Monday, June 30, 2014

June, 2014

Painting The Inside

After applying two coats of Interlux Epoxy PrimeKote 2-part primer, I lightly sanded and cleaned the hull as prescribed, and applied the first coat of white Interlux Perfection 2-part polyurethane high gloss topside paint.

I followed the recommended roll and tip technique using a West System foam roller and a badger brush.


About 48 hours later, I lightly sanded and cleaned the inside of the hull in preparation for the second coat. For the second coat, I added Interlux's Flattening Agent for 2-part polyurethanes.

Mixing 2-part paint with thinner and then with 2-part flattening agent requires different part ratios and a specific mixing sequence to obtain the desired result per Interlux's instructions. I created a spreadsheet to calculate the combined ratios to mix only the amount of paint I needed.

View of the hull after the second coat was applied.


Finishing The Deck Frame

In preparation for the deck, I had to build up the deck frames to ensure the top surface of the deck frame is leveled with the sheerline. This work included building up the king plank, the breasthook and the deck beams.

My mistake was not to interpret the drawings correctly when I fitted the deck beams, the breast hook and the king plank, although the drawings were clear. 




Western Red Cedar strips added over the deck beams... 
...and 30 mm x 4 mm marine plywood over the spaceframe tops.

Western Red Cedar added over the king plank and the breasthook, shaved and sanded.
View of the added Western Red Cedar over the main foredeck beam...

View of the added Western Red Cedar over the forward foredeck beam and king plank after shaving and sanding.

Next, I cut two 6 mm plywood pieces to fit between the jib cleat and the aft deck beam on the starboard side. I glued both pieces together with epoxy resin and colloidal silica. Then, I shaved the starboard plank angle and fitted the 12 mm plate with more epoxy resin and colloidal silica. The same process was followed on the port side.

This doubler is for the main and lower shroud sheaves.

I decided to add more curves to the deck to smooth our her lines around the aft deck beam where it intersects the king plank and where it turns around towards the jib cleat.

I cut a couple of 48" long x  30 mm wide strips of 4 mm thick plywood. I made the cut across the grain to facilitate the bending of the plywood around the desired turn radius. The width, from a point in the rear deck beam, was reduced to 25 mm at the king plank. One piece was enough to go around from the king plank to the aft deck beam and to then to the jib cleat.

For the rear, I cut a couple of 24" long x  20 mm wide strips of 4 mm thick plywood. I also made the cut across the grain for these to facilitate the bending of the plywood around the desired turn radius.

Next, I added Western Red Cedar reinforcements behind the plywood bends between the king plank and the aft deck beam. Also behind the bend between the aft deck beam and the stringers reinforcing the carlin. 
Likewise in the rear, behind the plywood bend between the stringer and the transom

The Deck

Varnish will cover the deck around the boat so I made sure to select a couple of 4 mm sheets of marine plywood with a pretty wood pattern to show off. This is the one I selected for the foredeck.

Firstly, I measured the distance between the aft end of the king post and the forward edge of the breasthook where the deck will end. I added 1 inch to that dimension and cut the plywood sheet across. Secondly, I centered the sheet of plywood along the king plank leaving half an inch extra aft and forwards so I can then plane it to shape after it has been glued in place.

Jeremy Deacon, fellow Merlin Rocket sailor and builder, recommends this procedure. This way not only does one have a slight margin for error but one gets a really good straight join when doing the gunwhales. Jeremy has also done several top-notch boat restorations. Thank you, Jeremy!

Once over the deck, I secured the foredeck with clamps and using a pencil I traced the outer edge of the gunwhale underneath. Then I moved the foredeck to a temporary work bench protected with poly to avoid damaging the face of the plywood that will be exposed. I traced parallel lines to the gunwhale lines, half an inch apart for cutting the foredeck with an extra margin for error.

Using a power jigsaw, I cut along the lines. Then I placed the foredeck back on the deck frames, centered and secured with small clamps. Next, I traced the curves  under the foredeck from the aft deck beam to the king plank. Later I added parallel line half an inch apart for error margin before cutting.

View of the new foredeck from above. I'll follow a similar deck pattern as done on Rob Holroyd's WICKED. Two triangular pieces left from cutting the foredeck will be squared off and used to cut the adjacent pieces to the foredeck that will go half way down over the doubler for the main and lower shroud sheaves.


Next, I cut the second 4' x 8' sheet of 4 mm marine plywood in half along its length, ending with two 2' x 8' pieces. One for each of the side decks.

Later, I clamped the two 2' x 8' pieces over the side deck and over the transom. 


For tracing the outer gunwhales on both side decks, I followed the same process as with the foredeck, then adding a parallel line about half an inch apart for error margin.

Same process with the inner carlin lines except some careful foot work and balancing inside the hull was needed to trace the pencil lines.


