Anchor chain galvanizing


Bill Kinney
 

The last time we had old and tired chain I looked around for a place that could galvanize at a reasonable price.  For what ever reason, I could not find anybody, so we bought new chain.  

We did get an excellent price on that chain, but as we learned later, it was electrogalvanized, not hot dipped.  Electrogalvanizing leaves a VERY thin, although smooth and pretty, layer of zinc on the surface of the chain.  it is generally NOT recommended for applications in "severely corrosive" applications. Soaking carbon steel in salt water certainly has to rate as a "severely corrosive" application.

Now, a bit less than 3 years later, our chain has lost much of its protective zinc layer and is starting to rust.  This time I did manage to find a place reasonably local to where we are who quoted about $300 for 300 feet of chain and our anchor.  This was Baltimore Galvanizing. Since we were in Annapolis at the time, this was a reasonable distance to manage.  The price was attractive since the best price we could find for 300 feet of 3/8 inch (10 mm) G4 grade chain was about $1500 delivered.

We disassembled our Mantus 105 lb anchor, and loaded the three pieces along with the chain on a scrap pallet we scrounged up from the engine dealer at the boat yard. We were fortunate that a visiting friend showed up with a pickup truck to help with the delivery to the plant.  A week later, the work was completed.

For the anchor, we just ordered new, galvanized structural bolts to replace the originals. The originals from Mantus were standard Grade 5 galvanized bolts.  The structural bolts we used were also hot dip galvanized, and the A325 grade has identical strength rating as the Grade 5 originals.  The difference is that the structural bolts have an unthreaded shoulder which makes them stronger in shear loading.

The chain itself was, as expected, significantly rougher in texture than before.  The zinc coating was thick, and well adhered.  There were about a dozen places in the length where a few links had stuck together, but a wack with a hammer fixed these easily as we loaded the chain onto the boat.  The rougher texture meant that the chain does not "flow" as easily as it did before, and piles up in a steeper cone in the chain locker.  No where near high enough to be an issue in the Super Maramu chain locker, but on an Amel54 it might be a problem.

The coating on the anchor was also thicker and rougher than the factory original.  Not as pretty, but hopefully longer lasting!  Our anchor really wasn't in desperate need of new galvanizing, but since we were paying the shop minimum job price, it was included at no additional cost.

Even with the cost of renting a pickup truck to move the chain one way, we spent less than 1/3 the cost of what new chain would have been.

Bill Kinney
SM160, Harmonie
Annapolis, MD, USA


Matt Salatino
 

That’s a great price! We paid twice as much in Guatemala.
we found, after using the chain a few times, it worked better and better through the Gypsies, and in stacking.