Boat Building Basics
Before the advent of fiberglass as one of the materials used in building boats, materials such as steel and wood were used. These materials had to be assembled in parts and pieces to create a structure that was then sheathed with a hull. But with the advent of fiberglass construction techniques, the main parts of a sailboat such as the hull, liner, deck, and other large parts such as the consoles can be easily constructed using fiberglass.
Structural reinforcements such as bulkheads and stringers can be constructed separately and then incorporated into the main parts of the boat. Other parts such as the inboard engine, water, and fuel tanks can be mounted when the hull is still open. The same applies to other things such as wiring and plumbing; they should be done when the hull is still exposed.
Other major components of the sailboat can then be assembled. In most cases, the deck will be lifted using a crane and lowered into the hull before the two components are fitted accordingly. Once the major sailboat components are assembled, interior fittings such as steering wheels and seats can be added before the finishing touches and details are done.
It's also important to note that many modern sailboats are designed using what's known as the "shoe-box" joint, which revolves around the deck and the hull having mating flanges. This means that they should overlap one another before mechanical fasteners such as through-bolts and screws are used to secure them together. Other methods such as the use of sealants and chemical bonding agents such as 3M 5200 and methyl methacrylate are highly recommended. These agents are superb in making the sailboat and its joints watertight. You can also use fiberglass to secure the perimeter around the hull and the deck joints.
Changes in the Boat Building Process
One of the most important changes in boat building was the shift from wood to the use of fiberglass. Again, the move from normal fiberglass to the use of exotic materials and techniques has also been a good addition. But even with all these, the concept of building a sailboat remains the same.
Most advances also revolve around making sailboats stronger, lighter, and faster, especially when it comes to offshore racing sailboats. As such, many modern sailboats have followed the concept used in the aircraft manufacturing industry where the main concern is to make aircrafts lightweight and strong.
There have also been advancements in the way sailboat materials are designed and brought together to make what will finally become a sailboat. Here are some techniques that are used to maximize strength while minimizing weight.
Vacuum Infusion - This is the process of incorporating plastic film and a vacuum to achieve the perfect resin-to-glass ratio. Using a set of resin feeding lines, the resin can be drawn the cloth to offer exact measurements of these materials and how pressure can be applied across a large area so that larger parts of the sailboat can be laid up.
Vacuum Bagging - This method revolves around open molding layup whereby a wet laminate is enclosed in a plastic film and the vacuum is used to remove the excessive resin. You have to keep in mind that resin doesn't add any strength to your sailboat and that's why using fiberglass in constructing sailboats is the in-thing although you'll have to contend with additional weight. This process is of great importance as it helps in reducing the sailboat's eventual weight without interfering with its strength or efficiency.
Cold Molding - While a huge majority of modern sailboats are manufactured using the above-described methods, there is an alternative method, which is often used in manufacturing large yachts or when the price is not a major factor. Most of these yachts or large cargo ships use metal or steel hulls and a technique known as cold molding is often used. It involves crafting the structure of the boat from wood before it is encapsulated or layered with epoxy resin and hand-laid fiberglass.
The Development of Sailboat Design
When it comes to building a sailboat, the most important step of the entire cycle is the design process. The design process will, of course, determine the use of the boat and how it looks. Needless to say, boat design has over centuries not just because of the need to improve how sailing is done but also because of various global events as well as environmental regulations.
Today's boat design process has truly come a long way since the days when ancient Egypt used reed boats and ancient Greek used triremes. But even with that, the maritime industry has experienced continuous improvement in the way boats are designed thanks to increased innovation and technology and this trend is expected to naturally continue going into the future.
Here is a brief look at how boat design has evolved since the early days.
The Evolutions of Boat Designs from the Early Days
In ancient seafaring, boat design was mainly categorized as warship design or cargo design. As such, cargo ships were bulkier, slower, and were designed to store cargo in large quantities. On the contrary, warships were light, faster, and had enough areas to accommodate thousands of soldiers.
Another important aspect that was considered when designing boats in ancient times was sailing techniques. This was long before the invention of machinery so many sailors had to rely on the wind and weather conditions that were dominant in a particular region and this informed some unique features that were incorporated in boat design.
