SJ23 Tech Tip F03, (Updated 2019-07-17) Bob Schimmel


Internal Halyards Lead aft to Cockpit.

INDEX - Masthead, Halyard Exit Plates, Mast Foot, Deck Turning Blocks, Internal Halyards
Rope Clutch
, Replace Halyard, Line Length, Halyard Shackle, Loose Halyard, Cross Sheeting, Wash Lines.

The San Juan 23 was originally equipped with two wire/poly halyards, one for the main and the other for the jib.  The main halyard ran from the deck up the front of the mast, over both starboard sheaves in the mast head, to exit aft down to the mainsail.  The jib halyard ran in the opposite direction over the two port masthead sheaves.  A nylon dividing plate between the sheaves creates port and starboard channels to separate the halyards and keep them over their respective sheaves.  It is real annoying when a halyard jumps off its sheave and snags on a worn plate.  You may be able to free the halyard by pulling it back but sooner or later you will have to climb the mast to release the snag.  A recent inspection of the spreaders reveals that the wire portion rubbed metal off the forward and aft sides of the spreaders when the halyards were clipped to the foot of the mast for storage in the slip.  This must have made quite a racket and I can't understand how the previous owner lived with this.

In 1993 I converted Panache's original halyards from external to internal to reduce windage, eliminate halyard slap and to convert the original wire/rope halyards to all rope to eliminate meat hooks.  While there is a certain romance listening to halyards slap against the mast, it sure is difficult to sleep with the racket.  I really don't care if the racket comes from my boat or another, I still can't sleep with it.  I also like the clean look of an uncluttered mast.  I installed two jib halyards for wing-on-wing sailing or quicker sail changes and one halyard for the mainsail.  This leaves the port aft sheave vacant for a future boom topping lift or other necessary toy!.  All my halyards are colour coded 3/8" polyester prestretched line.  The following steps describe my modifications.


The factory masthead sheaves are designed to handle 1/8" halyard wire spliced to 3/8" rope for the wire/rope halyard the SJ23 was originally equipped with.  I see no point increasing the line size and weight aloft.  At the time of this upgrade no maintenance was ever done to Panache's nylon sheaves for 26 years since new from the factory.  The sides and face were in good condition but the bearing holes were worn oblong.  I had no idea where to find replacements so decided to insert a bronze bushing into each sheave to restore them.  I chose a bronze 1/4" ID x 3/8" OD bushing.   This is quite easy to install by drilling out the oblong hole with a drill press and pressing the bushing into the sheave using a bench vice or a bearing press.  The bushing must be pressed with machine precision in the hole to fit snug without stretching the sheave.  If the sheave is strained it will crack during the first winter freeze.  Cut the bushing to length so it just protrudes out the sides of the sheave.  I soaked the bushings in oil prior to pressing them in.  They get a dose of oil every time the mast is lowered, if I don't forget.  The oiled bushing reduces the internal friction of a sheave and greatly reduce the effort to raise a sail.  No more sticky operation and a sail drops very quickly.  
The factory sheave is approximately 1 3/4" in diameter, 7/16" wide with a 1/4" hole.  Replacement sheaves are available today from various chandlers.  Best to order the sheaves equipped with the hard Delrin ball bearings. 

Panache's mast head nylon dividing plate had a V-groove worn in it from the wire halyard rubbing against it.  Occasionally the plate snagged the wire halyard which I had to release by climbing the mast.  "While I have no fear of height, it isn't fun being at the masthead of a small boat rolling in the waves.  Later I fabricated a pole with a tapered wire hook to snag the errant halyard while standing on the spreaders.  Much better."  It didn't take long to tire of retrieving it so replaced the nylon plate with a full length 3/16" thick aluminum plate.  This is thicker and tougher than the original plate so it will last forever.

I also replaced all cotter pins associated with the mast head and standing rigging.  The ends are twisted back around the pins to prevent a snag.  Bend them only once. 

