Regalvanizing Anchor Chain

[colemj]

Originally Posted by chouliha

ping gmac if memory serves me he is the guru on anchor chain and re galvanizing. Our 3/8 BBB is 30 years old and has been regalvanized 5 times. We currently have in excess of 3000++ nights on anchor.

WOW! That may take the record for cruiser frugality!

I agree about pinging GMac. He doesn't post much anymore, but you can't find another person on earth who knows more about chains, anchors and beer.

Oops, I didn't mean to include that last item…

Mark

[Valmika]

Hi Gjordon,

Who did you find in SFO are to re-galvanize and did you do it yet. I am thinking along these lines also. I read some not too pretty reviews on the new ACCO BBB chain.

Thanks,

Mark

[Group9]

Originally Posted by a64pilot

I believe from what I have read that the only chain that loses some of it's strength is G70, the steel in G40/43 and G70 is the same, just the G70 has been heat treated and re-galvanizing will reduce the strength of G70 by about 10% the first time it'd done and no reduction in strength for further re-galvanizing.
Other forms of chain do not lose strength from being re-galvanized, or at least that is what I have read anyway, I'm no metallurgist.

That's what I had always heard, too (but, I'm no metallurgist, either). That G40/43 will not lose strength if heated correctly during the galvanizing process, where G70 is going to lose some strength, even when heated correctly.

[evm1024]

Originally Posted by Group9

That's what I had always heard, too (but, I'm no metallurgist, either). That G40/43 will not lose strength if heated correctly during the galvanizing process, where G70 is going to lose some strength, even when heated correctly.

G70 will lose about 10% of its strength at the initial galvanizing but will not lose any further strength at the second galvanizing (provided that the galvanizing temps are the same).

Both G70 and G43 are made from 1022 type steel. The difference being that G70 is quenched and tempered (heat treated). When quenched the steel is very strong and brittle then it is heated to the tempering temperature and soaked and cooled at some rate. Galvanizing is much like tempering. The steel is heated to the temp of the molten zinc and then cooled. The temp, soak time and rate of cooling form a complex relationship that changes the structure (and thus the strength) of the steel.

If you were to over heat G70 you would in effect remove all of its heat treating and thus turn it into plain 1022 steel (G43).

To quote from the Peerless (ACCO) catalog:

"Hop Dip Galvanizing exposes chain to elevated temperatures which result in reduced working load limits for heat treated chains. Grade 70 chain working load limit is reduced by 10%, grade 80 chain is reduced by 20% and grade 100 chain is reduced by 30%. All users must be notified of this reduction in working load limits"

So if you re-galvanize G70 try to do so at a place that has good control of the zinc bath.

Regards

[Jim Cate]

Seems to me that re-galvanizing is simply doing over what was done at the factory when they applied the original zinc. With the G-70, they may use a different cooling schedule in order to retain their heat treating benefits, but for the other chains it is likely exactly the same treatment. Thus, worries about the process seem unjustified.

We've had a number of re-galvos over the years, and the quality of the jobs have varied quite a lot, both in thickness of retained coating and smoothness of the coating. If it is lumpy (as it has been a couple of t imes) it sticks in the gypsy and jams the windlass until it finally wears down the bumps... a BIG PITA.

It seems that a lot of galvanizerias have been shutting down of late, likely due to environmental issues. They can be pretty horrible in OSHA terms, too... I remember one in Oakland CA years ago that was right out of Dickens! A really scary place to visit when delivering and collecting our chain! Anyway, it is getting harder to find ones that do chain, so posting addresses or links here on CF would be useful.

Cheers,

Jim

[Snowpetrel]

It will be interesting to see if zinc diffusion coatings such as armour galv start to take over from traditional hot dip galv. PWB here sells marine chain with armour galv coating. I just got some for the same price as the traditional chain. It's supposed to be better. Hopefully it is. I'll know in ten years.. http://www.chainsropesandanchors.co....morGalv%2010mm

Seems like this process would be perfect for g70 chain.

Three of us went thirds on a barrel to get a reasonable price.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

[hpeer]

I've got some chain sitting at an ar or Galv place right now. They are struggling with how to clean it up. Starting to get a bit concerned as it's been on about a month they have had it.

[Nicholson58]

I don't think there is a problem for most chain, maybe only highly heat treated chain.

We used this ArmorGalv | Michigan Metal Coating - Home Armor galvinized. This is used by the military for many of their items and also for many fasteners. In fact, our chain went into the same batch as many drums of identical BBB 7/16 for aircraft tie-downs.

I think this is the same.

https://www.youtube.com/watch?v=zXpcSH4Lj1Q

[GordMay]

Greetings and welcome aboard the CF, Valmika (Mark).

[chouliha]

I for one would be very interested in the Armor Galvanizing mentioned about. 3-4 years should prove its worth. We have the same chain for the past 30 years 3/8 BBB. At that time of purchase higher strength chain was quite a bit more costly. We have had it galvanized I think if memory serves me 4-5 times. The last was in northern Mexico and yes Jim it was like a scary movie. The office was right next to the acid bath and the fumes were pretty intense. Can't imagine what those guys lungs look like after just a month or two.

