Index

SJ23 Standing Rig Maintenance & Replace Wire.

INDEX -  Chain Plates, Stem Plate, Backstay Plate, Shroud Chain Plates, Turnbuckles, Clevis Pin, Rig Failures,
Shroud Covers & Turnbuckle Boots, Mast Foot, Mast Hinge plate, Spreaders, Mast Head, Mast Kerf.

Stainless steel basically doesn't corrode when exposed to fresh water but that doesn't mean you can ignore it.  It just happens at a much slower rate.  Stainless steel must be exposed to air to retain its protective coating.  On salt water stainless steel corrodes faster the further south the boat is.  The general consensus is that in the southern US the rigging must be replaced every 10 years and in the northern US it can sometimes be extended to 20 years.  Maybe a tad longer in Canada but that depends on the weather.  Panache's rigging failed equivalent to the "extended 20 year" time frame.  Talk to knowledgeable people in your area to get local advice on this.

For those of you who leave the mast standing year round a thorough inspection involves a climb to the mast head.  While it is possible to use binoculars to inspect hardware on a motionless mast, this is not a replacement for a thorough close up inspection that usually requires a magnifying glass.  The advantage of leaving your mast standing is that it is generally protected from physical damage but then it's also prone to neglect.  For those of you who lower the mast for winter lay up, this is the best time to inspect the rigging.  There is a stumblebum risk of damaging the turnbuckles when the mast is lying on the deck but judicious placement of your feet can prevent that problem.
 

SPECS - SS, 1" wide, 1/4" thick, protrudes 2" above deck, 3/8" hole, top of hole is 1/4" from top of flange.   TOP
 

SPECS - SS, 1" wide, 1/4" thick, protrudes 2" above deck, 1/4" hole, top of hole is 1/4" from top of flange.   TOP
 

SPECS - SS, 2" wide, 1/4" thick, protrudes 1 7/8" above deck, two 3/8" holes for turnbuckles, top of hole is 1/4" from top of chain plate.   TOP
 

ISSUE 1 - The diameter of the clevis pin should match the diameter of the chain plate hole for full rated strength.  This is NOT the case on the SJ23 where the factory chose to use a 1/4" pin through a 3/8" chain plate hole.  This missmatch creates point loading on the pin which greatly reduces the effective strength of the pin.  You can restore this with a snug fitting SS sleeve slipped over the pin to create a machine fit in the chain plate hole.  Ultimately a pin that matches the hole size is simpler and strongest.

ISSUE 2 - While the upper and lower shrouds appear to have the same 1/4" factory turnbuckles, the toggles are slightly different.  The upper shroud turnbuckle has a 3/8" T-bolt and toggle with thicker metal for the stronger forces of keeping the mast standing.  The lower shroud has a 1/4" T-bolt and thinner metal for keeping the mast in column.  Check yours to confirm they are in the correct position.  This is a subtle thing that is easily overlooked.  While you are at it, position the pin with the locking ring pointing aft so you can see the ring from the cockpit. 
 

Upper shroud (factory turnbuckle) Notice the 3/8" diameter T-bolt.  It is stronger but limited to 1600 pivot angle.

Lower shroud (factory turnbuckle) Notice the 1/4" diameter T-bolt.  It is can pivot to 2000.

ISSUE 3 - When the mast is down the upper shroud turnbuckles cannot lay flat on the deck and you risk bending or breaking the T-bolts if you step on them while they are attached to the chain plates.  To solve this, secure the shrouds to the grab rails so the turnbuckles are suspended in the air.  As such they are still a tripping hazard but at least you can see them better and reduce the chance of breakage.  This is due to the limited 160⁰ pivot angle of the T-bolt in the toggle.  You could solve this by filing the inside corners of the toggle to increase the pivot angle to 200⁰.  You only have to remove a little bit of metal from both sharp corners to protect the T-bolt.  See Deck Storage.  TOP
 