"The SJ23 masts for the New Bern hulls were built by Kenyon Marine in Guilford, CT.  They should have replacement sheaves.  Tom Hukle at Yacht Riggers in Seattle, was the mast builder for the SJ23s in the west but he basically assembled the parts shipped from Kenyon.  If that is too much hassle, either West Marine, Binnacle or other chandler, etc. should have them.  Catalina Part #R6075.  Specify wire or rope sheaves:  Wire sheaves have an additional inner groove to fit the wire which will cause excessive load on an all rope halyard."  Best regards, Glen Moore, Seattle.  (Glen used to rig the masts when the factory was operational).  TOP 


The halyards must exit somewhere near the bottom of the mast so I installed four Schaeffer stainless steel halyard exit plates spaced equally apart (alternate sides) along the bottom five feet of the mast.  If they are installed at the same level, opposite each other, it will cripple the strength of the mast.  The 2 jib exit plates are on one side of the mast and the main exit plate is on the other.  The spinnaker is on the front.  One of the exit plates is shown at left.  
The exit hole was cut oval to match the fitting and to retain maximum strength.  The edge of the hole was filed glass smooth to protect the line.
Each plate has sealant under it to prevent movement and marine growth.  While cutting a hole in a mast always has the potential for weakening it, Panache's mast has survived two knockdowns with no damage.  

At right is the factory foot casting equipped with exit blocks on Art's boat.  This option was designed for racing.  Since the mast rests on top of the casting the mast strength is not compromised with exit holes, which creates peace of mind.  Notice that the pivot feature for stepping the mast is retained via the pivot plate at the base of the fitting.  The structural strength (for stepping the mast) is retained via the four bolts into the top of the casting.  You can see 2 of them in the photo at right.  If you add this casting to a standard mast, remember to cut the mast shorter to allow for the length of the foot casting, otherwise the standing rigging will be too short.  Now wouldn't you look silly stepping your taller mast in front of all those marina fossils lounging in the peanut gallery!

Factory castings are available from Spar Tech.15230 NE 92 St, Redmond Washington 98052, 425-883-2126 or San Juan Sailboats.  Had I known about this fitting I would have bought one and saved a lot of time and effort by not having to install the exit plates, make a mast base plate, and equip it with mast turning blocks.  But then, what else would I have done with my time!  If you use the casting from an SJ24, you will have to install a wedge under it to compensate for the sloped deck of an SJ24.   TOP 


I fabricated a heavy gauge stainless steel plate to install under the tabernacle or mast hinge to attach Panache's halyard turning blocks to as shown at left.  At right is another variation on Artful Dodger.  The deck hinge plate is 3 7/8" x 6 3/4".  Make each upturned tab about 1 1/2" wide and the full length of its respective side.  Drill four 3/8" holes through the port  and starboard tabs to mount the halyard turning blocks to.  Drill a couple of holes through the forward tab to mount spinnaker halyard blocks or anything else you can think of.  Then drill holes through the base, aligning them with the tabernacle mounting bolts.  Prior to assembling, scrape the surface clean, drill the mounting bolt holes oversize, fill with epoxy, fill any other cracks, drill to correct bolt size.  Then clean the surface with acetone, spread a light coat of butyl rubber over the deck contact area, push the tabernacle to spread some of the sealant, circle seal the bolts and snug up the nuts.  Drag a popsicle stick across the bead of sealant that oozed out to make a smooth round fillet to the deck.  This guarantees uniform support, no air holes under the plate, and no water leaks.  I did this job to Panache in 2001 and it hasn't leaked a drop since.

Many people are superstitious about loosing their mast and will place a coin under it for good luck.  However, under an SJ23 mast foot is NOT the place to leave your St. Christopher medal or other coin of choice.  The electrical valence difference of the metals will create corrosion, guaranteeing that the mast will come down!  Instead, fasten your coin to the inside of the mast base or stick it to the outside of the mast, at the base somewhere.  Just as long as the two different metals don't contact each other electrically to create electrolysis.  Get creative and make the installation look good.  Trust me, the gods will like it!   TOP 


Shown at right is Panache's first version deck hardware to guide the lines from the mast base to the cockpit.  There are three blocks on either side of the mast base.  Each is supported off the deck by a Harken block spring to keep it from flopping and in alignment with its deck turning block.  Without the springs, the blocks jam against each other which is a nuisance.  They are dead quiet now and always in perfect alignment for easy running. 