View of the foredeck, the side deck and the deck piece between the foredeck and the side deck that was made from the plywood triangular pieces left from cutting the foredeck.


Aft view of the side deck turning around towards and over the transom. A narrow 25mm plywood strip was cut and placed over the transom, connecting both side decks.



All deck pieces in place before epoxy coating and fitting.


Looks like she's already smiling and just waiting for makeup!

Saturday, May 31, 2014

May, 2014

Sanding The Inside 

Sanding is a tedious but necessary step. It's messy and it takes a long time to go through the entire surface. Every plank, rounded edge, filet and pass-through hole was sanded using 220 grit sanding paper, one section at a time.


I didn't like the way the single centerboard cap looked so I added another 6mm layer of marine plywood with rounded edges and 6mm shorter all around to give it a stepped look.


I also fitted the hardwood floor stringers to provide surface for the jib sheet tracks. The stringers are 20" long, 1-1/2" tall and 1" wide. 

View of the two step centerboard cap and the jib sheet track stringers.


Another view of the two step centerboard cap and the jib sheet track stringers.


It took a long time to sand the inside but the finish will reflect the effort and it will be worth it.

Priming The Inside


Next, I applied the first coat of Interlux two-part PrimeKote primer. Priming the inside is more demanding than the outside. For one, there are many inside angles to cover. 








Filleting the joints with the round edge end of the filleting tool definitely was a big help as I applied the primer with a 1/4" radius roller. 




I also used a 1-1/2" badger badge to cover around the floor strengtheners the tight angles.



Before applying the second coat of Interlux PrimeKote primer I fitted the two cleat platforms for the main sheet hoop controls over the thwart. Made from the same hardwood stock as the one I used for the crew floor stringers, I  glued the cleats to the thwart using epoxy resin mixed with with colloidal silica.

The precise location for the cleats and all other interior parts can be found in the Interior Construction and Layout drawing from designer Keith Callaghan.


Lastly, I fitted a hardwood mounting block for the mainsheet swivel jammer.


Next, I applied the second coat of Interlux PrimeKote primer. It was just as challenging as the first one.  


Aft view after priming.


Having applied only the first coat of primer to the foils, I proceeded to apply the second coat of primer to the rudder...

...and to the centerboard.


Thank you for visiting!

Fair winds and happy sailing!



Wednesday, April 30, 2014

April, 2014

The Floor Strengtheners... Continued

Last month, I managed to cut out all of the floor strengtheners. This month I started by fitting the floor strengtheners with a good dose of epoxy resin mixed with colloidal silica. To ensure good bonding and proper fitting, I used two Texas limestone rocks to hold the floor strengtheners down against the planks.
  

The floor strengtheners between the main space frame and the bow tanks have the most curvature and require the most downward pressure to secure them against the planks. The chopped rocks proved very useful although I was extremely careful not to drop them and damage the hull. 

Three coats of epoxy resin were applied to the floor strengtheners after fitting, with light sanding between coats.  

Next, I cut the centerboard 'tail' that finishes the top curvature of the centerboard past the aft space frame. Made of hardwood, the 'tail' extends about 12" from the aft space frame. To plot the curvature, I used an aluminum ruler against the centerboard to project and trace the curvature down the tail.




Then, using a band saw, I cut the piece. It was later fitted onto the hog and against the aft space frame using epoxy glue.


Two stringers are fitted between planks #3 and #4 in the section between the the main space frame and the aft space frame. One stringer on the starboard side, one on the port side. My stringers are approximately 24" long by 2.5" high and 0.5" thick. For the stringers, I used re-sawed hardwood left over from the king plank.
To cut the curvature of the plank along the bottom edge of the stringer, I placed the stock over the plank and next to the strengthener. Using a pencil, I traced the curvature of the strengthener (which is parallel to the plank) against the stock. Then, using the band saw, I cut the curve along the bottom edge of the stringer to obtain a perfect fit.


The Hazardous Zero-9 drawings call for two 25mm x 25mm hardwood pieces to be fitted at each side of the king plank, from the main deck frame intersection to its aft end. I cut the hardwood stock in two pieces for each side. One to fit from the main deck frame to the aft deck frame, the other to fit from the aft deck frame to the aft end.


Next, I fitted the platforms for the control line cleats on the thwart. The platforms are made of marine plywood and are approximately 12mm x 40mm x 12" in size. These the ones specified in the Hazardous Zero-9 drawings. Other arrangements can be made to suit the specific needs of a crew.

The starboard side platform for the control line cleats at the thwart.


The port side platform for the control line cleats at the thwart.


Before getting further ahead, I caught up with sanding and filleting the underside of the thwart and the cleats. For the filleting behind the cleats I used an ice cream stick with a rounded edge. If you don't have a stick handy, it is a great excuse to get an ice cream!

