FLYING RAT PROJECT

The 2002 World Championships provided a great benchmark for comparing boats, spars, sails and of course sailing technique. Once again the Aussies showed us the way. Glenn Ashby's performance was nothing less than remarkable. Glenn excelled throughout the varied conditions (5-20 kt.).

The weapon of choice for the 5 of the top 6 finishers was the Flyer. Many of the top sailors in the class have gravitated to this design due to its success in the previous three World Championships. Other competitive designs sailing were the Melvin Waterat, the Boyer Mk 5, the Marstrom and the Boyer Mk 4.

I had been tempted to go with the flow and sail a Flyer at the Worlds but I had a lot of time in my Waterat and it was setup exactly to suit my style of sailing. My speed at the worlds was quite good, especially in the 5-10 knot range and at the top end in 17-20 knot range.

After analyzing the results and on the water observations, I determined that if I could improve my existing boat just a little bit I'd be very close to Flyer performance in most conditions. The big question was how to improve this boat.

One of the most noticeable differences in the Waterat and the Flyer is the height of the bows. The lower windage bows of the Flyer are definitely a plus. The other noticeable difference between the Flyer and the Waterat was the under water shape of the bows from the main beam forward. The Flyer here is basically "U" shaped while the Waterat is "V" shaped. The Flyer shape allows for easier turns and less pitching.

I decided I liked the back half of my Waterat but wanted to change the bows to be more "Flyeresque". My first thoughts were to modify the existing bows by a series of pie cuts, tucks, adding etc. and then fairing the re-shaped bows. While talking with Andrew Gaynor (USA 133), he jokingly suggested to just cut the bows off and put on new ones kinds like "Prada" was doing on a regular basis in Auckland. I thought about it for a while and decided that this was "not a bad idea". The next step was to bounce the idea off Pete Melvin. Pete said he would take a look at the existing design to see if it made sense. Pete ran a bunch of numbers and proposed a new bow design that started 3" in front of the main beam. He did ask me "Why not do the whole boat?” The problem was I did not have time to make a whole new boat. I wanted to sail in the Tradewinds and A Cat "Olympic" Key Largo Regattas. It was already mid October and I needed the boat on the trailer ready to head South just after New Years.

The challenge was to make a set of female molds that would produce a set of parts (bows) that would exactly match the existing hulls just in front of the main beam. This is where computers, DFX files, and CNC cutters make a job like this possible. Pete sent the lines files to Henry Elliot (C Class "Cogito" builder) who fired up his CNC router and cut the female molds. To reduce time and cost Henry chose dock Styrofoam as the mold material. After the shapes were cut, Henry covered the Styrofoam with three layers of 4 oz. Fiberglass cloth. We then sprayed the molds with Duratec and wet sanded them to 400 grit. We then Freekoted and waxed the molds. Instead of gel coat we sprayed Awlgrip 545 epoxy primer in the molds and let it dry overnight. Prior to lamination we scotchbrited the 545 and wiped it clean. The laminate used (starting from the outside skin) was 4 oz. glass cloth, 6 oz. carbon cloth, ¼" Nomex honeycomb and 6 oz. carbon cloth on the inside. We chose Gougeon Proset (laminating) epoxy resin. The entire laminate and core was put in the molds in one shot and then vacuum bagged. In the molding process we created a centerline flange in each half to have a good gluing surface. Once the bow halves were molded, we glued the two halves together to make a complete bow section. The excess glue was cleaned up on the seam and then we were ready to attach the bow to the old half of the hull. We put a 4" wide rebate (about .030 thick) in the area where the new bows joined the old hull. The core in the original hull is 3/8" Nomex honeycomb. The joining method ended up very simple. We dug out the core of the old hulls to a depth of about 1 ¼" but were careful to leave the inner and outer skins in tact. Since the new bows had the rebate and a ¼" core, the bows were inserted into the 1 ¼" deep gap with lots of thickened epoxy adhesive.

We set up a rigid fixture to hold to two halves at the hulls in exact alignment (a lot going on here) while they were being bonded together.

Once the bows were glued on, we taped the seam with a 4" band of carbon around the entire joint and then faired the area.

The next step was to "beam-up" the hulls. I had decided to get rid of the previous bolt on method (OK but it did leak a bit and would require a frequent tightness check). I made the decision to glue the beams in place and over wrap the beam/ hull joint. This creates an incredibly stiff connection. The bad news was the boat would no longer be able to winter in my basement (door width only 7"). To improve water flow from the bow the over the beam we fashioned a "ramp" to fair the hull/beam joint. This ramp was foam covered with one layer of carbon cloth.

The final modification was install "rails" to the hull to make the boat max width for trapezing. Again we used shaped foam covered with one layer of carbon cloth.

The next step was sending the boat off to the paint shop. We used white Awl grip 545 Epoxy primer and wet sanded the hulls to 400 (leaving a semi gloss finish).

After paint I installed a new bright blue Kinder tramp and reinstalled all the hardware. Wow the boat looked brand new!

It was now time to head off to Key Largo to try out the "Flying Rat" for the first time. I was able to tune up with Mark Sellnau the day before the Tradewinds. Mark has a Waterat virtually identical to my boat (before the modification). In the lighter wind range our speed was very similar both upwind and down...So far so good...at least it wasn't slower. As the wind increased to the 14 knot I had a slight speed advantage... maybe due to less weather hull windage?? The other thing that was quite noticeable was the ease of turning the boat. This was most evident when making the turn at the bottom mark.

Now it was race time at the Tradewinds. Weather was nasty...cold... with a frigid 18-20 breeze kicking up a nice shop. These were great conditions to see if this modification was worth it. Good news...Three firsts... I am happy, the boat preformed well on all points of sail. Lower windage, easier turning, and less pitching all made small improvements around the course.