New Sta Lok Showing Rust

[northcaptain]

Hi have installed a new rigging this year with swaged terminal at the top and mechanical Sta Lok at the bottom. The wires has been cut with nuclear grade disks to avoid contamination, cleaned, rounded and i made the choice of not using caulking for better inspection capabilities later. But i didn't expect the Sta Lok to show sign of rust after only 2 months ! ( i have 11 terminators and they are all showing rust)

Evidently, the salted water collects inside the terminator and the capilarity make it goes up a litte into the wire. On the picture the backstay shows more rust on one side than the other, which means there is a pool of water inside and when new water enters in (spray or rain) the surplus falls of the slanted side.

I will have to inspect and re-install at the end of the season but this is definitely a problem, i wonder if others have had that issue and how have they solved it ?

Fair winds,

Andre
S/V Impermanence

[skipmac]

I think your problem is crevice corrosion. Choosing to not use caulking inside the Stalock was not a good idea. Stainless steel sealed in stagnant water will deplete the oxygen and cause corrosion, not prevent it so you created the perfect scenario for creating rust. From the photo it appears the rust is not on the Stalock fitting but coming out of the fitting where the wire has corroded inside.

Depending on how bad the corrosion on the wire you should be able to disassemble the fittings, clean, seal with the recommended caulking and reassemble.

[Sailmonkey]

Your hypothesis is correct. I installed several Stalok fittings and Hayn Himod fittings. The Staloks were sealed with polysulfide sealant and show mild rust staining, the Hayn fittings I left unsealed and all look as bad if not worse than yours.
In my mind the open space allows renewal of the water and introduction of oxygen to keep the stainless healthy.

[skipmac]

By the way, it has been years since my last Stalok installation but I'm pretty sure the written instructions with the fittings say to use a sealant inside the fitting. They would not add that to the instructions without good reason.

[Sailmonkey]

Yes, the stalok instructions say to add the sealant, the himod instructions say to not add the sealant. I think one of the major differences though is the design of the fittings, the stalok is a cup to catch water the himod does not have the water catch feature (although with the lanocote on the threads I cant' see the water draining
through the threads).

[belizesailor]

Yes, per manufacturers instructions (after all -- they did design and build the thing) you want to use sealant. A rigger I know, who has worked a lot with Sta Loks, says he has only ever seen one with bad corrosion issues and it was not sealed.

[barnakiel]

Hey, but it is Sta-lok, is it not?

Open, inspect, improve, re-assemble.

BTW I always assemble with 5200 / Loctite and never any rust.

b.

[skipmac]

Originally Posted by barnakiel

Hey, but it is Sta-lok, is it not?

Open, inspect, improve, re-assemble.

BTW I always assemble with 5200 / Loctite and never any rust.

b.

But if you use 5200 are you able to open and inspect without using dynamite?

[DeepFrz]

From barnakiel

BTW I always assemble with 5200 / Loctite and never any rust.

Why in the world would you use an adhesive to assemble something that should be disassembled and checked periodically?

[barnakiel]

Originally Posted by skipmac

But if you use 5200 are you able to open and inspect without using dynamite?

5200 is not applied on the threads, that's what Loctite is used for. The goo goes inside and as you screw the assembly together it fills the gaps between strands making water penetration if not impossible then at least more difficult (or so I believe).

I opened our 5200 filled Sta-Loks twice and it is a very easy job.

BTW an assembled terminal of any kind can be slightly preheated and then immersed in liquid paraffin. Later just wipe out excess and let it cool down slowly. Some sailors claim this is a better way than using the goo.

b.

[conachair]

Originally Posted by DeepFrz

From barnakiel

Why in the world would you use an adhesive to assemble something that should be disassembled and checked periodically?

I´ve a selection of stalok & norseman, the the adhesive qualities of any sealant are insignificant compared with the mechanical forces going on if dissembling. Still not a nice mess to clean up though. And they recommend replacing the cones if disassembled so it´s quite a major job anyway. Not really yer periodically type of thing.

[skipmac]

Originally Posted by barnakiel

5200 is not applied on the threads, that's what Loctite is used for.

Well yes but I tend to spread goop everywhere when trying to do a job like this. Worried that with my messy technique, if I got any 5200 on the threads I would be getting the torch (I mean a real torch, not a flashlight for you guys from the other side of the pond) out to open the fitting.

Originally Posted by barnakiel

The goo goes inside and as you screw the assembly together it fills the gaps between strands making water penetration if not impossible then at least more difficult (or so I believe).

That was how it was explained to me and seemed to work. Rerigged a Morgan with Staloks in about 1976 and last time I saw it 4 years later the fittings had not a spec of rust weeping from the wire.

[sailr69]

Looks to me you have a problem with the wire not the terminal, they use both 316 and 314 for rigging, most fresh water boats are supplied with 314 which seems sufficent, for salt water, you need 316. are you sure you recieved 316SS when you replaced the stays?

[DeepFrz]

This is what sta loc recommends.

Caulking use boat life lifecaulk, 3m 101 polysulfide or similar

[barnakiel]

Yes, Sta-Lok says polysulfide or similar (hmmmm, what IS similar to polysulfide anyways?) while riggers at Southern Spars (poor ignorants) use any kind of 5200, 290, 291, Lifecaulk or similar laying around.

The comment above on the wire can be very correct - some SS wire seems to weep much more than other. We have some older wires here that are prime (prime to to look at) and some pretty recent ones that are a bucket of rust (unless I wipe them pretty often, which I do).

I never had any trouble opening or replacing StaLok fittings, but I may be a happy go lucky as the biggest wire here is 6 mm only. So I stand corrected that it may well be that bigger terminals are more difficult to open and re-assemble.

The cones are very inexpensive, btw.

Cheers,
b.