A Leveraged Solution

 Mast Progress

The mast is receiving some finishing hardware.

The masthead light is installed on the mast via the masthead plate.  I was not able to come up with a more elegant wiring arrangement.  The connection between the  yellow light lead and the white mast lead is protected by shrink tubing and a strain relieving cable tie through the masthead plate.  This arrangement should provide a reliable connections in a more readily serviceable location with no comfort given to aesthetics.

As mentioned in the last episode, the mast lead weight is held by clamping against angled surfaces on the masthead plate and cut into the masthead exit port.  This arrangement seems to be effective.

Two halyard blocks are installed in the aft mast crane.  These blocks receive lines that attach to the gaff spar at the mainsail head.  These lines raise and lower the mainsail as well as control the gaff's throat and peak positions.  The advent of high strength synthetic lines has revised the old practice of lashing on blocks rather than using metal fixings. 

The masthead plate extends aft to provide mounting spaces for a possible future masthead fly and/or a VHF radio antenna. 

New Skills

High strength synthetic lines are replacing stainless steel cables for mast rigging.  Synthetic lines are stronger than stainless steel, weigh less, do not corrode and are easier to work with than stainless steel cables.

No dimensions are given for the shroud lengths.  I checked my shroud length math two different ways to gain assurance my splicing efforts would result in serviceable components.  The ultimate test remains.

Dyneema shrouds have been constructed to support the mast.  YouTube provided instruction on how to make locking brummel eye splices which I sometimes need to review in spite of my practice.  It also covered whipping a line to secure a sleeve over another line or core.  Antishafe sleeves were whipped to the longer shroud loop sections.

Each shroud is composed of two parts.  The shorter, lower portion's large loop anchors to the hull's shear.  The longer, upper portion's large loop anchors around the masthead.  The thimbled shroud ends are joined by multiple passes of a smaller line ceased between the thimbles.  This arrangement is known as dead eyes.  It permits adjustment of the mast rake.

Above is an image of the mast crossbeam underside's dolphin striker.  This feature resists the mast compressive load on the crossbeam.  The dead eyes permit tension adjustment on the dolphin striker.  More research might be needed on ceasing knots.

The longer shrouds loop around the masthead and lead aft as shown above.  The forestay attaches to the loop joined by a clevis.  The roller furling headsail requires the use of an internal stainless steel cable forestay.  More about the forestay in a future episode.

Creature Comforts

I've began the process of accumulating items that will make life onboard more comfortable.  Two 12 volt electric fans were purchased, one for each hull.  These fans plug into outlets in the hulls as well as outlets in the cockpit.  The fans are equipped with suction cup mounts that will be replaced with a more versatile and reliable spring loaded clamp mounts.  The clamp mount will clip the fan onto bulkheads or other interior/exterior features for the best cooling effect.  The low current draw should permit these fans to run throughout hotter nights. 

I've also began to consider sleeping equipment like cots and mattresses.  It looks like up to three cots could be accommodated in the cockpit (a cockpit tent makes for a comfortable possible future arrangement).  Initially, a backpacker's sleeping pad could be the ticket.  These pads fold up into small bricks to store away.  I've slept in the boat without pads, but I'm not sure everyone could.  A fold up camping table could be a useful addition.  Any suggestions would be welcome.   

Long Standing Problem

The electric outboard motors normally have the batteries mounted on the motor shaft head.  The battery weight counters the submerged motor weight so that it is easy to raise and lower the motors.  There is not room to for the battery on the motor shaft head when located under the cockpit seats so the batteries are mounted beside the motor shaft pivot axis.  Without the battery counter weight it is difficult to raise or lower the motors in a controlled or easy manner.  Several iterations of motor lifting tools were necessary to arrive at something that was simple and easy to use.

Above is one iteration that used a hook to support the motor shaft underside as pressure is applied to the offset lever arm.  There is limited space in the motor well so the freely moving hook is tricky to put in position for use.  The hook can only be placed around the shaft when on the outboard side so the hook and the removable offset lever arm must be reconfigured when operating on the second motor.

Two lever arms configured for starboard and port with fixed hooks might have been a solution, but then there is more stuff to carry around.  The search for a better solution must continue. 

The simplified solution uses a clamp around each motor shaft.  A hook on the lever arm engages a clamp through bolt to lift and lower the motor.

The taped up hook projects from the lever arm end.  A long slot cut into the lever arm end receives the 1/8" stainless steel, epoxy slathered, hook plate.  Two holes are drilled through the lever arm and steel plate to receive 1/4" pins that take the load applied to the hook.  This lever arm end is sheathed in carbon fiber for a hopefully long service life.

The motor shaft clamps have a teardrop shape to match the shaft profile.  A perfect fit around the shaft was achieved by wrapping the shaft in cellophane tape to prevent epoxy adhesion.  The clamp mating surface was coated with thicken epoxy before allowing to cure while clamped around the protected motor shaft. 

The clamps are sheathed in fiberglass to resist water intrusion.

Here we have a look down into the starboard motor well.  To the right is the lever arm engaged with the motor shaft clamp.  Once the lever is engaged with the clamp, the lever arm is unlikely to fall into the water as with earlier iterations.  The motor can now be lifted out of the water by pressure applied to the lever arm.  I resisted cutting a slot in well covering for a long time, but the next image will show the need to accomodate an offset lever arm.

