Seeking the Zen of Sanding

 The last episode pioneered presenting the completed component first, followed by discussions of the details.  This led to no great out cries and may contribute to comprehension of my efforts.

You may recall from the last episode that crossbeam progress was limited by the epoxy and lumber supply.  Two of the four crossbeams were constructed up to a point requiring vast quantities of unavailable epoxy.  The lumber shortage remains, but the epoxy shortage does not.  We'll pick up beyond where we left off.

Mast Crossbeam

This 14' 9" mast crossbeam will be located just forward of the cockpit.  It is the longest and most complicated of all the beams.  It has been enveloped in fiberglass and hand sanded.  The mast step is located on the beam's top center.  The step distributes the mast compressive loads onto the beam structure.  A dolphin striker, not yet installed, counters these compressive loads on catamarans.  To either side are semi-circular access ports located near the points where the beam is lashed to the inboard hull sides.  These ports allow access to anchor points for high strength synthetic line to pass through a hole, in the beam underside, to a centered standoff (not installed) three inches below the beam.   The line then returns inside the beam to attach to the opposite side anchor.  Tension on the line distributes the mast compressive forces to the hull attachment points rather like an upside down suspension bridge.

If you look carefully at each end you will find a cleat.  These cleats will be used for bumpers, springer lines and a future cockpit tent.  

I learned late in the process that the beam work was much easier on the saw horses rather than the bench.  I could access all sides and roll it over as required while completing the endless sanding seated.

The first task is to complete the five full length fillets along the beam's length.  These fillets reinforce the bonds between the 3/4" plywood web and other components as well as providing a smooth transition for laying fiberglass.  Of course these five full length fillets will require sanding by hand before fiberglassing is possible.  Here the yellowish fillet is reinforced with a three inch wide strip of fiberglass along its' length.  The gussets and other beam interior surfaces have received the finial coat of epoxy before a fairing will cover these surfaces.  Beam areas epoxied to the fairing are sanded as well.

  

Cutting out a fairing requires a template.  A strip of 3/8" plywood spans half the fairing width and is wire tied through gusset holes, conforming it to the fairing curve.  Small sticks are hot glued to the plywood to define points along the fairing edges.

In the first attempt at this, I used a piece of limber lumber that distorted when the wire ties were tightened.  This resulted in a fairing half that did not fit and I have no material for a redo.  I was lucky to find it could be made to work on the other end with some extra labor.

The template is laid on the fairing material and marks are transferred from the stick ends onto the material.  Nails are driven into these marks and a batten is clamped to the nails.  The batten creates a smooth curve that a line is drawn against to define a cut line.  

Works like a champ!

The fairing is faired.  Notice the outlined area on the lower left beam's end.  This wedge shaped area is a sixth epoxy fillet running the entire length.  It may have taken a week to complete as only so much epoxy can be applied and still maintain its' shape until it sets.  Of course sanding is required before each epoxy application.  I considered using wedge shaped lumber to fill much of the void, but thought it would be too much of a juggling act as the wedge and fairing are best adhered at the same time.  The wedge idea will be revisited on the next beam.

A early image of the inspection port and cover for the dolphin striker anchor.  The anchor is a 3/8" stainless steel bolt passing through two and one half inches of lumber to an imbedded nut.  As with all fastener holes, the holes are drilled over size and then filled with a high density epoxy.  The filled hole is then drilled to fit the fastener.  This arrangement prevents a pathway for water to enter the wood as well as provides better bearing surfaces for through fasteners and threads.  The inspection ports and covers received epoxy filled fastener treatments for all six cover retainer screws.

The first post fiberglass sanding in progress.  Hand sanding produces troublesome callouses where the finger nail edge meets the flesh.  My callouses from sanding the hull were just beginning to sluff off when I again had to seek the zen of sanding in the beam construction.  The taped up fingers offer some protection, but are not the hot ticket.  One taped finger tip I've learned is to use the regular cream colored masking tape as it will not unravel like the shown blue painter's tape.  This may be the first post fiberglass sanding, but not the last before the beam is fully completed.

