Category Archives: Carbon Fiber

Repairing a Hockey Stick

By Captain James R. Watson

Ice hockey sticks are exposed to cold temperatures plus high shock forces from contact with the puck as well as with the ice and skates. Hockey sticks can be wood/fiberglass laminates or composites of carbon fiber or aramid. The stick blades often chip and split with use and have to be repaired (or else replaced at $50–$150 each). A customer who repairs and maintains hockey sticks for a local team had been using a conventional epoxy for repairs and found that it often chipped under such use. Continue reading

The Flying Tigers rocket team with their finished 8' 4" rocket. From bottom left, clockwise: James Roesner, Richard Lester, Brad Parker, Kyle Smith and Brett Cockerill.

A Mile High in Huntsville

Building a competitive model rocket

By Brad Parker

The 2006 NASA Student Launch Initiative (SLI) began for the Flying Tigers, a competitive model rocket club at Caro High School, Michigan, when we accepted the 13th place award in the 2005 Team America Rocketry Challenge at The Plains, Virginia. At that point, we had no idea what we were getting ourselves into. Approximately six months, and thousands of dollars and work hours later, we enjoyed the products of our labor with a perfect flight into the blue Tennessee sky. Continue reading

Building a Masthead Fitting

by Captain James R. Watson

Here’s another use of the lost foam method to produce a custom part with a molded interior cavity. In this case, the part was a mast head fitting to hold an internal sheave and provide a route for the halyard to pass. This method can be adapted to a variety of other applications, as demonstrated in Fabricating an Airscoop. Continue reading

Comparing Cost and Weight of Flat Panels

By Jeff Wright

We compared the cost and weight of four panel types:

• Epoxy coated XL Plywood Boat Panel

• Epoxy coated Okoume Marine Plywood

• Epoxy/fiberglass/balsa cored composite

• Epoxy/fiberglass/core cell foam composite       

Many WEST SYSTEM® customers appreciate the benefits of cored composite construction. They understand that it creates a part that is lightweight, strong, and stiff. We often receive calls from these customers inquiring about using a composite panel when building or repairing something that would normally be made of plywood. Such projects may include a Continue reading

The Importance of Stiffness in Small Boat Performance

by Meade Gougeon

Epoxyworks 21

Cover Photo: The SWIFT SOLO is a single-handed skiff built by Bram Dally. Stiff, durable hulls are crucial to skiff speed.

One of the little known or understood characteristics of modern fiber- reinforced plastic composites is the loss of some initial stiffness capability after repeated cyclic loading. Loss of stiffness can be significant enough to cause a noticeable effect on performance, depending upon laminate makeup and degree of cyclic loading.

Loss of initial stiffness after repeated cyclic loading was first noticed in several highly competitive racing dinghy classes where older boats that had been sailed hard for Continue reading

SCHEHERAZADE

By Tom Pawlak

On a break from the Maine Boatbuilders Show in March, we visited Hodgdon Yachts, Inc. and found significant progress on their latest build, a 155′ Bruce King designed wood/epoxy ketch, named Scheherazade. This is Hodgdon Yachts’ largest wood/epoxy vessel to date. The project is roughly 60% larger than Antonisa, the 124′ sailing yacht they launched last year.

Scheherazade is being built in Hodgdon’s new 20,000 square foot facility located at the water’s edge in East Boothbay, Maine. A project this size would not have been possible in

Scheherazade under construction in October, 2000. The new Hogdon Yacht facility has a 164′ x 50′ center bay, large enough to accomodate roll overs of large vessels with a 400 ton overhead crane. 100′ x 20′ wings on each side are three levels high.

Continue reading

Modern Decked Sailing Canoe

Modern Decked Sailing Canoes

By Hugh Horton

Using epoxy with wood and modern high modulus fibers,the homebuilder can create light and strong evolutions of the sailing canoes designed by the Scot, John McGregor,in the 1860’s. Modern decked sailing canoes are simple, efficient, solo craft which are equally proficient under sail or double-bladed paddle. Puffin and Serendipity,for example, are 15′ long with a 34″ beam. Their unrigged weight is 45 lb; fully rigged weight is under 70 lb, including Continue reading

Building Components with Kevlar Braid

By Hugh Horton

Braided Kevlar®, or composites with Kevlar and carbon braid, are used for joints and many components of my sailing canoes. These include the hull/deck joint, cockpit coaming and spray deck rims, the leeboard bracket and retaining pin, the attachment of the mast step to the hull, the gunter’s yard heel fitting, and the Continue reading

Evolving the Sailing Canoe Rig for Cruising

 

By Meade Gougeon

The original sailing rigs on both Serendipity and Puffin are Hugh Horton’s sophisticated version of the old, but efficient sliding gunter rig (Figure 1). Hugh had put a lot of thought into sailing rigs for canoes and had chosen the gunter because it best fit several needs that he considered mandatory for a cruising canoe.

First and foremost for safety reasons, any rig for a sailing canoe has to be quickly removable and easily stowed inside the hull while at sea. This means that no part of the rig can be longer than 7′. The rig also has to be very light and reefable because of the limited righting moment available. This is a gentlemen’s boat, where we stay comfortably positioned in the cockpit on a cushy adjustable seat, rather than hike out over the side as one does with normal dinghies. We do “ooch” our adjustable chair up to the high side and lean over to weather, which gives us enough righting moment to be surprisingly effective, but with the sailing canoe, weather work must be done with finesse rather than brute force.

