How tight for Sta-Loks?

[Jim Glenn]

Greetings! I'm changing rod rigging to 316 stainless, 5/16" & 3/8"
1X19 cable with Sta-Lok end fittings. Nowhere can I find recommended
torque values for how tight the Sta-Loks are to be. I've had
recommendations from "Until there is resistance" all the way to
"Whatever you can apply with one arm." The limiting factors has been
described as either damage to the Sta-Lok threads or crushing the cable
strands.
Any recommendations or experience on the subject?
Thanks in advance,
Jim

[Armond Perretta]

>Jim Glenn wrote: ... recommended torque values for how tight the Sta-Loks
are to be ...

Best bet is to talk to a professional rigger with experience in Sta-Lok
fitted rigs. In the meantime, here's what Sta-Lok has to say about the
subject (Step 7). Not too quantitative.

Good luck and good sailing.

s/v Kerry Deare of Barnegat (remove "BOAT")

http://www.geocities.com/colosseum/sideline/8620

"In theory, there is no difference between
theory and practice. In practice, there is."

***

FITTING INSTRUCTIONS (copied from the Sta-Lok data sheet)

STA-LOK terminals should be used with PRE-FORMED single strand (1 x 19}
7-strand (7 x 7 and 7 x 19) & DYFORM wire ropes. It is not suitable for any
other construction. The 1 x 19 WEDGE (which is normally enclosed in the
marine pack) is plain, but the 7-strand WEDGE has a castellated ring with
six gates to take the strands. These different WEDGES are NOT
interchangeable and the correct one for 'single' or 'seven-strand'
construction MUST be used accordingly. 7-strand WEDGES are available to
marine pack buyers.

1. The cable to be terminated must be cut cleanly and should be free of
protruding wires of different lengths.

2. Slip the SOCKET part over the end of the cable.

3. Un-lay the outer wires or strands in order to expose centre core to about
the length of the wedge (fig. 1).

4. Slip WEDGE over the centre core of the cable (narrow end first) to a
point where the core and the outer wires protrude about 2mm (3/32~) beyond
the wide end of WEDGE (fig. 2.).

5. Re-lay the outer wires or strands around the WEDGE taking care to retain
the WEDGE in its correct position. During this operation the SOCKET should
be pulled carefully into position over the WEDGE in order to prevent the
wires or strands from un-laying (fig. 2).

6. Check the assembly to ensure that the outer wires are evenly spaced
around the top of the WEDGE and ensure that none of

the wires have slipped into the slot in the WEDGE (fig. 2). Each of the
six outer strands of 7-strand ropes should lie in the 'gates' provided (not
illustrated).

7. Insert FORMER into the threaded hole in the END FITTING and screw the END
FITTING on to the already assembled unit and finally tighten with a spanner
(fig. 3). The force required should be no more than can be applied by one
hand firmly, but without undue force which might damage the thread (fig. 4).
The assembly operation is now complete.

8. For interior water proofing, unscrew the two parts and insert a blob of
caulking (silicone rubber) about the size of a small grape on to the FORMER
inside the bottom of the END FITTING. Apply 2 or 3 drops of Loctite 241
(blue) on to the male thread of the SOCKET. Screw both parts together again
and tighten. Both caulking and thread locking are recommended.

RE-ASSEMBLY

The END FITTING may be unscrewed whenever required for inspection or
re-wiring. When re-wiring cut the end of the cable containing the WEDGE and
discard this part including the WEDGE. Always use a new WEDGE when
re-wiring. The remainder of the terminal parts may be re-used a number of
times if they have not been damaged in service.

STA-LOK is a registered trade name. British Patent No. 1441929. World-wide
patents have been applied for.

MADE IN STAINLESS STEEL 316 THROUGHOUT.

[macnaughton.com]

If you don't have a good feel for this sort of thing I would get a torque
value from Sta-Lok. However to amplify on their own instructions: You should
use ordinary open end wrenchs of exactly the right size. I would not
recommend using large adjustables. This way you will probably not have
enough leverage to damage the threads as long as you don't force them past
the point where they are firm. Never add to the length of your wrench to get
more leverage.

Tom MacNaughton
http://www.macnaughtongroup.com

Armond Perretta wrote in message <6q21cm$35h$1...@camel25.mindspring.com>...

[Tony Gill]

Hi Jim,

Someone else has posted the STA LOCK instructions and all I
can say is follow them. Use the right size spanners (wrenches?) and
get them as tight as you can just by holding them.

I rigged Alystra (a heavy 38 ft ketch) in 1979, using STA LOCKs
throughout. She has sailed over 40,000 miles commercially, as a
charter and cruising school boat, in northern waters in all
weathers, has been laid up afloat on a mooring in a Scottish Loch
every winter, and has never had a rigging problem. The STA LOCKs
are as good as new.

It is important to follow the instructions to the letter,
especially the bit about re laying the wire properly, and cutting
the ends to the same length.

I found the best way to do this was to bind the wire tightly with
plastic insulation tape at the cutting point, cut the wire close
to the tape (I used bolt cutters) and then with one of those small
four inch angle grinders, I ground the end so that all the strands
were flush.

As suggested I used silicone sealant to keep the water out, which
it has done completely.

I will use them again if they are still available when I need them.

I have no connection with STA LOCK. After I purchased all mine, I
met Anya at the boatyard where we were both building our own boats.
She was brought up in East Anglia, England, and it turned out that
her father knew the chap who developed and manufactured these
terminals. I wish I'd met her earlier.

Cheers Tony Aux ketch Alystra

[Jim Glenn]

Thanks to all who have replied so far & to those who will later reply.
I called the Sta-Lok factory rep & the reply he gave me was that
there was no stated torque value for the fittings. He said that the
greatest danger was to damage the threads by being over tight & the
fitting would not be re-useable. He said "It should be as tight as you
can get it with one arm. Not quite as tight as two people hauling on a
halyard." It would be great if the factory had a recommended torque
value or how much to tighten down after resistance is felt or how many
threads should still be visible.
I haven't found Loctite 242 (blue) but have Loctite 241 (blue). I
suspect that is a typo. The West Marine riggers recommended using 3M
5200 sealant instead of silicone.
Thanks,
Jim

[adriaan snyman]

Jim,

Sounds like you got real good advice. The nut grade - blue stuff is what
you want (i.e. not shaft grade etc. - you would never get it separated to
re-use) I agree with the use of 3M5200.

Adriaan

[Harrison Evatt]

If you ever need to take apart the fitting, won't 5200 make it much more
difficult.
harrison

[Anders Svensson]

5200 (or similar compounds) have only a fraction of the winding-binding
power that blue LocTite has. The idea is to put a good sized blob of this
so that rain and spray cannot enter. If you completely fill the unevitable
voids between wire, cone and fitting this may work, but it is equally
possible that the goo also keeps moisture in, wich may cause oxygen
starvation corrosion on stainless.

Anders

Harrison Evatt <ev...@ibm.net> skrev i inlägg
<35C7613F...@ibm.net>...