Neeves
Well-Known Member
A member here complained when his anchor chain needed to be regalvanised after 4 years. I recall, maybe incorrectly, he did not follow this route, re-galvanising, as his chain was a G70 and he feared that re-galvanising would reduce its strength. The short life of the chain was a bone of contention and the manufacture enjoyed a bit of stick. The member also suggested smaller chain would suffer a shorter gal life, my tests in which I compared 6mm, 8mm 10mm and 12mm - finds this is absolutely rubbish. The main criteria is galvanising thickness and the quality of the galvanising (and Vyv has a neat test to evaluate galvanising quality ( a link twist test). With thickness of galvanising - you are on your own (I use a coating thickness meter - the sort that might be used for engineering paint work thickness, or by galvanisers). Most engineering products, steel beams or reinforcing rode is galvanised to a 70 micron coating thickness (includes the raw zinc). This is also the specification used for galvanisers for chain (as there are no other specifications). Engineering units suffer no abrasion and if you have your chain regalvanised its would be worth identifying if the processor could offer you a thicker coating (as it will last longer - up to a point).
I've conducted some chain abrasion tests simply hanging short lengths of chains on a a beam of galvanised rod under our cat, beam to beam, so that the chains are abraded by the silica sand seabed and measuring weight loss resulting from the movement of our cat, wind and tide, on a swing mooring. I had a number of investigations - how long did the gal last, which gal was better and did chain size impact wear
I was amazed and appalled that I could remove all the gal off chain in 4 weeks. My test was thus accelerated - as obviously anchor chains last much longer than 4 weeks of continued usage.
Another member here documented the usage of his yacht and the life of his galvanising and I took the data he provided - and the answer came out the same - 4 years life.
I only mention any of this as there is a thread on CF and 2 members there are talking of 3-4 years life. Having anyone make a stab at galvanising life is not common - and I do watch out for comment.
Italian Maggi vs Chinese-made Lofrans chain - Page 2 - Cruisers & Sailing Forums
Check post 27.
Now 4 people reporting on galvanising life is hardly statistically sound - but its a better data point than nothing
For most people 3 - 4 years life, or, say 1,200 nights at anchor, is longer than they will own the yacht - but for liveaboards it might be an interesting data point - to schedule into your maintenance regime.
Of G70 chain - regalvanising - go for it - I've tested it - there is no loss of strength if you regalvanise conventionally coated, Hot Dipped Galvanising , G70 chain. Don't take my word for it, America's biggest chain maker told me the same thing. Just tell the galvaniser its a G70 chain and grit blast rather than pickle. Instead of grit blasting - drag the chain behind your car across a dry beach, or along a quiet road (and end for end it). But get it to the galvaniser the same day - raw steel rusts overnight (and will not take the gal).
If you use your chain as a live aboard you might not notice the gal has gone, though if you look you will see it. But your chain will wear more quickly than the galvanising (as the galvanising is harder than the chain) - so if you leave re-galvansing you are eating into your chain. Regalvanise sooner rather than later.
Jonathan
I've conducted some chain abrasion tests simply hanging short lengths of chains on a a beam of galvanised rod under our cat, beam to beam, so that the chains are abraded by the silica sand seabed and measuring weight loss resulting from the movement of our cat, wind and tide, on a swing mooring. I had a number of investigations - how long did the gal last, which gal was better and did chain size impact wear
I was amazed and appalled that I could remove all the gal off chain in 4 weeks. My test was thus accelerated - as obviously anchor chains last much longer than 4 weeks of continued usage.
Another member here documented the usage of his yacht and the life of his galvanising and I took the data he provided - and the answer came out the same - 4 years life.
I only mention any of this as there is a thread on CF and 2 members there are talking of 3-4 years life. Having anyone make a stab at galvanising life is not common - and I do watch out for comment.
Italian Maggi vs Chinese-made Lofrans chain - Page 2 - Cruisers & Sailing Forums
Check post 27.
Now 4 people reporting on galvanising life is hardly statistically sound - but its a better data point than nothing
For most people 3 - 4 years life, or, say 1,200 nights at anchor, is longer than they will own the yacht - but for liveaboards it might be an interesting data point - to schedule into your maintenance regime.
Of G70 chain - regalvanising - go for it - I've tested it - there is no loss of strength if you regalvanise conventionally coated, Hot Dipped Galvanising , G70 chain. Don't take my word for it, America's biggest chain maker told me the same thing. Just tell the galvaniser its a G70 chain and grit blast rather than pickle. Instead of grit blasting - drag the chain behind your car across a dry beach, or along a quiet road (and end for end it). But get it to the galvaniser the same day - raw steel rusts overnight (and will not take the gal).
If you use your chain as a live aboard you might not notice the gal has gone, though if you look you will see it. But your chain will wear more quickly than the galvanising (as the galvanising is harder than the chain) - so if you leave re-galvansing you are eating into your chain. Regalvanise sooner rather than later.
Jonathan