Knowing that I had done a lot of playing with sailing rigs over the years in both multihulls and iceboats, Hugh challenged me to come up with a better rig than the gunter while he was building Serendipity. I declined, being just smart enough to know that without some time in the cockpit, it was highly unlikely that I was going to improve on the overall effectiveness of his beautiful, lightweight (8lb all up) cedar/carbon gunter rig.

After taking delivery of Serendipity, I sailed her continuously for over a month before my mind really began to turn on new possibilities for rig configurations. First, it appeared that the gunter rig had several areas that could be improved upon. It was apparent that the gunter rig was somewhat under-canvassed at 34 sq ft of sail; in winds up to 10 to 12 mph, more sail area could be carried to make her an even more spectacular light air performer. Second, while not bad aerodynamically, the gunter is not in the same league as modern batten supported high roach rigs, such as we see in catamarans and windsurfers. And third, the gunter had only one reef point which effectively reduced the sail area in half. This, together with the time and difficulty of putting in the single reef, meant that I was spending a lot of the time with either too much sail up or not enough when reefed. The obvious solution was more sail area with numerous reef points providing more choices of sail area. This could contribute to both the overall efficiency and safety of the sailing canoe.

How to do this without unnecessarily complicating the rig was the challenge. Fortunately, I didn’t have to face this challenge alone. As the evolution of the new rig progressed, I slowly gathered together a team that was very helpful in its development. The first breakthrough centered around a novel idea from Stewart Hopkins, of Dabbler Sails (our gunter rig sailmaker), who suggested the use of a snap on equivalent of the old mast hoop approach. Using a 35¢, 1½” I.D. PVC pipe coupler, we cut away about 40° of its diameter so that it will “snap on” over a 1½” diameter mast with a little push. Once in place, it resists all sail forces and the PVC coupler easily slides up and down the mast for easy hoisting and lowering. Most important, the sail, which is attached to these couplers, is easily and quickly removable from the mast with a firm pull at each coupler (Figure 2).

This was the key to having a method of quickly dismantling the rig so that it could be stowed away. A secondary benefit was that the couplers allowed the sail to sag off to the leeward side of the round mast, providing a good aerodynamic entry on the power producing leeward side of the sail, which we further augmented by allowing the mast to rotate from tack to tack, as does the gunter.

The next problem was the 12′ mast that needed to be broken down into smaller lengths for storage in the hull. The weight of the mast is critical, as is its windage if left standing when the sail is fully reefed. Hugh Horton felt strongly that we needed a three-piece mast where we could leave out a center section so it could be reduced from 12′ to 8′ in length, such as happens with the gunter reefed mast. The problem with joints is that no matter how well done, they increase weight and degrade stiffness and strength potential. Enter Paul Beiker, boat designer and engineer, with extensive experience with the use of carbon fiber in masts, poles, and booms for International 14 dinghies. We gave him the challenge of developing a three-piece mast that would meet our needs (Figure 3). Within a month, he delivered parts for the perfect mast, plenty stiff, strong and weighing only 4.5 lb (2.8 lb when reefed).

We now only needed to perfect the sail itself and develop a quick reefing system with the goal of being able to reef and unreef at sea, which was difficult to do with the gunter. I have always been impressed with wishbone supported rigs, which function similarly to the sprit on a gunter, but allow the sail to be effective on both tacks. In addition, attaching the forward end of the wishbone to one of the couplers allowed the wishbone structure to become the key ingredient in what has become a marvelously simple and efficient reefing system (Figure 4).

The luff of the sail is designed with what we call “tack” grommets beginning with the traditional “tack” position at the bottom, with others positioned every 6″ all the way up to the top batten. Using a fastpin in a fixed tack position on the mast, you can lower the sail to a variety of potential reef positions and reinsert the tack pin. The two-part Technora™ (read low stretch) halyard is then tightened to provide adequate luff tension and avoid the complexity of a downhaul (Figure 5).

The clew end of the wishbone is designed so that three separate color-coded lines are rigged, each with a separate function (Figure 6). The first goes through the clew and allows for adjustment of the draft of the sail. The next two are rove through the first and second reef points. To reef, one only need to release the clew line from a jam cleat, then grab one of the reef lines, pull it tight, and place it in the same jam cleat. To unreef is the same process in reverse.

With this basic reefing strategy in place, we began to develop the sail size, shape, and number of reef positions. Over 6 months, we built three different sails with modifications in-between. Each step forward was taken only after a long consideration to prove or disprove various ideas and theories. In this process, Hugh Horton and our sailmaker Stewart Hopkins were valuable allies. Stewart’s long experience in this field saved us from going down blind alleys or reinventing the wheel. This, together with sea trials against Hugh in Puffin to measure progress, allowed us to accomplish in 6 months, at a fraction of the cost, what has taken years to accomplish with our multihull and iceboat rigs in the past.

The final rig in this progression has some significant advantages (Figure 7). First, we have developed a simple and efficient reefing system that provides 5 sail plans ranging from 40.4 sq ft to 14.1 sq ft. The “maxi reef” allows for sailing this small boat in winds up to 30 mph. Second, with the use of a large headboard, full battens and rotating mast, the rig is dramatically efficient. This is seen in all wind conditions and on all points of sail, but the great joy of this new rig occurs when going to weather in lighter winds and tacking within 80° at speeds up to 4.5 knots.

So, is this the ultimate rig for one of these boats? Not on your life. The evolution continues with Hugh Horton presently developing a super gunter rig with Stewart Hopkins that will combine the best from both the past and the future. Then, of course, I already have another idea that I would like to try out soon.