Corroding galvanized shackle - anchor

[Ralph Johnstone]

Crosby 3/8" G-209A Alloy Screw Pin Anchor Shackle - 2 Ton WLL - #1017450

It is an interesting observation by @Ralph Johnstone but I don't think that's the problem.

Yipes. Even a more interesting observation on your part @dLj . It's not hot galvanized, it's not electroplated galvanizing, it's .............................

So let's all forget the SS vs. carbon steel brouhaha and bull-.

@skunther , you've already got one of the best of the best shackles in hand so why not haul out your Dremel and power wire brush the whole thing and then paint with your favourite corrosion inhibitor, many times over.

I still maintain that the shackle would be better off if it wasn't in contact with the SS side wall. But furthermore, why is Crosby using paint on a steel alloy product rather than hot galvanizing as everyone else does today.

 

[dLj]

Yipes. Even a more interesting observation on your part @dLj . It's not hot galvanized, it's not electroplated galvanizing, it's .............................

View attachment 214902

So forget all the SS vs. carbon steel brouhaha and bull-.

@skunther , you've already got one of the best of the best shackles in hand so why not haul out your Dremel and power wire brush the whole thing and then paint with your favourite corrosion inhibitor, many times over.

I still maintain that the shackle would be better off if it wasn't in contact with the SS side wall. But furthermore, why is Crosby using paint on a steel alloy product rather than hot galvanizing as everyone else does today.

Interesting - when I went looking for that shackle, I saw a couple places saying it was hot dipped galvanized. The photo of the part told me that could not be the case. Painted? Lordy, that's lame for a marine shackle...

It also makes sense given the rapid corrosion being experienced by @skunther with those shackle...

As to your point of getting a shackle that is actually hot dipped galvanized - I'd like to know who is making them. I don't know of anyone still doing it in shackles. But I'd sure love to know if there is someone still doing it.

dj

 

[Ralph Johnstone]

I'd like to know who is making them. I don't know of anyone still doing it in shackles. But I'd sure love to know if there is someone still doing it.

The reason I thought hot galvanizing was still the norm on all ferrous products but without any real proof, is that when I wander through out local supply shop, Martin Marine, it seems like every time I come across anything that is steel or cast iron ie. cleats, anchors, chain and its fittings, they're rough as hell and covered with an inch of dust. I'll take a look next time I'm in there which is just about every day during the winter.

 

[twalker H260]

Crosby does still make hot dipped shackles. From their website they indicate shackles 3/8” and smaller are mechanically galvanized rather than hot dipped.

Can a 7/16 shackle pin fit through your chain links? This would give you the hot dipped version.

Crosby® 209A Alloy Screw Pin Anchor Shackles | Crosby®

Crosby's full catalog and product listing of the Crosby 209A Alloy Screw Pin Anchor Shackles.

www.thecrosbygroup.com

 

[Ralph Johnstone]

Crosby does still make hot dipped shackles. From their website they indicate shackles 3/8” and smaller are mechanically galvanized rather than hot dipped.

Cheap beyond f***ing words.

Some bean counter at Crosby figured out a way to screw the customer for a few dollars more and some one in charge said "Yah. Let's screw 'em !" Send in an order for several hundred shackles and I'm quite sure they could get them hot dipped for well under $5.00 ea. No one with any thinking capacity is going to buy a Bargain Brand Crosby Shackle for $5.00 less than a regular hot dipped Crosby shackle if it means "Painted Only. Sorry, No Hot Zinc. Sorry, No Returns. Sorry, No Refunds."

 

[dLj]

Crosby does still make hot dipped shackles. From their website they indicate shackles 3/8” and smaller are mechanically galvanized rather than hot dipped.

Can a 7/16 shackle pin fit through your chain links? This would give you the hot dipped version.

Crosby® 209A Alloy Screw Pin Anchor Shackles | Crosby®

Crosby's full catalog and product listing of the Crosby 209A Alloy Screw Pin Anchor Shackles.

www.thecrosbygroup.com

That's good to know. I'm not surprised the smaller shackles are mechanically galvanized. It's quite difficult to maintain dimensional stability on smaller parts, on the larger parts they are more forgiving. So moving to mechanical galvanizing is really an over-all better solution. The problem for the marine environment, and especially on ground tackle, it simply cannot perform as well as hot-dipped galvanized parts. I posted some time ago on here the details of why, along with a microstructural image.

dj

p.s. Just found it: H 41 CHAIN REPLACEMENT

 

[skunther]

So these were advertised on Westech Rigging’s website as hot dipped (actually I see the next Iine after “hot dipped” states: Sizes 3/8" and below are mechanically galvanized), which didn’t clue me in to the fact that they are just painted. “Mechanically galvanized” was a pretty nebulous term to me.
Anyways, does anyone know if and where there are any 3/8” hot dipped shackles (that are actually hot dipped) out there?

 

[jviss]

So these were advertised on Westech Rigging’s website as hot dipped (actually I see the next Iine after “hot dipped” states: Sizes 3/8" and below are mechanically galvanized), which didn’t clue me in to the fact that they are just painted. “Mechanically galvanized” was a pretty nebulous term to me.
Anyways, does anyone know if and where there are any 3/8” hot dipped shackles (that are actually hot dipped) out there?

I googled it. Here's one:
CM 3/8" Screw Pin Anchor Shackle (WLL 1 ton) (Hot Dip Galvanized)

 

[jviss]

And Amazon:
MarineNow 3/8" US Type Drop Forged Galvanized Bow Shackle with Over Size Screw Pin for Anchor, Towing, Off Road Recovery (3/8" with 7/16" Pin 1 T WLL) Hot Dipped Galvanized

 

[Hello Below]

Anyways, does anyone know if and where there are any 3/8” hot dipped shackles (that are actually hot dipped) out there?