From the mast turning blocks the halyards go through a set of deck turning blocks to direct the lines aft to the cockpit.  Through bolt them to the deck so they are really strong.  Don't rely on wood screws as there isn't enough strength in them nor is the cored deck substantial enough to grip a wood screw.  Remember to seal the wood core inside the deck holes with epoxy and seal the bolt holes with butyl or Sikaflex. 

From here the halyards go through a short section of angle aluminum with holes through it to guide the lines around the front of the sliding hatch retainers.  I drilled three 1/2" holes in each and filed the insides smooth so they don't impede line movement or chafe the line.  They are my design.

Finally the halyards are held by a triple rope clutch mounted on the aft end of the coach roof with the free ends hanging in the cockpit.  As far as I'm concerned, a rope clutch is the best way to secure a line if you sail single handed.  They are quicker to set/release, generally never slip and have less wear and tear than a cleat. 

At the aft end of the coach roof, aft of the rope clutches, is a #6 winch and a cleat, in that order.  A #7 or #8 winch would have more power but is heavier.  While I've never had a problem with the rope clutches, I've retained the original cleat behind each winch as back up.  You can never be too sure.  Besides, it is a great place to clip my wet bathing suit to.  

UPDATE - In 2014 I upgraded this deck hardware to add four reefing lines and two more rope clutches as described in Tech Tip F05.  Some time before that I removed the solar panel mounting board on the deck, just aft of the mast.   TOP 


The technique of pulling the halyards through the mast is already described in Tech Tip E09.  I suggest you run the halyards through the space aft of the spreader compression bolt (between the spreaders) to direct them to the aft facing exit holes at the bottom of the mast or through the exit holes of the foot casting, if so equipped.  This reserves the front space for the electrical wires.

NOTE - Whenever I convert something, I seldom remove or dispose of the original hardware, just in case the conversion doesn't work.  This way I can restore to the original.  In my conversion to internal halyards I removed the mast cleats thinking they were unnecessary.  That was a mistake.  They are required to terminate the halyards for stepping the mast and were reinstalled a few years later.   TOP 


The simplest method of pulling a new halyard through the mast is to use the old one as a fish tape to pull the new one through.  Stitch the two ends together, aligning the butt ends snug to each other, then gently pull the old line out till the new line is in place.  The stitch technique will pull a line over a sheave or through a block and is particularly useful if you don't want to lower the mast.  

If the mast is down and you don't already have a line inside the mast then you stitch and pull a line through or make a fish tape to get the lines through the mast.  3/4" PVC tubing is excellent as a fish tape as you can push, pull and turn it through the mast with sufficient flex and control to get it around an obstacle.  Cut the end off to a 4" long taper to facilitate poking and prodding through or around an obstacle.  The spreader bolt, half way up the mast, divides the mast cavity into fore and aft sections.  Pull the jib and spinnaker halyards through the forward space and pull the main halyard and other aft lines through the aft space.  Once you've pulled a set through, stretch each halyard very tight and tie them to their respective side.  This temporarily keeps this set of halyards to its respective side, keeping the opposite side clear.  Then roll the mast over so the clear section of the mast is at the bottom and pull the second set through. 

After you've pulled all your lines through, loosen all halyards.  Then tighten each individually while looking inside the mast as someone shines a light down the mast from the opposite end.  This will verify that lines are NOT wrapped around each other.  THIS is ABSOLUTELY ESSENTIAL.  If you have a wrap, pull the two offending lines out till the wrap is exposed, undo it, and pull the lines back in again.  Use a light line to pull them back.  The object of this exercise is to have all lines straight and NOT wrapped around each other or anything else.  Wrapped halyards are a real nuisance as they CANNOT be tensioned or RELEASED properly AND there's not a bloody thing you can do about it on the water.  Once it is determined that a halyard is clear and free, guide it out of the mast through its assigned exit hole.  As a final test, temporarily install the cap and foot and pull each halyard (with the rest tightened) to feel if it is free to move.  They should all slide through the mast with minimal resistance.  You'll be able to feel and hear if a halyard is still wrapped.   TOP 



PORT (Note 1),


CABIN TOP, (#6 Lewmar winch & 5 position Easylock rope clutch)

CABIN TOP, (#6 Lewmar winch & 3 position Easylock rope clutch)

MAIN HALYARD (70' of 3/8" yl/bk tracer poly).
The mast is 26' 7" tall and the base is 8' from the cockpit. 