BTW we have spent about 3000+ days anchored on this chain.

As far as cleaning it. We would spend a couple days with the chain out on the dock with a wire brush on a drill and a hammer trying to clean up as much as possible. But the very best thing I heard of was by our friends on Just A Minute who loaded their chain into the back of their SUV and drove out into the desert. Stopped hooked the chain to the trailer ball and dragged it around for 15 minutes. Stopped end for end and do the same thing. When they loaded it back into the car not a speck of rust just shiny chain! There chain came back from the galvanizes looking new!



Sent from my iPad using Cruisers Sailing Forum

[Jim Cate]

Originally Posted by Snowpetrel

It will be interesting to see if zinc diffusion coatings such as armour galv start to take over from traditional hot dip galv. PWB here sells marine chain with armour galv coating. I just got some for the same price as the traditional chain. It's supposed to be better. Hopefully it is. I'll know in ten years.. 10mm PWB Grade L Short Link Anchor Chain with ArmorGalv | Chains Ropes and Anchors

Seems like this process would be perfect for g70 chain.

Three of us went thirds on a barrel to get a reasonable price.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

Sheesh, Ben, I wish I'd known about your plans! I'll be very interested in your experience with this chain... so get your bum in gear and go do some anchoring! BTW, what kind of price were you able to negotiate?

Oh... do you know if there is a "re-galv" like process for this stuff when the new wears off?

Jim

[Snowpetrel]

Originally Posted by Jim Cate

Sheesh, Ben, I wish I'd known about your plans! I'll be very interested in your experience with this chain... so get your bum in gear and go do some anchoring! BTW, what kind of price were you able to negotiate?

Oh... do you know if there is a "re-galv" like process for this stuff when the new wears off?

Jim

I wouldn't get to excited yet. I noticed that PWB have gone awfully quite on the Armorgalv. Never a good thing... And have pulled all references to it off their site. So maybe we might not have got anything better than the normal hot dipped stuff, or maybe not even as good. Time will tell.

Wayne fromAmbler has some and he is doing some good testing in fiordland at the moment, so we will see.

The catch for us here was shipping. It was very expensive to Tassie, but by getting a whole drum of about 210 meters we got a decent price for three of us.

Seems harder and harder to find decent hot dip galvanised chain these days, I wonder what's being done differently?

[Nicholson58]

Originally Posted by chouliha

I for one would be very interested in the Armor Galvanizing mentioned about. 3-4 years should prove its worth. We have the same chain for the past 30 years 3/8 BBB. At that time of purchase higher strength chain was quite a bit more costly. We have had it galvanized I think if memory serves me 4-5 times. The last was in northern Mexico and yes Jim it was like a scary movie. The office was right next to the acid bath and the fumes were pretty intense. Can't imagine what those guys lungs look like after just a month or two.

BTW we have spent about 3000+ days anchored on this chain.

As far as cleaning it. We would spend a couple days with the chain out on the dock with a wire brush on a drill and a hammer trying to clean up as much as possible. But the very best thing I heard of was by our friends on Just A Minute who loaded their chain into the back of their SUV and drove out into the desert. Stopped hooked the chain to the trailer ball and dragged it around for 15 minutes. Stopped end for end and do the same thing. When they loaded it back into the car not a speck of rust just shiny chain! There chain came back from the galvanizes looking new! Sent from my iPad using Cruisers Sailing Forum

We are several years into this Armor Galvanize on our 320 feet of 7/16 BBB. It is only in the Great Lakes - no salt.

For any re-plating, you will need the chain stripped to white metal. You will only achieve this by blasting.

I found a service in Muskegon, Michigan with a vertical down-blast machine for stripping the old chain to white metal. It is a tower with an impeller to hurl media onto the target below. The impact zone is a moving perforated conveyor belt with a drooping sag built in. The chain is placed in the sag and is made to tumble slowly as the media blasts the rust and old plating away. 70 dollars for 320 feet of 7/16 BBB chain blasted to white metal.

BTW - its harder to find re-galvanizers because the process is really toxic and dangerous. Many platers can no longer comply with regulations.

[gjordan]

VALMIKA, the place I found was in Oakland Calif. I didnt have the work done. Deal fell thru on the boat. I just checked their web site and cant find the prices, but I remember it as very reasonable. PACIFIC GALVANIZING, 510-261-7331. It is probably the same place that Jim Cate mentioned as being a little scary. It has been there for 40 years. Give them a call and get the whole story. Good Luck. _____Grant.

[Adelie]

My research into the topic indicates that regalvanizing BBB & HT(aka gr40 or gr43) any number of times will not affect chain strength. In the case of HT it retains it's higher strength from adding more alloying metals to the steel.

Higher strength chains such as Grades 70, 80, and up are heat treated which means that processes such as re-galvanizing that significantly heat the metal will affect the heat treatment and decrease the strength of the metal.


Adelie