Why is my new rigging going rusty?

[PhillM]

This year I have had all the standing rigging replaced. Just 4 months later there are signs of rust where the wire enters the STA Lock terminal. This is affecting the forestay, and four out of five shroud stays. But one lower and the backstay seem OK.

I am assured that the wire is “proper” 316 Stainless borght from a reputable marine supplier. The terminals are STA LOCK and they too seem reputable. The rigger is reputable and so will not be named here. He is going to take a look tomorrow, no arguments – he was as surprised as me when I told him what I had seen.

I wondered if the panel had any experiences or opinions that might help track down the problem. Obvious is the quality of the wire and that will be checked, but anything else I should be thinking about?

 

[DickB]

I had a very similar situation with my new standing rigging 18 months ago. I was disappointed that rust appeared very quickly just above the terminals but I cleaned it off with SS cleaner and after a couple of cleans it seems to have stopped reappearing. I don't know why but maybe the surface has microscopic particles that rust up initially but when polished smooth they all go away. Anyway, the result is now fine with little or no rust appearing. cheers,

 

[vyv_cox]

The usual cause is corrosion occurring in tiny crevices in the wire surface. The crevices are barely visible, caused by variable lubrication in the dies when the wire is formed. It is not harmful, just looks poor, and is usually solved by polishing, using an abrasive polish or possibly by very fine wet and dry, 1000 grit or more.

 

[tudorsailor]

Buy some Spotless Stainless. No effort required. Gets rid of the superficial rust marks. Admire the shine

TudorSailor

 

[silver-fox]

I had a very similar situation with my new standing rigging 18 months ago. I was disappointed that rust appeared very quickly just above the terminals but I cleaned it off with SS cleaner and after a couple of cleans it seems to have stopped reappearing. I don't know why but maybe the surface has microscopic particles that rust up initially but when polished smooth they all go away. Anyway, the result is now fine with little or no rust appearing. cheers,

Exactly my experience.

 

[PhillM]

Thanks all, SS cleaner it is then. Delighted to hear its not a serious problem

 

[PhillM]

Went down to the boat last night for a look with the rigger. It looks like the rust is INSIDE the STA LOK terminals. The only one that is not showing rust is one that I bought towards the end of last year, so it was not replaced as part of the re-rig.

The rigger thinks it might be the cone inside that is rusting. He is going to get a replacement terminal so he can swap one out and take a closer look.

Has anyone had any problems with STA Lok / cones?

 

[vyv_cox]

I always put sealant inside mine to prevent ingress of water. Fittings at the lower end of shrouds are the ideal place for crevice corrosion, and probably galvanic corrosion in the case of Norseman and Stalok fittings.

 

[PhillM]

I always put sealant inside mine to prevent ingress of water. Fittings at the lower end of shrouds are the ideal place for crevice corrosion, and probably galvanic corrosion in the case of Norseman and Stalok fittings.

Thanks Vyv, which sealant do you use?

 

[vyv_cox]

Thanks Vyv, which sealant do you use?

Most I have done have been Sikaflex, which I usually have open. I believe I have seen silicone mentioned, would be less messy. Some of the new hybrids seem to be very good, just about to try some. Almost anything that won't dissolve in water should be OK.

 

[mjcoon]

Most I have done have been Sikaflex, which I usually have open. I believe I have seen silicone mentioned, would be less messy. Some of the new hybrids seem to be very good, just about to try some. Almost anything that won't dissolve in water should be OK.

But does it not have to bond well with the SS, else water will seep in but no oxygen?

Mike.

 

[lustyd]

He is going to get a replacement terminal so he can swap one out

By which I hope you mean he's going to replace a wire. They are designed to be easy to fit but not to be removed and replaced and the wire will likely be damaged by removal.