As humans ventured deeper and deeper into the uncharted ocean, various significant technical developments were included in boat designing. They included:
- The types of sails used
- The hull and stern
- The use of multiple masts
- Various methods of rigging
Other Factors that Influenced Boat Design
The invention of the steam engine was, without a doubt, a significant step in the development of boat design. In addition to the use of high-pressure steam engines, which made boats more efficient, there was the introduction of double and triple expansion engines that improved travel efficiency.
The WWI and WWII also led to evolutionary changes in the way boats were designed. For example, hulls were made longer to enhance speed and were more protected from damage. Communication and navigation methods were also invented and were a crucial step in today's digital navigation and communication processes.
Modern Boat Design
Despite various evolutions in boat design, the basic structures of building sailboats remain the same if not consistent. There have been various changes but the most important aspects remain the same. They include
Structural features - The structural boat design revolves around how the various components of a sailboat are designed and how they interconnect with one another.
Contextual features - This revolves around the capacity in which the sailboat can operate in terms of advanced propulsion units, integration of new materials, and the use of safety and protection equipment. Such issues can influence the capacity in which the sailboat can operate. This also includes environmental concerns and that's exactly why your sailboat should be environmentally-friendly.
Behavioral features - This relates to how the boat is operated in terms of its performance, efficiency, and that of the crew based on external factors and how to respond to these factors. In the manufacture of modern sailboats, factors such as computational methods fall into this category and can influence how the boat is operated to enhance efficiency.
Perpetual features - This revolves around how the sailboat is designed and manufactured to satisfy your needs as the owner or the needs of those who will use it. This is where value comes into play as you want a vessel that will last for decades.
Temporal features - This is concerned with the performance of the sailboat and its system over time. As with anything else, the performance of many systems in a sailboat will reduce or diminish over time. This means that it's important to adopt a holistic approach to ensure that the sailboat is sustainable and can serve you without issues for many years to come.
Materials Used in Manufacturing Sailboats
Whether you're building a DIY sailboat or commercial sailboats, proper material selection is critical to the success and efficiency of the sailboat. Some of the most important factors to consider when selecting the right sailboat material include strength, efficiency, weight, speed, and corrosion resistance. The size and shape of the hull and the intended use of the boat can also influence the type of material that needs to be used.
For example, it would be very unwise to use steel in constructing a 30-foot sailboat as it would be extremely heavy. Similarly, you can't use aluminum if you do not know how to weld or at least not prepared to learn. That being said, the material used in constructing a sailboat should make it strong, yet rigid.
The sailboat should be able to perfectly take all the weight on its keel without unnecessarily distorting the hull. The boat should be able to stay afloat, which is possible by hardening up both the backstay and forestay without causing even the minutest of distortions on the boat's hull or any other part for that matter.
Let's look at some of the materials used in constructing modern sailboats.
Wood
Although not widely used in constructing modern sailboats, wood remains the traditional material used in building boats. The fact that it's extremely buoyant and easy to work with makes it a popular choice for the construction of small boats such as dinghies. While wood can easily weaken if water and other marine organisms are allowed to penetrate it, its resistance to abrasion hugely depends on its density and hardness. Fortunately, there are some types of wood such as Totara, Teak, and some types of cedar that have natural chemicals that prevent rotting.
In constructing a wooden sailboat, the planking used to construct the hull should be fastened to the frames and the keel. The keel and the frames must, however, be made of hardwood such as oak while the planking can either be oak or various types of softwood that do not rot easily.
The construction methods used when constructing a wooden sailboat include:
Clinker - This method was originally used by the Scandinavians. It revolves around fixing wooden planks to each other but with a small overlap that is beveled to make a tight fit. The wooden planks can also be connected to each other using screws, copper rivets, or modern chemical adhesives.
Carvel - This method revolves using a smooth hull made from attaching edge joined planks to the boat's frame. These planks should be caulked and covered with waterproof substance.
Whether using plywood or solid planks, they should be cold-molded using resin and wood strips. Keep in mind that can be an ideal option if you're looking for a material that can add acoustic, thermal, and aesthetic advantages to other materials such as metal. The wood should be saturated in resin not to eliminate maintenance issues but to reduce them.
Ferro-Cement Sailboat Hulls
Ferro-cement can be an ideal option if you're looking for a cheap hull option. However, you should avoid using them when constructing your sailboat as major issues often occur when the reinforcing rods start expanding as a result of rust caused when water penetrates the hull. Again, you may be wary about the cement having to be laid in one go to avoid weak spots on your sailboat.
