Some sailors say that zinc-plated chain is the way to go, as opposed to galvanized chain because of the vast difference in price ($1.80 versus $3.00 per foot). Can I use the cheaper priced chain?
Kathy Barron responds:
Chain is made of steel, and steel does not live very long in a saltwater environment unless it is protected. Coating the steel to prevent corrosion is the best way to protect it, and zinc is the metal of choice for such a coating since it is durable and adheres well to steel. Zinc itself corrodes very little and is easily plated on (or plated off by electrolysis).
Zinc plating forms a very thin coating over steel chain. When it is chipped or nicked, the steel underneath is exposed, and rust and deterioration will begin almost immediately in the marine environment. Most plated chain is designed for use in shoreside commercial applications like automotive, logging, or farm projects where corrosion is not as severe a problem as it can be around boats.
Chain for marine applications is hot-dipped galvanized, and this process forms a much thicker coating of zinc that is more durable than plating. It is much more expensive, of course, but I have always found that you get what you pay for. Coating the steel is done to reduce or minimize corrosion and the longer the coating wears, the longer the chain will last. If it starts to rust quickly and needs an expensive replating (if you can even locate a replating company) it may cost more in the long term than buying the better product in the beginning. Good luck with your decision making.