Aft Crossbeam

Surely, some may find endless amusement in my trials by sanding.  I must soldier on to achieve the goal of beach bars and bikinis for evermore.  To that end, the 14' 4" aft cockpit beam construction is well underway.  The full length epoxy fairing fillet will soon be ready for shaping by sanding.  The wooden wedge filler idea was abandoned as the available lumber would not permit me to keep my fingers while making the cuts.

Painted Hulls

Then there were two...  Epoxy primer and top side primer arrived on a recent shipment.  This enabled the application of top side paint and antifoul paint on the starboard hull.  It has been unusually cool for late spring and early one morning I was able to apply one coat of topside paint that would flow out to a smooth finish.  Additional coats will be necessary, but that will have to wait for cooler times.  

The hull was inverted for the painting process.  It is always a dicey process inverting or righting a hull.  The hull suspension/rotation lines are beginning to show signs of fraying.  I hope I have inverted the hulls for the last time, but this may mean that at some point I'll be lying on my back and reaching up to sand a hull.  Ugh, where is the zen in that?

Shortages

I thought my build descriptions might be clearer if I provided images and descriptions first of the end state, followed by details leading up to the end state.  If a person knows where a story is going, then it should be easier to recognize and understand the pieces in the detailed discussions.

The inverted starboard hull now sports a faired (smoothed) fiberglass sheathed hull with one coat of below the waterline grey epoxy primer and one coat of white topside primer.  I'll need more epoxy primer coats before applying three coats of antifoul black paint.  I ran out of the epoxy primer and moved the waterline masking so that I could begin applying the topside paint.  I applied one topside primer coat to discover more was needed.  I`ve been slacking on keeping the materials coming.  The shipping company shuts down for a month around the first of year and Belize now has a stevedore strike.  My hopes for applying topside paint before it is too hot for the paint to level out may be dashed.

The bare plywood hull first received fiberglass along the keel and skeg.  Later fiberglass is laid to cover each hull side while overlapping the keel.

The hull is faired and the waterline is masked off to receive the below waterline primer.  The rudder is temporarily attached so the waterline can be established on it as well.  To the right is a leveled batter board, a similar batter board is at the bow, at a prescribed vertical distances from the decks.  A fishing line tensioned between the batter boards can be positioned close to the leveled hull so that waterline defining points can be plotted along the hull's length.  A more complete description of this and the fairing process is given in a previous episode.

The keel under the chocolate colored areas received three layers of heavyweight 1708 fiberglass and a higher density fairing compound for improved abrasion  resistance. 

I enlisted the help of a neighbor friend to complete the laborious fairing job.  This includes applying and sanding three coats of epoxy fairing compound over the entire hull surface by hand.  I recruited the right guy as he is a sanding machine where I tend to sand less vigorously.

On the inboard hull side I've made provisions for a depth/fish finder transducer.  This black clothing iron shaped transducer is intended for transom mounting, but this hull doesn't really have a transom and the more traditional transducers use through hull fittings.  I don't like the idea of though hull fittings and it would not work with this hull and transducer shape.   The transducer could be mounted on a submerging pole, but that arrangement seems prone to damage.  This arrangement allows for transducer replacement while keeping the wiring protected.  In this case I would say, "There is no perfection, only compromise".

The transducer connects to a black box that transmits over WiFi and is compatible with my mobile, GPS position, tablet based chart plotter.  Other crew can download the phone app to maybe find a dinner fish.

The transducer cable runs through PBC pipe cut lengthwise so that the cable connector can pass between the hull and the pipe.  Below the waterline (above the blue tape) layers of thin wooden straps are epoxied to the hull and pipe section.  This builds up a ramp section forward and aft of the pipe that once faired and fiberglassed, hopefully produces a good hydrodynamic shape.

The transducer mount is built up from laminated 3/4" mahogany.  An adhesive will secure and seal the transducer to the mount.  Replacing transducer likely requires destroying it, which is of no consequence, if being replaced.