1st REEF - 3' deep.
    TACK (16' of 1/4" gn Dyneema)
    CLEW (24' 6" of 1/4" gn Dyneema).

2nd REEF - 6' deep.
    TACK (22' 6" of 1/4" red Dyneema)
    CLEW (31' 6" of 1/4" red Dyneema).  Tech Tip F05.

Read (Note 3).

BOOM VANG (20' of 1/4" bl poly).

1st JIB HALYARD (70' of 3/8" rd tracer poly).
2nd JIB HALYARD (70' of 3/8" gn tracer poly).
The forestay is 29' 3" long, mast is 26' 7" tall and the base is 8' from the cockpit. 

SPINNAKER DOWNHAUL (18' of 3/4" white nylon webbing).

Read (Note 3).


SPINNAKER HALYARD (70' of 1/4" wh/bl poly).
LAZY DUTCHMAN (25' of 3MM bl Dyneema)

Read (Note 3).

GUNWALE, (#10 Lewmar Winch & Cleat)

GUNWALE, (#10 Lewmar Winch & Cleat)

150% GENOA SHEET (27' of 1/2" wh/yl tracer poly).

110% WORKING JIB SHEET (35' of 3/8" wh poly).

80% STAY SAIL (32' of 3/8" bl)  Tech Tip F36.

CRUISING SPINNAKER SHEET (50' of 5/16" wh poly).

Read (Note 2), (Note 3).

150% GENOA SHEET (27' of 1/2" wh/yl tracer poly).

110% WORKING JIB SHEET (35' of 3/8" wh poly).

80% STAY SAIL (32' of 3/8" bl)  Tech Tip F36.

CRUISING SPINNAKER SHEET (50' of 5/16" wh poly).

Read (Note 2), (Note 3).


TRAVELER control line - (17' of 1/4" wh/rd tracer poly).  Tech Tip F28

MAIN SHEET equipped with 4x1 blocks,  (38' of 1/2" bk poly).  Tech Tip F28

BOOM TOPPING LIFT (~25' of 1/16" SS cable plus 2 blocks at the bottom with 4' of 1/8" Dyneema terminating in a jam cleat on the boom to make the length adjustable.

TILLER TAMER (8' of 1/4' rd poly).  Tech Tip E12.

OUTBOARD LIFT - (9' of 1/4" red poly) Tech Tip D01.

NOTE 1:  By convention the mainsail halyard terminates on the starboard side and the jib halyard on the port side.  However, one of Panache's previous owners installed the halyards opposite to this.  I can't reverse the installation without leaving ugly fill holes through the deck.  The arrangement works OK for me so I followed suit by adding the mainsail reef lines to port.  (eg: hoist, lower or reef the mainsail on port and similarly the boom vang, two jib halyards and the down haul on the starboard side).  Performing a job by standing in one place is quicker, easier and safer, especially in rough weather. 

NOTE 2 - You should leave a jib sheet long enough to cross sheet it to the high side of the hull.  You never know when the boat will heel excessively and going to the low side is an option you'd rather not exercise. 

NOTE 3 - No allowance is made for splicing in lengths listed above.  Buy appropriate extra line for this.

NOTE 4 -  If you install a new halyard inside the mast it is probably a good time to check the electrical wiring as well.  See Tech Tip E09.


3/16" = 5 MM
1/4" = 6 MM
5/16" = 8 MM
3/8" = 9 MM
7/16" = 11 MM
1/2" = 12 MM
9/16" = 14 MM
5/8" = 16 MM
3/4" = 19 MM
7/8" = 22 MM
1" = 25 MM

  • MAINSHEET LENGTH - A main sheet should be long enough to let the boom swing out against a shroud while leaving at least a 5' tail piece beyond the mainsheet block.  The length of the tail piece is a personal preference but it should be long enough to reach the helm while holding the tiller. This is also long enough for anyone else to operate the mainsail from inside the cabin or high deck.  The factory supplied line is 3/8".

  • JIB SHEET LENGTH - A jib sheet should be long enough to go from the clew on the leeward side, around the mast to the winch on the windward side of the boat, with at least 8' of line as a tail piece in the cockpit for pulling the sheet back for tacking.  I recommend 8' just in case you want to extend the sheet to a crew sitting on the high side behind you.  May as well use his body weight for something huh?  The sheet will be longer for a large overlapping jib.  This length should work with the jib sheeted in tight for close haul sailing or winged out for downwind sailing. The factory supplied line is 3/8".