Here the motor is latched in the up position.  The offset lever arm to clears the locker combing and the mast crossbeam.  Note the gap between the shaft clamp end to the right.  This gap allows the lever arm hook to pass under the clamp through bolt.  This motor lowering and raising arrangement is quick and easy to use as long desired.

Mast Man

The mast was left with the cross section of a hollow octogone in the last episode.  It is time to make it a round cross section.

More Facets

A five inch diameter disk was screwed onto the mast head to define lines turning the octogone into a sixteen sided polygon.  One facet of the sixteen sided polygon has been cut along the mast length in the above image.  The mast end and disk was sniped in this first effort.  Future cuts would use a hand plane at the ends to avoid such snipes.

A rule is placed against the disk to determine the dimension, equal distance from the apex, that defines the edges of the new facet.  A template was made to mark this dimension on either side of the apex along the mast length.  A line then drawn with straight edge, from mark to mark, defined the facet edges.  A powered plane roughed out the material between the lines followed by hand plane refinements.  I later learned there are better and easier ways to mark out the facets, but this is the method I used.  

Rounding the mast has created the most sawdust in this whole boat build.  I shall be chasing out sawdust from these operations for years to come.

Rounding

The newly created sixteen sided polygon required a round of sweeping before continuing with mast rounding operations.  An inverted sanding belt was placed around the mast and driven by a drill motor powered drum.  A length of pipe, slipped over the drive shaft offered a hand grip on the drum side opposite the drill motor.  This was a little tricky to operate but was manageable with some practice.  The facets merge into roundness as a finer sawdust re-permeates the entire shop.

Initially a smaller diameter drive drum was used that could not overcome the sanding belt friction against the mast.  A drive drum diameter similar to the mast diameter provided the solution.  The drum was wrapped in duct tape to improve traction with the sanding belt.  A day and one half effort with this tool produced the rounded mast.

Sheave Boxes

The plans call for a curved surface to be cut through the masthead for lines (halyards) to run over while raising and lowering head sails.  I chose instead to use a sheave box on the fore and aft masthead faces so the halyards will not chafe against a static curved surface.  The sheave axle is only captured by insetting the sheave box into the mast.

 A fare amount of work with a router, a drill and mostly a chisel produced the inset cuts need to receive the sheave boxes on both mast sides.  

Masthead Crane

The main sail has two halyards to position a gaff spar in the sail's head.  This requires a masthead attachment point for two blocks to receive the halyards and direct them down to the gaff.  The attachment is a thickness of plywood epoxied into a slot cut in the masthead.  The blocks are lashed to a hole cut through the plywood crane projecting past the mast circumference.  A later image will show this crane feature.

Cutting this slot required the router fixture shown in the image above.  The fixture is held to the mast by wedges pressing against the mast and oversized holes in the white mounting fixtures.  Raised edges, on the surface the router rests on, control the slot width and length.  A similar smaller fixture was used for the sheave box insets.

 The router fixture worked very well creating this large deep slot.

Masthead Plate

The masthead will be covered with a stainless steel plate for mounting the navigation/anchor light and other future items.  Power leads supplying the masthead mounted items must be clamped so the lead weight does not placed loads on electrical connections.  To that end the conduit lead exit points have been modified with upward sloping slots that keep the leads below the masthead plate.  The sloping slots also inhibit water from entering the conduit runs.

Here the navigation/anchor light is mounted on the masthead plate top.  Wedge shaped blocks are epoxied to the underside and fit into the masthead sloped slots.  The screws, supplied with the light, are just long enough to barely start into the light's threaded base.  I need three longer screws, but I could not source them locally.  The next shipment will supply me with 100 screws, I'll be set for a lifetime!

The masthead plate is installed on the masthead top.  The plate's wedge blocks will be cut down and allow electrical leads to pass underneath.  A clamping force is provided as the masthead plate is screwed to the masthead.

Sheathing

I could look at the above image and wonder "What kind of animal is this?".

The mast was sheathed in carbon fiber fabric and coated with a fairing compound.  The mast was supported in three places to maintain straightness as the epoxy cured on the fabric.  Wheels supported the mast so it could be rotated as sheathing was applied.  The sheathing was applied in stages so the wheels would not run on wet epoxy and become adhered to the mast.  The wheels were later repositioned to run on a cured area while maintaining straightness so additional fabric could be applied.

I considered using a carbon fiber sleeve to sheath the mast all at once, but this would be an intense amount of work for one person at one time and the wheels might become bonded.  I wonder if this conductive fabric might limit the effectiveness of the internal radar reflectors.  This tall conductive stick may also increase the chances for lighting strikes.  I could fret about many things, but rest easy knowing I have a strong long stick.

On the right end is the mentioned masthead crane where the main halyard blocks attach.  The four horn shaped projections restrain the mast support shrouds that loop around the mast and extend down the side opposite the horn to anchor on the hull shear (hull upper edge). 

Completed Mast

The mast has received two coats of primer, three coats of top side paint and two sheave boxes.  The mast construction is done and I await an additional hardware shipment to raise the mast on the boat for the first time.  That will be a tale for the next episode.

Who was that mast man?