A heat gun conformed the pipe to the hull curve.  Sticks pressed against the wall forced the wooden laminations into the curving hull shape.

With my painting ambitions vanquished I determined I have enough materials to build two of the four crossbeams that tie the two hulls together.  This is nearly completed beam will locate just aft of the cockpit.  It is very similar to the longer mast beam forward of the cockpit.  This beam face will receive a 1/4" plywood fairing to complete the beam`s triangular cross section.  Many additional fillets will need to be made before the fairing can enclose this structure.  And that will have to wait until I'm epoxy rich again.

This beam side faces the cockpit.  The cockpit hangs on the beam`s lower ledge.

The beam cross section is like an I beam with a 3/4" plywood web and flanges made of 3/4" mahogany.   Note that the cockpit side has two thicknesses of mahogany.  Fillets are yet to be made that will strengthen the web and the thickened flange's bond. 

Here we see the beginnings of the beam`s underside.  The mahogany flanges are epoxied to the 1/4" plywood base leg.  The base is ventilated with wide rounded slots cut through the plywood to help prevent rot(?).  The base is wide in the center and tapers towards the ends.  This requires a large variety of hole sizes to be drilled between the flanges.  I am fortunate to have a fly cutter to cut large holes at fully adjustable sizes.  This single cutting point tool is seen chucked in the drill.  It can be a wild ride making a large hole with a single point tool using a hand drill, but no work was destroyed this round.  The slots are finished by means of a router patterning bit following the flanges to connect adjacent holes.

I wonder at leaving the slots open as africanized bees have been reported in my neighborhood.  The openings may make a good home for many undesirable creatures, but the incorporation of screens will wait for another time.

This is the beginning of the second beam construction.  This beam will be located forward of the cockpit and support the mast.  Here the second 3/4" flange is epoxied to the top surface of the beam's base and the curving 3/4" plywood web is clamped into position as epoxy cures. 

The beam's underside outboard ends will rest on locating blocks built into the hull.  The converging 3/4" flanges create a wedge shaped void above the locating blocks where water can become trapped and promote wood rot.  A wooden wedge shape now fills this void to avoid this potential failure mode and provides a suitable surface to mount locating blocks.

I enjoy construction of the new pieces, but I'm developing numerous loose pieces that can't be installed for various reasons.  The problem is where to put all the loose pieces and the increasing resemblance to a hoarder's home, with little pathways leading from one section to another.  If this condition should invade my upstairs living quarters, worry for me.

Weather Tightening

 

This image is late breaking news from the last episode.  Here the smoked acrylic portlites are put in place and the hull on dolly is pushed away so I can get my first good look at the vessel's lines.  On the whole, I'm pleased with the result.

We now jump forward to the present build state.  Can you spot all the differences?  My focus has been on making the hulls weather tight as the build will be moving outside in the next few months.  Areas adjacent to, hardware plugging the hulls, have received the finished coats of paint before the hardware is installed and bedded with butyl tape.  Additional fitments will be made once the project moves outside.  Areas receiving these fitments will remain unfinished and primered until a future time.

The opening deck hatches feature an insect screen as well as a blind.  If a person were to sleep with their head forward, they could enjoy the night sky view as well as the in face hatch breeze.  

The shiny warts next to the hatches are also located aft.  The warts are solar powered ventilators that supply and exhaust the hull's internal air.  This is said to be an effective way to prevent mold and fungus growth.  The warts also feature a welcome small lamp to light up each cabin's dark ends.  I call them warts because the shiny stainless steel looks garish to me.  A brief examination found the optional stainless steel covering was just held on by small tabs bent over a white form and easly removable at a future date.  That should tone them down considerably and I may then know them better as ventilators rather than warts.

The main hatch tracks require standoffs to accommodate screws and the curved roof structure.  In the background is a standoff with screws securing it in position as the epoxy sets.  Each screw is working against a washer stack so that no screw pokes into the interior.  Much care was taken in this regard given the multitude of screws involved.