  • LINE COVERING - I prefer the softer stuff that is easier on the hands.  Especially for the sheets.

  • LINE THICKNESS - I prefer 3/8" polyester for halyards and 1/2" for jib and main sheets.  You can grip 1/2" better without cutting through your skin, especially when your hands are wet.  However, my replacement halyards might be 5/16" to reduce weight aloft.  If you are real picky you could use 1/4" sheets for sailing in light air.  I did say picky! 

  • POLYESTER (Dacron) - Excellent for sheets as it has a bit of stretch for shock loading in a puff but not enough to loose the setting.  Excellent for holding a knot.  Stands up well to UV.  Expect 15 to 25 years of life depending on exposure to UV.

  • DYNEEMA or SPECTRA - Excellent for halyards, reefing lines or lazy jacks with each having special requirements as it applies to a halyard.  It is possible to remove a considerable weight aloft by using these light weight 1/4" fibre lines.  These fibres are so slippery that a knot will let go.  Therefore your only choice is to splice a loop in the end which is easy to do.  The best knot that works is a mobius brummel knot.  Look it up on the web.

    • Weight for weight, Dyneema and Spectra are up to 15 times stronger than steel and up to 40% stronger than Kevlar (c) (DuPont).  Stronger than wire cable of the same size.  Highest strength-to-weight ratio of any fiber.
    • Being slender for their strength, they offer less aerodynamic drag than other types of line.
    • More abrasion resistant than high carbon steel.  Highest abrasion resistance of any fiber.
    • Resistant to UV light.
    • Do not absorb water.
    • Exhibit very low stretch compared to nylon or Dacron lines 3 - 5 %.  (like comparing steel wire to rubber bands).
    • Easily spliced.
    • Floats.
  • ARAMID (Kevlar, Nomex, Twaron, Technora):

    • High toughness (Work-to-Break ratio).
    • High tensile strength at low weight, specific gravity: 1.44.  Lower compression strength.
    • Low elongation to break.  High modulus (structural rigidity).  Elongation at break is 1.5-4.5.
    • High cut resistance.
    • Low electrical conductivity.  This avoids electromagnetic interference cause by steel wires.  Because Kevlar wets readily it can conduct electricity when wet.
    • Low thermal shrinkage.
    • Flame resistant.  Self-Extinguishing Critical Temperature 4000F.
    • High chemical resistance, but is sensitive to chlorine.
    • Excellent dimensional stability.
    • Relatively poor compression strength.
    • Can absorb water.
    • Sensitive to shock loads and can fail unexpectedly during such.
    • Kevlar is sensitive to UV degradation.

    - You also have to consider the condition of the teeth on your rope clutch.  If they are just the slightest bit worn they may not grip the small diameter slippery line.  If a knot can't hold then it is unlikely it can stay wrapped around a cleat.  If you still want strong small diameter line then buy it with a Polyester outer jacket for grip and comfort.  A favourite trick is to strip the outer jacket from a Polyester line, slip it over Dyneema or Spectra and stitch it for grip and comfort.
    - A major point to consider is your hands.  Thin light weight line can cut your hands very quickly if you pull hard enough when hoisting a sail, especially if your hands are wet.  You'll be surprised to discover your hands bleeding because it happens so quickly.  The solution is to always wear leather gloves and use a winch to hoist the sails. 
    - If a light weight halyard ever goes astray in a strong wind, it will become airborne and be out of reach to retrieve it till the wind dies.  On a pocket cruiser it would be impossible to climb the mast during such wind.  DON'T let go of the line.

  • PENTEX® - This fibre has a higher modulus than polyester and exhibits approximately 30-40% less stretch than its polyester equivalent.  The PE line of fabric is an ideal choice for sails where low stretch is a top priority and aramid based fabrics cannot be used. Small diameter and light weight for its strength. 

  • SPECTRA - Very light, strong and slippery line.  Will stretch a bit under load.  Stands up to UV very well.  Excellent for halyards.  Poor for knots so it must be spliced.  Small diameter and light weight for its strength. 