A friend was sailing his SJ28 downwind in heavy air when he noticed the boom lowering ever so gently into the cockpit.  Thinking that the mainsail halyard had let go he walked to the front of the cockpit to pull it in.  He didn't know it but the clevis pin on the forestay had let go while he was sailing downwind.  In reality the mast was loose and it was only the wind pressure pushing the sails forward that kept it standing.  Despite all efforts the mast fell.  In the post analysis of the trouble we are pretty sure the clevis pin slipped (downhill) till the LIGHT gauge split ring was against the turnbuckle clevis.  When the pull from the mast was great enough, the strain on the clevis pin became unbalanced ever so slightly, forcing the loose clevis pin to slip down hill with a split ring in tow.  The light gauge elongated ring didn't offer enough resistance to prevent the pin from slipping through the turnbuckle.  A clevis pin diameter that is not matched to the hole in the chain plate can cause the hole to deform or bend/crack the pin.  The diameter of the pin MUST match the diameter of the hole or there will be concentration of stress where the side of the pin touches the hole.  A pin that is smaller than the hole will eventually tilt and strain the split ring. *  This explanation, or a judicious whip of the forestay, flipped the pin off.  Either way, when sailing down wind the forestay is loaded and unloaded with the hobby horsing forces, which are exaggerated since the back stay adjuster was released.  This is when an unloaded pin can slide, aided with gravity and vibration.  While the damage to the end of the pin suggests the split ring was pulled through the turnbuckle hole, the ring might have partially backed off the pin.  We are not actually sure which it was.  It is very difficult to believe but the evidence suggested it was pulled through.  (The damaged pin is shown next to a dime). 
- By the way, the mast came down so gently that it only slightly bent the pushpit.  It never damaged the mast or sails and was standing again two days later.  Luckily nobody was hurt and everybody on board has a story to tell. 

* NOTE - To test the sliding pin theory described above I installed Panache's forestay pin pointed uphill.  It took only 15 minutes for the pin to slide down at the dock after stepping the mast.  The only movement the boat experienced was vibration from the wind.  Notice how the pin is stopped by the split ring.  Needless to say I reversed the pin (pointed downhill) after this test.  Its too bad the hole in the stem fitting isn't sideways to prevent this. *  
- One of the strongest ways to lock a clevis pin is to use the correct gauge cotter pin (diameter must match hole) with an exact fitting flat washer behind it.  Bend the ends of the cotter pin (needle nose pliers) back to itself and tape over it.  The thickness of the washer keeps the body of the pin fully into the turnbuckle holes thereby balancing the load on the center of the pin instead of one end.  If a ring is rotated till both strands are in the pin hole and then taped, the pin will be there to stay.  As a precaution all pins should be pointed aft to the cockpit so you can see the cotter pin or split ring at a glance.  If you tape over them, all you need to know is that the tape is still there! 
- Failing that, all pins should be pointed downhill so gravity keeps it in place. 
- Having followed all these guidelines I later noticed that the pin had slid uphill till the ring stopped it.  This after only a few weeks at the mooring.  Now this really surprised me, especially since it took all my strength to pound it back downhill.  There are many world cruisers who will not risk their life and boat on pins and rings, replacing them with bolts and nylock nuts as is the practice on aircraft.  I have followed suit on Panache`s forestay and drilled a ring hole through the end of the bolt to prevent the nut from spinning off. 

Click here for images of clevis pins.  TOP
 

SWAGE CREVICE CORROSION - Of all the terminals fittings found on a sailboat the deck level swage terminal is the most common source of failure.  This is due to salt water intrusion and to a lesser degree fresh water intrusion.  The water runs down the 1x19 wire and wicks inside the swage.  The damage of freeze expansion can take a few years to set in.  An example of the dreaded crevice corrosion is shown at right, #1.

SWAGE MICRO CRACK - The rest of the swage terminal should be inspected for micro cracks using a magnifying lens.  An example of advanced crevice corrosion is shown at right, #2.

1x19 WIRE NICKS & SCRATCHES - Nicks and scratches that cross multiple strands or one strand deeply are also a possible concern and a candidate for replacement.  So are flat spots.

BROKEN STRANDS - A strand that stands proud, particularly where it enters a swage terminal, is highly suspect.  That is the case shown here on Panache's original factory lower shroud (2020).  While the rigging is 45 years old, the boat was used only 6 months of the year and stored dry under a tarp for the other 6 months.  Panache has only seen fresh water but this failure is within her expected use rate.  So time for replacement.  At the very least, shrouds should be replaced in pairs.  Best to replace all four.

A local SJ24 suffered a broken mast in 2020 which prompted several of us to speculate the reason for the failure.  I was shocked to also discover a broken strand (lower shroud) on Panache as I inspected the rigging only 3 months previous.  This broken strand is not a show stopper for the remainder of this season but out of an abundance of caution I taped over the break to keep the remaining strands in place.  Then I reinforced the shroud with 1/8" Dyneema looped through the top and bottom toggles and tensioned with a trucker's rolling hitch to close the loop.  The Dyneema could actually slacken the shroud.  Needless to say, Panache's shrouds were replaced in the Spring of 2021. 

