Mast & Rigging Checklist
Halyard Sheaves Check for wear on sheave pins and bushings. Wire halyards can cause chafe on sheaves and masthead plates. Check headstay and backstay pins for excessive wear. If you have external spinnaker halyard blocks check the U bolts and block shackles for wear. If you use wire halyards consider changing these to rope. In most cases the sheaves do not have to be replaced in order to change halyard material. The only case where the sheaves will need to be replaced is if they have double grooves for both wire and rope. That sheave design is more common in boats 15 years and older. Changing to rope halyards can prevent wear inside the mast on through bolt tangs, excessive wear on the front edges of spreaders and can prolong the life of the exterior finish on the mast.
Shroud Tangs- There are two types of shroud tangs, internal and external. Internal tangs mount inside the mast and depend on the single mast wall for strength. External tangs mount on the exterior of the mast and are connected through the mast extrusion to the opposite tang by means of a threaded tie rod or bolt thereby relying on both mast walls for strength. The external tangs should be inspected for corrosion and the mast wall checked for elongation on the bolt hole. If the tangs are made for marine eye or fork fittings on the rigging ends then these clevis pins need to be removed and inspected. Replace cotter pins when reassembling. The most important examination on these type tangs is to check the bolt that connects these two tangs. Internal halyards can cause wear on these bolts and have been known to cut through a bolt causing mast failure. When performing a check on these tangs make sure that the mast is lying on its side and the halyards are pulled tight so that when the bolt is removed that the internal halyards stay on the proper side of the bolt. If the mast is setup on its front or back the halyards will fall to the front or back of the mast perhaps on the wrong side of the bolt and therefore causing wear on those bolts or halyards.
Socket type and T tangs need little inspection. In either case slide the shroud up and away from the socket or remove the T fitting from the T tangs. Visually inspect and clean the socket type as necessary. Check to make sure that the T tang is not loose. Most of the T type tangs are held in place using rivets and rivets can loosen in time. Refasten the T tang by installing new rivets if necessary. The socket type tang is normally integrated in the spreader root and should be inspected for corrosion and excessive wear.
Some of the older rod rigging assemblies used aluminum tie rods to connect the tang caps. These tie rods are susceptible to wire halyards. The tangs are removed by rotating the tang counter clockwise with the rod perpendicular to the mast wall. Corrosion between the aluminum tie rod and the stainless steel tang may make disassembly impossible.
Spreaders Check spreader inboard and outboard ends for cracks and wear in clevis pin holes. Also inspect the front edges of the spreaders where wire halyards can cause excessive wear and damage to the aluminum. When storing your mast with the spreaders attached beware that water can collect inside the spreaders, freeze during the winter and split or bulge the spreader.
Halyard Exits If you have internal halyards the exits may become chafed from wire halyards. Inspect each exit as this type of wear will destroy the rope tails on the halyards.
Goosenecks The boom and the boomvang goosenecks should be inspected by disassembling the swivels. Inspect for excessive wear on the lugs and the swivels.
Mainsail Track- Inspect for excessive wear, loose fasteners and loose joints in the track. Many masts have damaged track where the headboard car lives while sailing.
Lights & Wiring If your mast has old or damaged wiring it should be changed. Stray electrical currents cause short circuits and electrolysis. If you have a mast mounted VHF antenna that uses a S.S. bracket consider completely isolating the mounting bracket from the mast wall. This requires mounting a non-metallic isolation block to the mast wall and then mounting the bracket to the isolation block. No fasteners can pass from the S.S. mount to the aluminum mast wall as this will complete the electrical circuit. If the S.S. mounting bracket is attached directly to the mast wall this may be a source for stray electric current and electrolysis.
Rigging Wire and rod rigging needs yearly inspection. Wire rigging should be inspected where it enters swage fittings. The wire strands can become brittle or corrode in the areas directly next to swage fittings. Rod rigging needs to be inspected at tangs and fittings. Check for bends next to fittings. Older rod rigging utilized ball fittings on the upper ends of the rods. Time has proven that rods can fatigue directly under the ball fittings. Updated fittings have tapered stemballs that help distribute the bending loads along a greater distance of rod thereby reducing fatigue at the fittings. There are no good means to visually determine if your rods are fatigued. If your rigging has these balls cold headed on the ends of the rods you should consider changing these fittings to the stemball type.