welding anchor chain

[lifeofreilly57]

Uhm, before going back to school I was a journeyman millwright, I was also a certified welder for pressure vessels. I would never swear my life and boat on a welded chain. Welding and the heat induced stress points it introduces to an already heat treated piece is just a disaster waiting to happen.
how much is you boat worth? How much does a new chain cost?
How much is your life worth?
Chains cheap, loss of life isn't.
Failures usually occur at the worst times.
I've built many things, including motorcycle frames and hot rod chassis that I welded myself, but those were usually either mild steel or chrome moly tubing, which can be easily welded under controlled conditions, anything heat treated requires a different level of expertise. Anything heat treated usually needs to be welded prior to the heat treating process under controlled conditions then heat treated to produce the desired results and to reduce or eradicate the stresses created by the welding process.

[Simi 60]

Originally Posted by RaymondR

If it shows, the attachment is for a Plastimo link of the type I think we are discussing. Firstly, note the warning on the right hand side.

.

It is not what we were discussing at all.
You said shackles and pins of shackles and that ain't one

Originally Posted by RaymondR
The problem with this solution is that the load rating on the shackles which have pins which will fit through the links is probably much lower than that of the chain.

Tested shackles which exceed chain strength are available and the pins easily go through the link.

https://www.nobles.com.au/en-au/prod...n-bow-shackles

[Simi 60]

Originally Posted by captwylie

You can get a welded chain tested at a reasonable price. We built some tools by welding a small piece of chain to a pair of hooks to be used for picking up heavy flanges to weld on the ends of large diameter pipe. We were not allowed to use this tool unless it had been certified for the weight of the flanges. I took the tools to a weight and scale company that certified scales. They attached the tools to a 8,000lb weight and raised it up and set it back down and certified the tools for 6,400lb, 80% of what they had lifted. I think they charged us $50 to certify the tool's weight capacity.

Wow, sounds so easy.
< Drops 1/2 tonne of chain in dinghy, goes ashore, puts chain in back pocket and off to get the link tested. >

Nah, ain't happening.

[Simi 60]

Originally Posted by lifeofreilly57

Uhm, before going back to school I was a journeyman millwright, I was also a certified welder for pressure vessels. I would never swear my life and boat on a welded chain. Welding and the heat induced stress points it introduces to an already heat treated piece is just a disaster waiting to happen.
how much is you boat worth? How much does a new chain cost?
How much is your life worth?
Chains cheap, loss of life isn't.
Failures usually occur at the worst times.
.

Exactly.

[GrowleyMonster]

Originally Posted by lifeofreilly57

Uhm, before going back to school I was a journeyman millwright, I was also a certified welder for pressure vessels. I would never swear my life and boat on a welded chain. Welding and the heat induced stress points it introduces to an already heat treated piece is just a disaster waiting to happen.
how much is you boat worth? How much does a new chain cost?
How much is your life worth?
Chains cheap, loss of life isn't.
Failures usually occur at the worst times.
I've built many things, including motorcycle frames and hot rod chassis that I welded myself, but those were usually either mild steel or chrome moly tubing, which can be easily welded under controlled conditions, anything heat treated requires a different level of expertise. Anything heat treated usually needs to be welded prior to the heat treating process under controlled conditions then heat treated to produce the desired results and to reduce or eradicate the stresses created by the welding process.

For high test chain you are right, I think. At least mostly right. However the OP specifically mentioned BBB chain. Pretty soft stuff. Stick that together with a 7018 rod and definitely the weld is not the weak part, and definitely there is no heat induced weak spot in the link that is appreciably weaker than the rest of the link, anyway. The only real issue is the galvanizing. Cold galv spray needs to be renewed pretty often, to remain effective as the rest of the chain, I think. It chips off, rubs off, wears off, very very easily. However, you can easily see when the welded link starts to rust, and weld up another one.



I know nothing about the galvanizing rods. I didn't even know that there was such a thing, TBH. Sounds interesting, though.

[Simi 60]

Originally Posted by GrowleyMonster

Stick that together with a 7018 rod and definitely the weld is not the weak part,.

You have no idea.

You assume everyone is a skilled welder with the right machine, stable power in a decent environment.
Reality is somewhat different.

[Jim Cate]

If we are talking about BBB chain, the C-links are as strong as the original chain... at least the ones from Crosby and other similar vendors. It is only when one gets to better than grade 40 chain that the links are weaker than the chain.

Jim

[captwylie]

Originally Posted by Simi 60

Wow, sounds so easy.
< Drops 1/2 tonne of chain in dinghy, goes ashore, puts chain in back pocket and off to get the link tested. >

Nah, ain't happening.

You don't need the whole chain. One link will do. Cut it in half weld it back together. You could take it to a weld testing lab and have them pull it apart. They can tell you exactly at what psi it broke. If you know someone that works at a construction company they can take it to work and pull it for you. We do it all the time on piping projects. It is called qualifying a welding procedure.
The important thing is do what gives you peace of mind. I worked as a welder for 30 years and after that as an AWS certified welding inspector for 18 years. I weld everything together but I have confidence based on my experience. Could I be confident sleeping while on anchor with my welded link? Absolutely. But if it keeps you awake at night worrying about it then buy more chain. The important thing is to do what you feel comfortable with.