The maker of Rocna anchors, Canadian Metal (Pacific), also world class marine anchor chain, anchor rodes, lines, and shackles for every kind of boat.
High Strength, Forged, Hot Dipped Galvanized Shackles
Fisheries Supply
And of course
Amazon.com

 

[dLj]

I googled it. Here's one:
CM 3/8" Screw Pin Anchor Shackle (WLL 1 ton) (Hot Dip Galvanized)

Difficulty is the pin is not appear hot dipped... I would not be happy with that in this application.

dj

 

[dLj]

And Amazon:
MarineNow 3/8" US Type Drop Forged Galvanized Bow Shackle with Over Size Screw Pin for Anchor, Towing, Off Road Recovery (3/8" with 7/16" Pin 1 T WLL) Hot Dipped Galvanized

That sure looks like a great find! And certainly cheap enough - heck you can buy a ten pack for less than a six pack of beer...

dj

 

[skunther]

The maker of Rocna anchors, Canadian Metal (Pacific), also world class marine anchor chain, anchor rodes, lines, and shackles for every kind of boat.
High Strength, Forged, Hot Dipped Galvanized Shackles
Fisheries Supply
And of course
Amazon.com

Yup, easy enough to google that. Thanks!

 

[jssailem]

when I wander through out local supply shop, Martin Marine, it seems like every time I come across anything that is steel or cast iron ie. cleats, anchors, chain and its fittings, they're rough as hell and covered with an inch of dust.

I would suggest, that Martin Marine knows what their clientele are expecting and only procures what they feel they can sell.
crosby-shackles
Crosby marketing says the shackles come in "Galvanized" and "Self Colored" finishes.

For <$20 I’d rather just have a shackle that doesn’t corrode than to mess with cleaning and painting it every year.

Said by every sailor who ever got on a boat. Unfortunately Mother Nature never rests.

All these systems have pros/cons. Our boats are a compromise. Some tasks like maintenance and inspection are just done because we want to come home safely.

I do find the discussion of the various materials interesting. It helps me consider the options of spending money to get an item that may require less maintenance, yet if I want to come home safely, I am not relieved of inspection and corrective action should the materials fail to live up to their hype.

 

[jssailem]

Those
High Strength, Forged, Hot Dipped Galvanized Shackles
Have a "Bold black colored pin". Is that marketing speak for "Painted Pin"?
From an engineering perspective, I can understand the idea of the colored pin. They can get a much better pin thread manufactured. It maximizes the size of their thread in the shackle reducing the potential for pin failure. They can get better results during their load failure testing. I note that none of their testing is done after 2 years exposure to marine environment use. After a boat owner has dipped into the deep, dragged it back forth and over rocks, coral, and exposed the shackle to the potential of stray current corrosion from a fleet of boaters.

 

[Hello Below]

Have a "Bold black colored pin". Is that marketing speak for "Painted Pin"?

John (Ooooops, edited), the pin is definitely painted. In CMP's case, I believe that the paint differentiates between load limits of their 2 - 3/8" shackles, one 4,000lbs (black coloured pin) and the other 2,200lbs (copper coloured pin). According to the link: Forged, Hot Dip Galvanized coating on both the shackle and pin.

 

[skunther]

So that's a bit confusing too. I was about to pick up the Titan, but was concerned the pin might not be hot dipped. I checked their website, which states the pin is hot dipped. Then saw @jssailem and @Hello Below's posts. Is painting and hot dipping an either/or scenario? Is it hot dipped as advertised, and then painted? Or is the pin just painted?

 

[Hello Below]

Is painting and hot dipping an either/or scenario?

No. It is an AND function. Hot dipped AND painted, copper coloured (it used to be yellow) identifying normal strength or black coloured identifying high strength.

Is it hot dipped as advertised, and then painted?

Yes

Or is the pin just painted?

No

 

[jssailem]

@skunther The good news it is your boat and you get to do what ever you desire to do.

If it was my anchor and chain, I would remove the shackle. Inspect it. Wire brush the offending rust. Examine the metal. If the rust has not invaded the metal structure (surface rust), I'd give it a coat of cold galvanizing paint and put it back on the chain. I would monitor the shackle for the season and see what develops. If it looks questionable I'd remove it and get a new shackle.

If I wanted to test my powers of observation, I'd take it to a shop like WesTech Rigging and ask them to do a load test on the shackle. Store Locations This test will give me a certified report of the load strength.
They are conveniently located in my town and for a few bucks they will pull the shackle apart and give me the load results. This test will give me a certified report of the load strength. Good info on a partially used shackle to let me know how it compares to a new shackle. I can then decide where and what I can buy to replace the shackle.

You could search for a nearby site that can provide proof load testing services. You might look to the port and ask one the marine service shops how they assure the cables they make meet the load test requirements. Their may be a rigging shop like WesTech Rigging up there. Certainly the Logging industry uses such a service from a rigging company.

Most of these things on a boat have a safety plus factor designed into them.

 

[skunther]

This today from Crosby:

“Apparently the problem I am being told on this is the metal of the Shackle is Alloy & the metal of the anchor is carbon which is probably causing this issue.”

I just ordered 5 of the hot dipped 3/8” Titans that @Hello Below recommended. Hopefully that addresses it. Worst case if they still corrode, I can replace them yearly for $7 a pop.