Highspots required some planning for smooth hatch operation.  The standoffs received a fiberglass top and epoxy fillets along both sides.  Once the sanding, repeated sanding and final paint coat was done, a new problem emerged.  When the full multitude of screws is installed in the hatch track, it induces a twist that binds hatch operation.  This earlier image is the same finished area re planned to remove the twist.  Curiously, this same correction was applied to the same area on the other hull.  May this geometric curiosity never rise to one that keeps me awake at night.

Intricate sanding and painting required between the inner and outer coaming.

The sliding hatches slip into a house to close the open end and "seal" against the hatch collar lip.  Note that the house has a curve matching the collar lip.

This image shows the progression from 3/4" stock to finished curved house segment.  A template is screwed to stock so a template outline can be traced onto the stock.  The template is removed so the stock can be rough cut outside the lines.  The template is reattached to the stock so a router bit can follow the template to create the finished shape.  

The house segments are glued together to form the house top and back.  I can't say the curving back added anything, but there it is.  These received the fiberglass treatment inside and out for weather proofing and strength.  The houses will be the primary securing point for locking the hatch.  A weep hole is incorporated into the houses should any water get past the collar lip.  The houses await modifications to receive hatch latches before installation.

After much resanding a semi finished result!  I had only enough of the light Grey antiskid material for one patch on each hull top.  A second wider antiskid patch coating will extend forward of the hatch standoffs where a person might gain footing closer to the roof edge.

I like the antiskid color against the off white paint.  I've never trusted my judgment on matters of selecting colors comfortable with each other, but I find this combination comfortable on the eyes.

I think the hatch and its house look good from the side, but ........

The aft view is ..... awkward.   I could do nothing and tell everyone it is a roll bar.  You may note the aft warts and the installed opening portlites featuring bug screens.

A possible solution is to reduce the visual height by painting a contrasting color.  In this image blue tape is applied to the hatch house top simulating a different color.  In practice the visual height is better shorter than shown here.  The arc of contrasting color house will echo that color applied to the crossbeam arched tops and the shear stringer sweep.  If a girl wants some action, it helps to emphasize the curves. 

Too Porty

September 2021 marks the forth year of this boat build project.  I've added a number of refinements that have extended the difficulties and time requirements.    Others may have built and launched a similar boat in less than this time span.  It is my hope to produce a finished product that is not a crude embarrassment.  The boat hulls are the most time consuming part of this build.  Both hulls are nearing completion and I've come to the most dreaded part of the build:

Fairing: The process of smoothing a vessel's surface to eliminate irregularities. 

Generally, fairing requires three or more applications of an epoxy filler compound to produce an acceptable surface. Hand sanding between each coat is required.  Sandpaper attached to a long flexible board averages out the surface by removing the high spots and revealing the low spots.   The image above shows the inverted port hull ready for another round of sanding.  It takes about three days to sand each side of a single hull.  This process uses massive amounts of epoxy that is later turned into sanding dust.  Sure, I may whine about all the sanding, but at times I find myself getting into the mindless tedious task.  I can look "forward" to repeating the process on the starboard hull.

With the hull faired, it was time to establish a waterline so that painting could commence.  The plans give dimensions down (it is up with the hull inverted) from the deck at the bow and stern to establish the waterline.  The hull is first leveled to assure it is not rotated to the right or left.  Leveled batter boards are then established at the prescribed distances from the bow and stern decks.  A fishing line is strung from one batter board to the other.  Weights at each fishing line end keep the line tight.  The line is moved along the batter boards to position the line near the hull as pencil marks are made along the hull length to define the waterline.  The line, batter board and pencil point are sighted in the same plane before each mark is made.

Masking tape follows the pencil marks to define the waterline.  The rudder is temporally clamped to the hull so that the waterline can be masked off.  Everything below the water line will receive an ablative bottom paint to prevent marine growth.  The ablative paint sluffs off with use and will require intermittent renewal.

Before I got too far along with painting, I remembered to install a fitting for the forestay (forward mast stay) bridal on the bow.  This fitting will be drill out to receive a U bolt that the bridal attaches to.