  • KEVLAR - Very little stretch.  Poor protection against UV.  Expect only 4 to 8 years of life.  Small diameter and light weight for its strength. 

  • CARBON FIBRE - This stuff is used on America Cup boats.  You can't afford it!   TOP 


It's my experience that the very convenient jib halyard snap shackle shown at left has a tendency to let go at the most awkward of times; usually with somebody watching.  Therefore I've stopped using it.  If you enjoy climbing the mast, then fill your boots!  The problem stems around the ring or pull knob that protrudes beyond the edge of the casting.  You can be rest assured that it will snag on something and release, sometime!  What a pain.  While a pull knob might snag fewer times than a ring, it is also more difficult to grab.  I'm told that a Wichard snap shackle has a bullet proof design but it is also very expensive.  A solution that some manufacturers use is to slip a vinyl or leather sleeve over the top end of the snap shackle.  The sleeve just covers the release pin to protect it and maintain speed of operation during sail changes.  It may not be easy to operate in cold weather but if it works why not.

The style of halyard shackle (Ronstan RF1032) shown at right doesn't let go.  It is equipped with a pin that separates the halyard from the sail to prevent loss or jamming.  This pin is removable so it can be slid on a line equipped with a spliced eye.  The lever style keyed locking pin is relatively easy to operate with cold fingers and can handle a large load.  It stays latched in the detent.  In fact I don't know of anyone who has experienced a release on a jib.  While this release problem is not so prevalent on the mainsail I see no reason for restricting such a good device to the jib.  Install one on the mainsail as well! 

MARK a HALYARD - You should mark your jib halyard to know when the genoa is at the mast head.  Also mark your main halyard for each reef point.   TOP 



Those inconsiderate people who leave their halyards slapping against the mast at night deserve to have them cut!  That's my personal opinion and I'm sticking to it!  I know of many others who share my opinion. 

When I spend a night in a marina, one of the first thing I do is listen for slapping halyards around me.  Then I flip it around the spreader or secure the bitter end to a point away from the mast, finally tightening it so it doesn't move.  If I keep the halyard attached to the mainsail then I'll use a strap to my flag halyard or shroud to secure it.  In either position it can't slap against the mast. 

I like marinas that enforce this.  Who can sleep with that racket all night?     TOP 


All the previous discussion in this Tech Tip describes restoring the running rigging in a standard configuration.  I have added this section since few people are aware of the benefits.

If you intend to race the boat successfully or sail in really heavy weather, then you should give some consideration to running the jib sheet across the cockpit to the windward side.  You can do this temporarily by taking a turn around the idle leeward winch and across the cockpit to the windward winch.  This is a good technique to use if the boat starts to heel towards 300 and you want to counter balance the heel by staying on the high side.  It is much easier to grind a winch on the high side than the low side, especially when sailing solo.  I do this regularly in heavy weather as a safety factor to keep from being dumped into the drink by a wave I didn't anticipate.  For this capability the free end of the sheets must be long enough to reach the windward winch, plus a bit more!

At least one person I know has rigged his SJ24 permanently by moving the primary winches from the gunwales to the cabin top and installing large turning blocks on the gunwales where the winches came from.  The sheet is run through the turning block and then across the cockpit to a winch located on the windward coach roof.  The benefits are that a crew grinding the jib sheet on a cabin top winch has their weight close to the maximum girth, helping to keep the boat upright for more drive and frees up valuable cockpit space.  By being further forward they maintain fore aft trim and the helmsman is free to concentrate on steering without interruption.  Additionally, the extra leverage that can be applied to the winch while positioned securely on the high deck is significant.  In summary, if the trimmer can stay forward, to windward, and out of the cockpit, he is contributing all the key factors to sailing a San Juan fast.  The overall effect can be more dramatic than you realize.  However, if the weather is really light then it is advantageous to induce some heel, so have the grinder stay in the companionway.   TOP 


  • To prevent snarling the line in the washing machine, put each line in a mesh bag.
  • Wash on the gentlest cycle.  Power washing is not recommended.
  • Wash only with a mild detergent.  Don't ever use bleach. 
  • Fabric softener is OK at recommended doses.
  • Hot water is OK.
  • Avoid contact with acids, bases and solvents.
  • Air dry lines.  Don't dry with heat.

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