Norseman corrosion

[conachair]

I recently replaced all the standing rigging with dyform, keeping the original norseman fittings but replacing the wedges. A delivery error meant the wedges came from 2 different sources, first ones now look like this

but second batch look like this. Doesn't show up great on photo but there's a little rust seeping from the fitting.

Any pointers as to what might be going on? Doesn't look right . Looks like maybe galvanic corrosion but I thought norseman were only available in stainless.
Thanks in advance

[Brion Toss]

If that is indeed corrosion,it is entirely possible that someone ran a batch with the wrong type of metal; it wouldn't be the first time it has happened. Of course, it is also possible that there is something else in there that is corroding, but it is hard to imagine what...
In any event, your mandatory next step is to disassemble the fitting and taking a good look at the wedge. If it isn't stainless, it should be obvious by now.
Fair leads,
Brion Toss

[davidsamuelson]

Hi,
Brion mentions something else inside. I have seen similar results in fittings; we put it down to the instrument used for cuting the wire - did you use the same cutting tool? Did you really clean it all before assembly? Just a thought. David

[conachair]

Originally Posted by davidsamuelson

Hi,
Brion mentions something else inside. I have seen similar results in fittings; we put it down to the instrument used for cuting the wire - did you use the same cutting tool? Did you really clean it all before assembly? Just a thought. David

Good point, from memory the process for the batch that look OK and the ones that don't was identical, wire cut with 1mm cutting disc in a grinder, cleaned up a little with a file.

Took one apart today. Haven't got a magnet to check that cone is stainless - is there a way to confirm? No further to figuring out what's going on but doesn't look right.






This second batch of cones came from Barcelona via a rigging shop in Gran Canaria so no real way of talking to suppliers. 1st batch (the ones that loook OK) came from UK.

[Douglas]

Hi Conachair,
I have never liked rust - corrosion on my boat's ss, especially since when I attended a West Marine store rigging talk, by Brion Toss. Brion reccommended to everyone, to get a handheld 50 x microscope from Edmund Scientific, and look at your ss using that.

I did and was especially surprised, at getting a good look at the granular ss surfaces, and seeing surface pitting under the rust staining.

I read everything that I could get on the subject of rust on ss, but just recently someone suggested reading the ss guide on this website :

http://www.outokumpu.com/application..._113142858.pdf

What this ss guide does not tell you is that proper design of ss used in a salt water environment, needs to shed off not collect or puddle salt water.

Looks to me that there was not enough squeeze out of your assembly goop from inside the fitting, when it was screwed together.

What ever, you are certainly right to have concern about the rust, left alone, it will get worse and worse.

In your first photo, didn't I also notice a shade of rust between the lay of the dyform wire, too ?


Douglas

[Robbie.g]

I'm no expert, but it looks to me that the cone is stainless as there is no signs of corrosion on or under it, and the wire ends are clean (not the reason for the staining). But where there is some staining is on top of the sealant on the outside of the fitting, the part exposed to the elements. It seems that the sealant has done it's job inside the fitting, although the inner strands near the top of the fitting, do appear to have some staining?![no goo] My feeling is that the staining is tracking down the wire from above, as opposed to beginning at the fitting and travelling up! I would agree that contamination is the cause, but the origin i feel is from the outside/aloft.
i thought that Stainless Steel, was that ...stainless,[not stainfree] and staining differs from corrosion especially that of the crevis variety.?? i'm very happy to be corrected on this definition
There's me 2 cents.