A drilling jig made it possible to drill the holes straight and parallel.  The holes were then re-drilled with incrementally larger drills so that the holes can later be filled with epoxy then drilled out again to the original size.  All holes in the boat are treated this way to prevent water from contacting the wood and promoting rot.

Areas below the waterline received two coats of a grey epoxy primer.  This coat was as rough as sandpaper and had to be hand sanded down before the three coats of black bottom paint was applied.  The bottom paint was less rough, but it may smooth out with use and I may or may not sand it as well.  Three coats of the off white (yellowish cast) topside paint was applied with wet sanding between coats.  I find that things go faster with wet sanding topside paint as the sandpaper will otherwise get clogged.  The wet sanding dust is immediately wiped off the boat as I find it very difficult to remove the sanding dust from my hands if allowed to dry.  Before applying the last paint coat over the sanded surface, a Scotch Brite was used to remove all the bright shiny areas in the hopes of producing a durable and satisfying result.

I'm contemplating painting the shear stringer (in primer white above) in a contrasting color.   I'm thinking of burgundy.  This might also be applied to portions of the crossbeams and other areas. 

At a point in the sanding, sanding and repeated sanding I've had to replenish my sandpaper supply.  Trips to the hardware store are usually an adventure.  A person is not allowed to peruse the hardware aisles and make those impulse buys.  Instead a person must convey, to a person behind a counter, the hardware item required before the item is presented.  In some hardware stores, the person behind the counter is a young woman.  Pleasingly, these women seem much more knowledgeable about hardware than I expect in young North American women.  Adding to the adventure are the different terms Belizeans use for hardware.  Sanding discs are called stick ons as an example. 

Knowable presenters on YouTube videos suggest using a finer grit sandpaper before applying the last paint coat.  Armed with this knowledge I announced to the young woman behind the counter that I required a packet of 280 grit sandpaper.  She checked with her computer and then said, "We have too porty".  "Too porty?", I queried.  Apparently, this did not convey my total bewilderment.  "Too porty", she repeated.  We went back and forth with too porty several times before a light came on and I realized she was saying 240.  She went off to fetch the too porty after I indicated it would be fine.  She returned with 220 grit sandpaper and indicated they were out of too porty.  I took the 220 grit home and used it as it is the grit recommended by the paint manufacture. 

At times progress has been delayed due to the lack of materials and the arrival of international goods.  I seek out little sub projects that must be accomplished at some point.  Above are five stainless steel items recently fabricated.  The smaller hook like item is a latch to secure the alcohol stove against the sloping hull side.  The remaining four items are bearing plates that rest under the bow and stern cleats.  The bearing plates prevent cleat forces from crushing the wooden decks and thereby loosening.  These parts were cut from a flat bar by a grinder.  Grinding, filing, sanding, drilling and polishing produced these finished parts for a future installation.  I hope I remember making them and where I put them!

Work on the starboard hull electrical system is complete to the extent that can be done until the boat is fully assembled.  Topside paint is also being applied to this hull in the areas receiving hatches and portlights.  This is so the hull may be made weather tight as the construction will move outdoors in a few months.

In late breaking news, the smoked cast acrylic sheets for the portlights has arrived.  I saved the plywood removed from the openings so they could be used as templates.   I've never worked with acrylic before and was very cautious while producing the first portlight.  Having some practice cutting the acrylic, the remaining portlights were quickly turned out.  It was just a matter of tracing the template on the acrylic protective paper sheet, rough cutting outside the line and then attaching the template to the sheet and running a router patterning bit around the perimeter against the template.

The portlights are not yet installed, but will be adhered with an adhesive used to secure windows in skyscrapers. 

It is unfortunate that the hull side is so close to the wall that a person can not stand back and view it from a distance.  The hulls have an upward sweeping shear that the portlights mirror on the bottom edges while the top edges are straight like the roof line.  This coupled with the black bottom paint and black portlights should look cool if not sinister.