft rivets. Your copper nails have an initial hardness of around 60 - 100 VPN. Red hot steel rivets in shipbuilding probably less than that. Crosby C-links are, at a guess, 300 VPN or thereabouts, about twice the hardness of the chain they are joining. You could tap away all day with a half pound hammer and not make much impression.
 
vyv_cox said:
I am not saying you are wrong but most riveting is done with soft or very soft rivets. Your copper nails have an initial hardness of around 60 - 100 VPN. Red hot steel rivets in shipbuilding probably less than that. Crosby C-links are, at a guess, 300 VPN or thereabouts, about twice the hardness of the chain they are joining. You could tap away all day with a half pound hammer and not make much impression.
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They are designed to be riveted. ?
 
Yes, a ballpeen hammer. That is what they are for, obviously. But 16-25 ounce. I'm old school and have a bunch of sizes. When I was a kid they tought riveting in school at about 15 years of age. Some paid attention.

A 10- to 12-pound hammer should work for bucking , or anything of similar weight. I would put that on top of a timber.

If you are worried about the pontoon, move the boat to a bulkhead, pull out some chain, and do it on-shore.
 
Thank you all. Some great advice here. The boat will be out of the water. I will have a workmate with a lump hammer secured on the top of it. I will use a heavyish ballpeen hammer to repeatedly round the rivets such that the c-link passes through the windlass. I’ll probably go for the Crosby. Thanks again – I’ll report back.
 
Bowlerhat said:
Thank you all. Some great advice here. The boat will be out of the water. I will have a workmate with a lump hammer secured on the top of it. I will use a heavyish ballpeen hammer to repeatedly round the rivets such that the c-link passes through the windlass. I’ll probably go for the Crosby. Thanks again – I’ll report back.
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I would do it on the ground. I found that my workmate had to much flex when I tried something similar.
 
I use the jaws of large vice, it allows the chain links to sit straight and jaws heavy enough to act as dead weight, the first one was not as pretty but worked, the later ones with practice good. Big hammer and persistence seems to be the key
 
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