[a64pilot]

Originally Posted by Adelie

BBB and ProofCoil are regular 30ksi steel.
HiTest/G40/G43 uses alloying to increase strength or you wouldn’t be able to buy it hot dip galvanized

https://www.cruisingworld.com/how/yo...g-anchor-chain
https://www.morganscloud.com/2011/05...-anchor-chain/

Higher grade chains (70,80,100,120) are heat treated which make hot dip galvanizing problematic. I believe there are some alternative methods that can uses at considerable expense.
http://blog.uscargocontrol.com/diffe...ade-100-chain/

Heat treated or tempered chain can be bought hot dip galvanized as it’s likely a little over tempered during manufacture and slightly annealed during the galvanizing process.
However any additional regalvanizing after manufacture may or likely will further anneal the chain, depending on how long it’s submerged and how hot it got and how it was cooled.
However just as a guess, it’s not likely to be significant on grade 70 chain, just as a guess, I’d guess around 10%, but that is a WAG.

I’ve not seen higher than G70 chain used for anchoring, I have used much higher grades of chain for securing loads on aircraft etc though, but none of it was galvanized, it was all gold cadmium plated I believe.

[GarthGregory]

About 15 years ago a welder in my employ welded insitu the main blade of the rear suspension on a Mercedes Truck tractor ( 25 Ton capacity ), the blade had cracked right through . This was an emergency solution and a very temporary fix . As it is in life ,it was in place for 6 x months before it was replaced and was still perfect when removed . Clearly it was welded with the correct rod ( can't remember ) . Based on that ,I would weld a chain , with the right tradesman and the right rod and then galvanize that section .Rgds Garth

[RaymondR]

I had to pull the anchor this morning so I ran the chain out to collect this image.

The chain on the left is the section which resided in the bottom of the locker and appears to have suffered some areas of slight corrosion of the gal coating. The chain on the right has just been re-galvanized and is now the section which will mostly remain on the locker bottom.

I slightly overbuilt the weld. Of interest is the survival of the gal coating on the welded links.

[Uncle Bob]

Originally Posted by RaymondR

I had to pull the anchor this morning so I ran the chain out to collect this image.

The chain on the left is the section which resided in the bottom of the locker and appears to have suffered some areas of slight corrosion of the gal coating. The chain on the right has just been re-galvanized and is now the section which will mostly remain on the locker bottom.

I slightly overbuilt the weld. Of interest is the survival of the gal coating on the welded links.

Obviously you are an experienced welder and know your boundaries, however there are those out there that believe that a few ferocious sparks and red hot metal is all it takes.
For an experienced skilled welder, yes, for those not so skilled, no.

[Simi 60]

Originally Posted by Uncle Bob

:
For an experienced skilled welder, yes, for those not so skilled, no.

Even to many of us that are trade qualified skilled its not worth it even though I carry a welder, rods, dropsaw etc on board and have a genset and inverter to get the job done.

Smaller lighter boat maybe, but then I would not be carrying the above gear onboard.

I reckon the $1600 odd we paid for new, 1/2 inch tested, Australian made chain with documentation is money well spent.

The sleep at night value is priceless.

[RaymondR]

Originally Posted by Uncle Bob

Obviously you are an experienced welder and know your boundaries, however there are those out there that believe that a few ferocious sparks and red hot metal is all it takes.
For an experienced skilled welder, yes, for those not so skilled, no.

Nope, I'm a 74 year old man with a bad case of the shakes and have to hold the electrode holder with both hands. I have my own welding equipment from when I owned a steel boat but It's not hard to throw an anchor chain in the boot of the car and go find a welding shop.

[JB0101]

Sorry for any redundancy from previous posts and length. When it comes to welding, you will get hundreds of opinions. Most from perception and few from experience. On this subject, we are actually concerned with the owner/crew peace of mind as this will only come to fruition if you experience the worst of conditions. I suspect when it comes to chains the first consideration would be low hydrogen followed by tensile strength. As mentioned earlier, rods and wires come in various tensile strengths (one mentioned 7018 which means 70Klbs/sq"). To ease your mind, contact a local welding school, and ask the instructors if you can bring in a sample to be tested for tensile strength. Schools should have capabilities of testing bending and possibly tensile. Discuss with the instructor what your concerns are and the lengths of chain needed for test equipment. Have your welder cut off that length from the chain and have him/her weld the link. Take it to the school and ask the instructor to conduct the tensile test. My money is on the test resulting in the weld holding and the original material giving way. For years I had always heard that a good weld is stronger than the material, which I could never understand until I saw it first hand. Made me a believer. However, the process must be completed exactly each time. Once the weld proves stronger, have welder conduct same process. If failure of weld, seek new welder. Also, my opinion is that the welded link only needs to exceed the capability or your rode, deck fittings, anchor, shackle, and other weak links. I am of the mind, how much chain do you need to clear the bottom? Prior to clearing the bottom, you have chaffing issues, after that, only strength and elasticity are of concern. Chain prevents chaffing, but rode provides shock absorption.