Norsemans even badly done!

[Robbie.g]

Just checked over a boat today.... tayana 42....norseman fittings both ends (eye to stud on 10mm) of the D1's. Fitted by the owner in the Marquesas, cone in the correct place, but only tightened enough so 5 threads were buried, then 'sealed ' in with silicone. On the check saw there was way too much thread showing, so removed them.. unscrewed them by hand (easily), found that the wire had'nt even formed around the cone, and the like that had done the trip around the pacific islands and on to nz!!
Just goes to show that the reforming of the wire around the cone is the 'belt n braces', as all the load is held in the taper... Quite interesting.... That said i find many 'correctly' assembled norsemans arrive at the shop, undo with only hand pressure, (no loctite.. obviously!).

Oh the reason the D1's got replaced was because the top bolt of the Selden Seltang they were attached, failed... muntered the tang and the stay. (Professionally intalled apparently! New ones fitted)..Equally interesting!!

Any thoughts/similar experiences?

[Brion Toss]

Hello,
I've seen things like this before, once on a boat that had come through a hurricane. And note that, on Hayn fittings, which have the highest break test numbers of any of this type of terminal, the ends are never bent over. Having said that, what you found was not a good thing, but just a bad thing that didn't break. Given a good factor of safety in the wire size (and for all I know it might have been very high), the maximum possible sustained load on the wires might have been no more than 40% of the rated wire strength. And it is unlikely that the actual sailing loads that the rig saw were less than 20% of the wire's strength. Even if we were to discover that the terminal as you found it would pull out at 60% of break, it doesn't look like a problem.
But we have safety factors for good reason. What if the boat were to experience a shock load, or a series of shock loads that exceeded the design max? Unlike Hayn's, Norseman's are designed to be maximally efficient with the wire bent over. I don't know how much of a difference it makes to either strength or security, but I'm not about to assume it is an optional step.
As a separate point, not engaging all the threads is just another, completely different way to weaken the terminal, so we might ask how close to the edge this boat has been sailing, given the combined deficiencies you saw.
As for the absence of Loctite, there are seldom forces that act to unscrew terminals significantly; the point is that there sometimes are, so we glue those threads down.
Fair leads,
Brion Toss

[knothead]

Originally Posted by Robbie.g

.....then 'sealed ' in with silicone.

Any thoughts/similar experiences?

I can't remember how many times I've taken apart a mechanical fitting and been amazed that it hadn't failed. Like all rigging, thankfully, they seem to be very forgiving.
Unfortunately, the sea isn't .
That is one of the problems that I have with the perpetuation of the belief that mechanical fittings are superior to swages. Too many unqualified installers.
While a StaLoc or Norseman isn't really difficult to install, as many of us know, it's easy to screw them up. Unless a person has had a little training or watched a video or something, they don't know what to look for.

Speaking of silicone, what do you recommend for caulking the fittings?

[Robbie.g]

thanks chaps for the replies.
Silicone is not ideal as a sealant on mechanical fittings as many brands emit acetic acid on curing (they smell vinegary). This apparently is not that good on the stainless.
I belive stayloc stipulate 3M's 101, and norseman is 'polysulfide' caulk.
Regards

[knothead]

Originally Posted by Robbie.g

thanks chaps for the replies.
Silicone is not ideal as a sealant on mechanical fittings as many brands emit acetic acid on curing (they smell vinegary). This apparently is not that good on the stainless.
I belive stayloc stipulate 3M's 101, and norseman is 'polysulfide' caulk.
Regards

I've read the same thing about the acid in silicone. Do you have any idea if that continues to be an issue even after the material has cured?

Another question/thought I'd like to run by you, (not to hijack the thread) is about using sealants, caulks etc. in swages.
When I first started in business years ago, I had a habit of melting beeswax into the wire above the swage fittings and letting it seal the top.
Later, I began the practice of using different products on the wire before swaging. Such as locktite or 5200.
What are your thoughts about that?

[Robbie.g]

We generally swage 'dry' unless the wire was cut using a angle grinder, then we dip the cut end in lanacote, just on the off chance that the heat generated in the cutting has affected the "stainlessness" of the wire. Any how when pull tested there was no reduction in the strength when compared to a 'dry' swage. Don't know about any more complex caulks etc, as lanacote is only mineral + fish + wool oil mixed!
I think on just about any boating site there are people who have strong veiws in all directions.
My 2 cents is : Dry is the go, we should reallywork under the instructions of the people that make the swagers we use; and as far as i know that means 'dry'.
Cheers

[Brian Duff]

use the search on this website, just above and to the right a bit, and enter - swaging questions - check out the 3 page posting there.

We fill 'em up.