Though labor-intensive, using Ferro-cement to construct your sailboat's hull can be a cheaper option. You, however, have to remember that it has its issues and some boat insurance companies do not insure boats that are made with Ferro-cement hulls.
Steel
Steel is among the most popular materials used in constructing boats, especially in the last century. The fact that it's durable, strong, resistant to abrasion, and affordable makes it a popular choice. However, it can be quite heavy and that's why composite materials that are cheaper, lighter, and just as strong as steel are widely preferred.
This is perhaps one of the main reasons why the importance of steel in constructing sailboats has significantly reduced in recent times. On the contrary, it's still widely used in constructing large cargo ships. In terms of sustainability and environment, steel can be an ideal choice in the construction of a sailboat. This is because it has almost no construction waste and is completely recyclable.
The fact that welding steel is easy makes it a popular sailboat material for amateur builders. It's also very cheap but very heavy. If anything, steel is 30% heavier than aluminum and even heavier than fiberglass. It can also rust, so you must protect it from water, using a special type of paint.
Aluminum
Aluminum is widely used in the construction of sailboats and a preferred option since it's a lot lighter than steel. Sailboats that are constructed using aluminum are said to be stable and seaworthy. They can also travel a lot faster than boats made from steel as they are much lighter. So if you choose to use fuel instead of relying on the winds, you can attain far more mileage using the same amount of fuel.
That's not all, aluminum is resistant to chemicals and corrosion so your boat is likely to be very durable and easy to maintain. It's also impervious to magnetism and deformations, which gives it an upper hand when compared to a lot of other materials.
On the contrary, aluminum is one of the most expensive options and may put a big dent on your bank account. It can also be prone to abrasion given its soft features but in terms of sustainability, it's one of the most environmentally friendly materials that you can consider in constructing your sailboat. This is because it's completely recyclable and will be okay if you use environmentally friendly paint instead of lead-based paint.
Polyethylene
This is one of the most versatile materials used in constructing sailboats. It can be used in various parts of the sailboat and the fact that it has a very high strength-to-density ratio makes it a popular choice. This material is also widely used in the construction of sailboats because it's low on maintenance, it is chemical and impact resistant, and is highly buoyant.
The material can also be easily molded to take various forms but cannot be ideal when used for fittings. But even with this, there are various reasons why polyethylene is not the number one choice as far as boat building materials are concerned. Well, the material is not as structural as aluminum, fiberglass, or steel.
This means that your boat will not be durable enough if it's constructed using this material. Again, polyethylene is likely to become brittle over time and will deform if it's exposed to high temperatures and this is something that you do not want for your boat. Worst still, polyethylene does not adhere to various bonding agents used in boat building including adhesives, epoxy resins, and vinyl cement. But even with all these drawbacks, polyethylene is recyclable and can reduce the weight of your sailboat because it is lightweight, and these are crucial elements as far as environmentally friendly is concerned.
Fiberglass
Fiber-Reinforced Plastic, commonly known as fiberglass, is seriously dominating the sailboat material sector in the last few years. This is because it is the best available option and offers numerous advantages when compared to other materials. Well, this material is lightweight, strong, durable, corrosion-free, watertight, and speedy.
Initially used by the military in the construction of warships, fiberglass can now be used in all levels of maritime applications and is a great alternative to wood, steel, and even aluminum. What's more, fiberglass is economically viable because it's cheap and durable, so it makes a lot of sense when used to construct a sailboat.
Fiberglass is also recyclable and does not have any negative effects on the environment or the marine ecosystem. With that in mind, fiberglass offers immense advantages, which is why more than 90% of modern sailboats are constructed using fiberglass. The fact that fiberglass is also compatible with many bonding materials only adds to its popularity.
We, however, have to note that there are still questions as to whether or not fiberglass works well with bolts. It's been reported that can slowly become loose with you being aware and this can be catastrophic as it happened years back when a boat called Cheeki Rafiki capsized and all the crew died while trying to cross the Atlantic. This tragedy rocked the sailing world and raised questions on the safety of fiberglass. The best thing to do to avoid such tragedies is to ensure that the boat is maintained accordingly.
To this end, the best material for constructing a sailboat is heavily debated. Well, that's because each material has its pros and cons. As such, many boat builders choose to use a mix of material to create an ideal sailboat and we believe that it is the best way to go.
