Sta-lok fittings--is threadlock essential?

[Megunticook]

Just made up some new standing rigging with Sta-lok threaded fittings. I followed the instructions precisely that I got from the Sta-lok website, which are also on the bags that the fittings come in. Then I got to the last fitting, and the bag had a sticker on it saying it was "important" to use a small amount of threadlocker to lubricate the threads upon initial assembly. So I put some blue threadlocker on that one.

The Sta-lok instructions didn't say anything about threadlocker. You think I should go back and redo those ones I assembled dry, or not worry about it?

Didn't notice any difference in threading the fittings between the dry and the threadlock. Both seemed to tighten down the same and felt very secure (cinched down tight but not crazy tight). The Sta-lok instructions specifically said they don't need to be super tight to hold. I tightened them down with a small hand-wrench to where there was good resistance but not so I was "forcing" it to go further. My gut tells me it's fine but thought I'd check with others. Am stepping the mast tomorrow so now would be the time.

Is the risk that these would somehow unthread through vibration? Can't image that happening but I suppose it's possible.

Interestingly I used a Sta-lok last year for the first time, used blue threadlocker based on what someone on this forum recommended, took it apart this year and went to re-use it but the threads were galled--I went to chase the threads and couldn't on the female part--tried using oil, plenty of force, and the threads were just buggered. So had to replace it. Bad luck or did I do something wrong?

[John Stone]

Just made up some new standing rigging with Sta-lok threaded fittings. I followed the instructions precisely that I got from the Sta-lok website, which are also on the bags that the fittings come in. Then I got to the last fitting, and the bag had a sticker on it saying it was "important" to use a small amount of threadlocker to lubricate the threads upon initial assembly. So I put some blue threadlocker on that one.

The Sta-lok instructions didn't say anything about threadlocker. You think I should go back and redo those ones I assembled dry, or not worry about it?

Didn't notice any difference in threading the fittings between the dry and the threadlock. Both seemed to tighten down the same and felt very secure (cinched down tight but not crazy tight). The Sta-lok instructions specifically said they don't need to be super tight to hold. I tightened them down with a small hand-wrench to where there was good resistance but not so I was "forcing" it to go further. My gut tells me it's fine but thought I'd check with others. Am stepping the mast tomorrow so now would be the time.

Is the risk that these would somehow unthread through vibration? Can't image that happening but I suppose it's possible.

Interestingly I used a Sta-lok last year for the first time, used blue threadlocker based on what someone on this forum recommended, took it apart this year and went to re-use it but the threads were galled--I went to chase the threads and couldn't on the female part--tried using oil, plenty of force, and the threads were just buggered. So had to replace it. Bad luck or did I do something wrong?

Jim Walsh and a few others have rerigged their their boats with sta-lok fittings. So I would seek out some input from them. I do seem to recall reading on the old Spar-Talk forum run by Brion Toss that he was adamant that a small dab of 3M 4000 or similar bedding compound be used on the cone end to keep salt water out. I bet you can do a google search on that issue. Hopefully Jim will comment if he is not out sailing.

[Tod Mills]

Do you think galling might be an issue?

[kerrydeare]

Just made up some new standing rigging with Sta-lok threaded fittings ... The Sta-lok instructions didn't say anything about threadlocker ... The Sta-lok instructions specifically said they don't need to be super tight ...

As long as you follow the Sta-Lok guidelines closely and do not deviate, you will not encounter problems. Period.

[John Stone]

Just made up some new standing rigging with Sta-lok threaded fittings ... The Sta-lok instructions didn't say anything about threadlocker ... The Sta-lok instructions specifically said they don't need to be super tight ...

As long as you follow the Sta-Lok guidelines closely and do not deviate, you will not encounter problems. Period.

Generally true...but not always. There is a lot of info out there regarding this issue. You have to do your homework and decide for yourself since you are the one that’s going to be out there on the proverbial dark and stormy night. While I would not follow the advise of the local marina expert I would certainly consider information presented by practical sailor and Ralph Naranjos. Personally I would go with Brion Toss’ recommendation before I blindly followed the manufactures instructions and summarily dismiss his enormous rigging expertise. As always, gather as much info as practicable and make the best decision you can.

Anyway, here is just a sample of the thinking about compression fittings including sta-lok:

https://www.practical-sailor.com/blog/m ... eal-or-not

[Jim Walsh]

I just looked through my records and I replaced all my standing rigging in 2010. I bought all my 1X19 wire and trimmed it to the finished length using a miter box and a hack saw with a 32 TPI blade. I used all Sta-Lok except for the fork fittings (uppers) on my lower shrouds. For those I used Hi-Mod because they had a fork for the proper sized clevis pin.
I slid the socket onto the wire, I fit the wedge onto the core of the wire and ensured the strands were evenly spaced. I put the former into the end fitting and tightened the components then took the end fitting off to ensure the wires were not caught in the wedge but were evenly spaced.
For the final assembly I put a dollup (less than the size of a grape) of Life Caulk polysulfide in the end fitting and some blue Loctite on the threads of the socket. I used the proper sized wrenches to tighten the components, and wiped of any excess polysulfide which squeezed out.
I check that they are still tight every spring but I have never had any which was loose. There has never been any visual indication of rust or any other abnormality which has led me to believe any of the fittings should be disassembled for further inspection.

[kerrydeare]

Just made up some new standing rigging with Sta-lok threaded fittings ... The Sta-lok instructions didn't say anything about threadlocker ... The Sta-lok instructions specifically said they don't need to be super tight ...

As long as you follow the Sta-Lok guidelines closely and do not deviate, you will not encounter problems. Period.

Generally true...but not always. There is a lot of info out there regarding this issue. You have to do your homework and decide for yourself since you are the one that’s going to be out there on the proverbial dark and stormy night...

Seems to me that the manufacturer (in particular Sta-Lok) should be the first, rather than the second or third, choice when it comes to obtaining information on their very technical products. Especially if one is planning for any dark and stormy nights.

[John Stone]

Kerrydeare:

When given the choice, I put my trust in the hands of skilled competent operators long before I put it in the hands of designers and engineers. Ask the families of the aircrews and passengers of Lion Air Flight 610 how they feel about the reliability of MCAS designed by Boeing engineers and installed in the 737 Max.

As I said, we each have to decide where to place our trust. There are no guarantees. Do your homework and choose wisely.