Using epoxy resin with colloidal silica, I fitted the two floor stringers I cut out earlier. The stringers are approximately 24" x 2.5" x 0.5"

I then fitted two floor platforms for the main sheet control hoop. One on the starboard side and one on the port side.





The platforms are approximately 4" x 2.5" x 0.5" cut from the same hardwood stock.

I also cut two cleat platforms for the main sheet hoop controls over the thwart. I will fit these later once I get the hoop stock and drill the holes on the thwart. 



And finally, I cut the centerboard cap that runs from the thwart, over the aft space frame, down to the end of the centerboard tail.

The cap in my boat is made of 6mm marine plywood. It is 90mm wide at the thwart and 50mm wide at the end.




The end of the centerboard cap was rounded to a 25mm radius and the edges were subsequently rounded off with a 0.25" quarter round carbide router bit prior to fitting.

I used 4 screws with temporary wood blocks to secure the cap flat and tight against the centerboard case during epoxy bonding.

Here she stands, almost ready for interior finish. Still need to fit the floor stringers to provide surface for the jib sheet tracks, and a couple other details I'll reveal next month.

Thank you for visiting my blog! Comments are welcome.

Fair winds and happy sailing!




Monday, March 31, 2014

March, 2014

The King Plank


The king plank in the Hazardous Zero-9 is made of hardwood stock and measures approximately 25mm x 50mm x 260mm. It is fitted in a cutout over the deck beams and is partially rebated over the breasthook.

I used a router to cut the rabbet in the breasthook. Prior to gluing the king plank to the beams and the breasthook, I fitted the king posts.





The King Posts

The king posts are made of hardwood stock and measure approximately 30mm x 30mm. The edges were rounded off with the same router bit I used to round off the plank edges.


The king posts stand in a clever compartment formed by the sides of the centerboard case at the front, the hog at the bottom and the aft face of the bow tank bulkheads. The king posts are partially rebated under the king plank.



I used a router to cut out two square slots, one for each king post.


View of the king plank from and the king posts from the transom before gluing the king posts.











A side view of the setup after gluing the king posts.












A hardwood wedge tightens up the fit of the king posts in the pocket. I rounded off the top of the wedge a bit to disperse any water.




The Aft Deck Beam

The aft deck beam is made of western red cedar. It runs from the king plank (partially rebated) to each of the top planks, parallel on both sides to the shroud knee and the bulkhead.




The top of the aft deck beam is also arched and aligned to the top curvature of the main and forward foredeck beams. I used a long aluminum ruler to project the top curvature of the foredeck beams back to the aft deck beam.


Starboard side aft beam

Port side aft beam.


The Side Deck Frame

The side decks have pine stringers to reinforce the carlins. There is an upper and lower stringer. The upper stringer runs parallel to the sheerline, from the main foredeck, around the space frames to the transom. The lower stringer runs from the aft deck beam, around the space frames to the transom.

Using my band saw, I re-sawed 8' long pine stock to make 10 pieces approximately 9mm x 18mm.



Then, I re-assembled my scarfing jig and proceeded to scarf the ends of each piece.

I mixed epoxy resin with colloidal silica and glued the scarf joints together. The next day, I had 5 reinforcement stringers approximately 16' long.


Here is a photograph I took while bending the stock to test its flexibility prior to gluing it with epoxy. Notice the stringer is fully rebated to the main fore deck beam and the aft deck beam. The excess forwards of the main fore deck beam is simply removed afterwards with a Japanese saw or similar tool.
Another view of the stringer fully rebated to the main fore deck beam and the aft deck beam.


A view of the upper stringer as it curves towards the transom.

Both stringers clamped tightly as the epoxy glue dries.
The lower stringer runs from the aft deck beam  to about half way between the aft space frame and the transom. Precise measurements are available in the Hazardous Zero-9 Layout and Side deck drawings provided by designer Keith Callaghan

I also added a 20mm x 20mm stringer along the top edge of the transom by laminating two 10mm x 20mm pieces cut to the required length.



The Floor Strengtheners

The floor strengtheners are made of 4mm marine plywood finished with rounded edges and corners. I'm fitting 4 (2 on each side of the hog) floor strengtheners between the transom and the aft space frame, 8 (4 on each side of the hull) floor strengtheners between the aft space frame and the main frame, and 8 (4 on each side of the hull) floor strengtheners between the main space frame and the bulkhead. Same configuration as Wicked, MR3708.

The dimensions vary at each plank but are mirror images between port side and starboard floor strengtheners.

In this photograph, I've cut and laid all of the floor strengtheners at their location. I can see already that fitting them onto the hull with epoxy glue is going to be very interesting in some places.


Thank you for visiting. Fair winds and happy sailing!