February, 2014

The Keel Band

The Merlin Rocket Class Rule 4(j)(i) states that " A KEELBAND of metal or plastic and of depth not less than 2mm and not exceeding 7mm shall run the whole length of the hull."

Looking back, I should have completed this step before turning the hull over the first time. I guess I was too excited to get it off the building frames. I also would have made the keel band with epoxy resin. As it turned out, I fitted brass keel bands.

Sourcing the brass keel bands in the US was a bit of a problem. Online search didn't return the results I was hoping for. There is very little information about this product and of the few websites that offer it, most don't have it in stock. My first try with one particular online vendor I won't be doing business with again, was a disaster. They took my order and reeled me in for 3 weeks with a lot of promises but no results. Finally I cancelled my order.

Then I found out that Jamestown Distributors had the brass keel bands I needed in stock. I had ordered fiberglass cloth and carbon fiber cloth from them in the past and had excellent results so I knew they would deliver. Over the phone they helped me consolidate the shipment and saved me money. The shipment of four 6 ft pieces arrived on time, as promised, and the tubing used for packaging was very strong to prevent any kind of damage.

First, I laid out the brass keel bands over the keel and marked the dimension from the transom to the centerboard slot. Then I measured the 2 centerboard slot pieces that also hold the slot gasket. For the stem, I used a keel band piece left over from a previous cut (~1.2m.) and bent it at the intersection of the stem and the keel. The last piece I measured from the end of the stem piece to the forward edge of the centerboard slot.

View of the brass keel band bend at the intersection of the stem and the keel. I used a rounded wooden edge to bend the brass keel band against, and a wooden mallet to finish the contour around the stem and the keel.   

I proceeded to drill the holes for the wood screws. I spaced the holes every 4" for the centerboard slot keel bands, and every 6" elsewhere unless otherwise necessary.

On the work bench, I drilled the holes first. Then, using a larger drill bit, I widened the top opening to conceal the head of the oval round brass screw. 

View of the keel band at the bow,where it butts to the next keel section going back towards the forward edge of the centerboard slot.

I used the blue tape to hold the keel band in place. Next, I drilled a pilot hole in the keel to facilitate the entrance of the screw without splitting the stock. Last I manually screwed the keel band to the keel.

Next, I used blue tape to cover and protect the brass keel bands before turning the hull over.

Thanks to my good neighbor Danny, I was able to turn the hull over (finally Julio! I know,right?). After turning her over, I disassembled and removed my loyal and multi-functional jig and placed the hull over two padded moving dollies that now allow me to move her with ease in any direction.

The Jib Cleat Brackets

The Hazardous Zero-9 Merlin Rocket has two 12mm jib cleat brackets located at +2036. These brackets, one each at port and starboard, will hold a cleat and a cheek block.

After finding the bracket's starboard location, I used my angle finder to determine the beveling angle to fit the bracket against the hull.  

Then, I tilted the band saw table to match the desired angle and beveled the landing of the bracket accordingly.

Sometimes, the simple things take the longest.  Fitting the jib cleat bracket, for example. It is a small piece so it should be easy to fit. Right? Well, I had to find  a solution other than applying epoxy, holding it by hand and watch it cure (not an option). So here it is. Before any epoxy is mixed, a dry run is my way of actually finding issues saving time, materials and my hair.

I applied the same process on the port side.

The Main Thwart

The main thwart is fitted to the main space frame, the centerboard case and to both #6 planks, where the landing is beveled. I used my angle finder to determine the landing bevel required for both ends at the planks.

I projected the plank landing angle at both sides of the thwart's ends and scored a line across to determine the inner edge of the bevel.

The main thwart is not exactly an easy piece to work on a band saw so I decided to use my hand plane instead to cut the bevel.

Later I found a small obstruction on both ends. The fillet on the main space frame was in the way of a perfect fit. So I carefully removed the fillet section away and the thwart was able to fit perfectly.

Nice and tight fit on starboard but it required a weight to hold it down flat against the plank during bonding. I used two hydraulic bottle jacks, one of each end. 

Similar situation on the port side. Ready for epoxy bonding.

Once I made sure the thwart was going to fit correctly, I made a mix of West System epoxy resin, West System 205 hardener and colloidal silica and fitted the thwart.  

The Bow Tank Tops

Before fitting the bow tank tops, I cut the openings for a couple of deck plates that will be used for inspection and maintenance.

Using the actual deck plate as a template, I score its location on the bow tank top. Then I drilled a pilot hole at the center of the circle and through both bow tank tops which I had laid perfectly one on top of the other. This way I had the center of the opening at the same place on both bow tank tops. Using my compass with a scoring tip, I scored the circle of the other  

Then, using the plunge router, I cut out the hole.

Nice and round hole ready to receive the deck plate.

The deck plate will be fitted later after the finish is applied.

Once the deck plates were cut, I fitted the bow tank tops with a mix of West System epoxy resin, West System 205 hardener and colloidal silica.

A day later, I applied an epoxy fillet around the thwart and the bow tank covers, as needed.

The Foredeck Beams & The Breasthook

There are two foredeck beams in the Hazardous Zero-9. Both are made of 6mm marine plywood and have a 6mm plywood doublers on the aft face for reinforcement of the king plank opening.

The main foredeck beam is fitted at +1130 and the forward foredeck beam is fitted at +750. I used the same technique applied to the fitting of the jib cleat bracket. While the foredeck beams were cut at the mill with a CNC router it was still required to bevel the ends to their proper landing angle against the hull planks.

The breasthook is made of solid timber stock and is designed to take forestay anchorage. Its center is at +220. Easy to cut, bevel and fit, given its location. I'm afraid I didn't take a closeup photo. I'll take one it when I fit the king plank.

Using the angle finder to bevel the landing at planks #8, and later delicately holding the ends while bonding to the planks, I fitted both foredeck beams with a bit of epoxy.  

I then fitted the doublers and also added a western red cedar reinforcement beam under the foredeck beams to add rigidity.

I then applied an epoxy fillet around the foredeck beams and the breasthook, as needed.

The Transom Knee

The transom knee is made of 12mm marine plywood and is fitted at the intersection of the hog and the transom. The transom knee was also part of the CNC kit.

Having all these components as part of the CNC kit allowed me to encapsulate them in epoxy ahead of time and pull them off the shelf as needed.

Before fitting the transom knee I added a 12mm x 90mm marine plywood reinforcement piece to the transom. Finally, I fitted the transom knee with a good amount of epoxy resin and colloidal silica mix. I then applied an epoxy fillet around the transom knee and the transom reinforcement piece.

The Mast

My carbon mast finally arrived! The custom mast for the Hazardous Zero-9 was built to Keith Callaghan's specifications by FORTE Carbon Fiber Products in Ledyard Connecticut, USA. 

Clint Rand, Director of Operations at FORTE, was all too familiar with the Merlin Rocket mast. After all, Clint built two carbon masts for John Keeling who built the first Hazardous in the US. This was a key factor in making my decision. I love the fact that Clint was willing to take a small custom order. FORTE does big composite projects. Thank you John for your recommendation! 

I started to work with Clint last year going over the specifications and requirements. We went back and forth with the details and his recommendations. I finally placed the order at the end of last year. FORTE fitted the carbon sail track and also provided the spreader bracket and spreader tips. Once completed, the mast was encased in a heavy duty tube with pinewood end caps and shipped it to my home, some 1,850 miles away.

Fair winds and warm weather to all!