Regalvanizing Anchor Chain

[Nicholson58]

Originally Posted by 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

For what its worth, I believe the max temperature in the Armor Galvanize retort is around 900 F. I think this is too low to damage heat treated chain.

[Cheechako]

Originally Posted by 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

Yeah.. how did they do it in the first place? It surprises me that galvanizing temps would change the heat treatment...?