By the way, the SJ24 mast broke when a 1/4" turnbuckle toggle on a lower shroud broke while sailing close hauled.  When the lower shroud let go, the mast immediately buckled, breaking at the spreaders.  This mast has the optional racing foot equipped turning blocks for internal halyards and a hinge for stepping the mast.  The deck hinge plate was strong enough to stay attached but tore the mast foot and some aluminum off the bottom of the mast.  While the failure was due to crevice corrosion as shown in fig 2 above (rigging was 43 years old), stress fatigue while stepping the mast (Got to loosen the rigging of a SJ when stepping the mast) or stepping on the turnbuckle while it lays on the deck are also suspect.  Expect similar breakage on an SJ23, so look after your rigging.  A replacement mast is difficult to find and expensive to transport.  A used SJ24 mast was found, new shrouds attached and the SJ24 is sailing again.

Hutchamia - Notice the multiple broken strands and advanced corrosion in this SJ23 shroud.  It is corroded about half way through.  I think the previous owner tried to maintain some strength by wrapping the strands with steel wire and then taping over the "repair'" to cover the "meat hooks".  Problem is, the tape sealed the SS in a pocket of anaerobic water, thereby blocking any drying air.  In time that started the crevice corrosion.  Its doubtful it was ever inspected again!  Not to worry, all the standing rigging on this SJ23 is being replaced in 2021 by Jon Raymond, the new owner.

WIRE KINK & STRESS FATIGUE - A sharp kink in the wire also deserves attention and possible replacement.  While stainless steel is malleable, seldom can you straighten 1x19 wire from a sharp kink.  However, I have straightened a 6" radius bend with no problem but it is your call concerning the condition of the wire on your boat.  If you think it looks bad, chances are it probably is and you should replace it.  When a kinked or bent wire is repeatedly stretched and released with each tack it will eventually break.  Generally one strand first, after which the rest let go, domino style.  This phenomenon is called stress fatigue and is exactly the same as flexing a small steel plate back and forth to break it.  This is precisely why the tangs must be in line with the wire.  If you sail the boat with loose rigging over lumpy water, the vibration will hasten this problem.  All this fatigue just takes longer on a boat, BUT the final event happens real quick and comes with a much bigger surprise!    Kaboom......

TURNBUCKLE WINTER STORAGE ON DECK - Once the mast is down resist the temptation to lay the shrouds on the deck.  If you step on a turnbuckle that is attached to a chain plate, you risk bending the T-bolt toggle.  The safer technique is to direct the shrouds up to the cabin grab rails and secure them, thereby leaving the turnbuckles safely suspended in the air.  Less risk of stepping on them.
- The toggle on some turnbuckles can pivot fore/aft 200⁰ ensuring that the T-bolt does not touch the toggle when it lays on the deck.  However, if the turnbuckle can pivot only 160⁰ then the T-bolt touches the toggle when it lays down.  After many cycles this will nick the T-bolt from where a break can start.  I have such a nick on one of Panache's 45 year old turnbuckles.  Hence one of the reasons for the next section!

Turnbuckle boots are less of a problem since more air flows through them due to bigger air space.  But I removed them from Panache at the same time so I can see the lock nuts and rings.  If you still want a turnbuckle boot, get a good one that is sealed to the wire at the top so it can shed rain off the turnbuckle. 

The occasional dousing of rain is good as it cleans the wire.  But beyond that, keeping both dry is akin to preventing corrosion.  TOP  
 

Secure fasteners are critical when you step the mast using the tabernacle.  If the foot should break free of the mast while it is half way up or down, then you will effectively fire the biggest crossbow you have ever seen!  When the mast slides forward, it will do extensive damage to the deck and likely the tow vehicle hitched to the trailer.  If you happen to be in its path, you will require surgery!  Think about it!  TOP

 TOP

The factory spreaders are made of heavy gauge 1" OD aluminum tubing that slip over the two aluminum stubs.  Below you can see the small sheet metal screw that secures the base of the spreader to the top of its stub.  The screws on Panache are 1/2" long and bottom out in the stub.  They must be removed to release the spreaders after the mast is down.  "I set the screws back into each stub for road travel to be ready for next Spring.  While I've never lost one I also keep spares in a 35MM film canister." 

The compression rod and stub assembly also secures the lower shroud tangs.  Each tang MUST be bent in line with it's shroud.  If it is out of alignment, it will eventually break in the same fashion as described above in stranded wire.

Note the different attachment of an early version tang (left) that is pop riveted and glued with sealant to the mast above the stub versus a later tang (right) that is slipped loosely over the compression rod.

For secure road travel I tie the spreaders to each other on deck.  Many sailors use a vinyl spreader caps over the ends to protect the sail cloth.  "Panache's spreader caps are pretty weather beaten as they should be white but the vinyl is in good condition.  They will do for another year till they get too brittle."

EARLY VERSION SJ23 SPREADERS - At the outboard end of these spreaders is an aluminum casting with a split end to secure the cap shroud.  The upper shroud goes through the split and is held captive with a small screw that closes off the split.  This is required to keep a leeward shroud attached while sailing or to keep both shrouds attached when stepping the mast.  The casting is threaded for the machine screw.  This style cap should be covered with a vinyl spreader cap to protect the sails.

HINT - "When the upper shroud is tensioned against the flat recess of the casting, it makes an abrupt turn over the top sharp edge of the cap as it goes to the masthead.  The turn over the sharp edge results in point loading of the wire.  To alleviate the point loading, round off the top of the recess with a small round file, leaving the metal smooth with the correct radius to match the wire diameter.  There you go, good for a few more miles through the Southern Ocean!"

LATE VERSION SJ23 SPREADERS - At the outboard end of these spreaders is an aluminum casting with a cap that fits snug over the upper shroud.  The shroud must be secured under the cap to keep a slack leeward shroud captive while stepping the mast or when sailing. 

Positioning the cap along the shroud is a bit of a juggling act.  With the mast horizontal and the shroud tightened, push the spreader up a bit then tighten the cap.  When the turnbuckles are tightened, the angles above and below should be equal and the compression force on the spreader will be directly in line with it.  If they aren't, move the cap up or down accordingly.  You'll know it is correct when you can just slip the spreader over the stub.

When a spreader bisects the angle to the shroud (highlighted in photo), the compression force on the spreader is balanced (directly along the spreader).  It should go without saying that the port and starboard angles of the spreaders must be identical.  Unequal support may result in spreader collapse followed by mast failure. 

WIRE/ROPE HALYARD WEAR - Early version SJ23s all had wire/rope halyards to eliminate stretch.  The masthead sheaves have duel grooves to accept both.  Problem is, if the wire portion of the halyards are tied off at the base of the mast the wind will eventually whip them sideways.  The wire rubs on the spreaders, resulting in lots of wear over the years.  If you had no other reason to replace the meat hook laden halyards, then this would be it.  Jon Raymond

 TOP
 

MAST HEAD - The factory mast head is cast aluminum that incorporates four sheaves with a nylon divider plate to separate the halyards.  I replaced Panache's divider plate with a thicker aluminum plate to replace the thin factory plate.  The factory rope/wire halyard wore a slot in it that snagged the line.  This the most compelling argument for converting to an all line halyard. 

About the only thing you have to maintain here are the nylon halyard sheaves.  I've inserted brass bushings in mine and oil the bushings annually.  These sheaves spin over a 1/4" stainless bolt.  Just inspect them for wear and replace if they fit sloppy.  You could upgrade them to ball bearing sheaves and be done with this maintenance but that's no fun.  Buy a UV resistant sheave so it is not subject to deterioration from the sun.  I'm still sailing Panache with the factory sheaves.  See Tech Tip F03 for sheave info.

The SS pins for the fore and aft stays are equipped with cotter pins outside the head.  This is absolutely mandatory to ensure they don't fall out and the stick stays standing.  Bend the cotter pins back fully around the pin.  Also check the rivets for tightness to the mast extrusion.

Notice that the VHF coax and a Windex power cables go through small holes I drilled through the top of the cap.  This keeps the cable straight, eliminating stress due to a cable bend below the cap.  Silicon sealant is jammed around each cable to insulate and eliminate chafe. 

As for this Windex, someone dared me to make a working unit from broken parts, claiming it couldn't be done.  The mid block is a piece of UHMW that houses the bearing.  The black rod is an aluminum arrow shaft with the target tip at the front and some very thin sheet aluminum vanes epoxied to the back.  The tricky part was gluing the weights inside the shaft at the correct balance point.  So far this "Windex" has worked for 25 years.  The set screw goes into the slot around the bottom of the shaft.  This minimizes the chances of loosing the Windex if the screw is loose.   TOP
 

Return to Tech Tip Index. . . . . . . . . . . . . . . Have a Question?