Sep
13
Posted under
Wooden Boat Building
Methods of Wooden Boat Building
For a Wooden Boat to be successful it needs to be built of timbers joined in such a way that they provided a hollow interior with a water proof outside shell. Either the method of joining the timbers and/or an internal framework must provide structural integrity. The structural integrity must be able to resist both static forces (i.e. the boat must be self supporting both longitudinally and in cross section when at rest) and also must be able to resist the enormous dynamic forces of wave and wind on the hull, superstructure and any rigging.
The following methods of Wooden Boat Building use differing techniques and hull designs to achieve the desired results.
Clinker or Lap Strake Built Boats.
The Clinker or Lap Strake built boat is the type of construction used most beautifully by the Vikings when building their longships. It is an excellent lightweight method of boat building, a method which is most often used today in dinghies and small craft.
In this method the boat is built from longitudinal planks with the bottom edge of one plank overlapping the top edge of the one below. The planks are joined at the overlap with rivets, clenched nails or glue. The overlapping of the planks provides for excellent stiffness and means that internal framing can be kept to a minimum, which creates a light sturdy boat. The method often allows for the hull to be built first and the strengthening internal frame to be fitted afterwards.
Modern Plywood construction of clinker or lap strake hulls often uses resilient, flexible, easily worked marine grade plywood with epoxy being used to bond the planks. The epoxy provides bonding, filling and protection all at once, allowing the speedy building of a vessel which has the beauty and strength of wood and a superb low maintenance finish.
It was not unusual for older clinker boats built of natural timber to need “soaking” in order for the timber joints to swell and so become water tight. This has been eliminated with the use of modern epoxy bonding.
As the size of a Lap Strake boat increases, the thickness of the planking required and the size and weight of the internal bracing grows to an extent that the Carvel Built boat provides a far more efficient use of timber and better structural integrity.
Carvel Built Boats
A Carvel built boat is one in which the internal structural frame of the boat is created first and then the planking is attached. The planking consists of longitudinal timbers which are fitted and attached to the preformed timber frame. They are joined edge to edge, with no overlap (butt joined). The joint between the planks is sealed by caulking or by a specially designed timber fillet inserted in a groove in the edge of the planks.
This is the method which was and still is the most common form of building larger wooden boats and commercial ships. The frame of the boat and timbers required for construction can become quite massive as the size of the vessel increases.
Plywood on Frame
The introduction of Waterproof plywood has seen the development of “ply on frame” and then later even “frameless plywood” boats being designed and successfully produced. These methods are ideally suited to the amateur or novice builder because they allow for a quick and relatively easy build taking full advantage of modern cheap power tools.
The frame of the boat may be constructed of timbers or may be cut out of plywood sheets, which provides a form of internal bulkhead. The use modern epoxy glues which give waterproof joins which are often much stronger than the timber itself also speeds the building process.
Stitched Plywood
The stich and glue building method where the plywood joints are held together by either wire or plastic ties and the joint is covered with fibreglass and epoxy is a popular modern building method. This has lead to the design of plywood boats which are frameless, relying on the integrity of the bonded hull to provide structural strength. This means an extremely lightweight hull can be designed.
Cold Moulding
Cold moulding is another modern method taking advantage of the superb characteristics of modern epoxy bonding materials. In this techniques a minimum of two layers of thin strips of timber (usually plywood or veneer are laminated on top of each other. The layers run in different directions, usually in a diagonal pattern. Often insulation is bonded between two outer layers and an additional inner layer. This method requires a preformed mould on which to build the boat and this extra work usually precludes the amateur builder. The method does however produce beautifully lightweight hulls which are very strong. Often vacuum forming is used to provide an extra fine finish and ensure the close bonding of the timbers.
Technorati Tags: Boat Building, Wooden Boat Building, Wooden Boats
Sep
06
Posted under
Build Your Own Boat,
Wooden Boat Building
Why wood? Wooden Boat Building may seem old fashioned with a choice of modern materials such as Aluminum or Steel or Glass Fiber reinforced Polyester Resin (fiberglass) but; as a material for building boats and small ships; wood has a number of significant advantages over the other alternatives.
The first is the fact that wood has the highest Quality Coefficient for boat building. What does that mean? It means that for a given size a properly built wooden boat will be the strongest for any given weight. When comes to resisting the stress place on hulls by the pounding of waves and water, tests have shown that wood is nearly twice as resistant to these stress’s as the other materials.
Wood also has the best thermal and acoustic properties of any boat building material. You don’t find condensation running down the inside of your wooden boat nor do you have to listen to drumming caused by the slap of waves on the hull.
Wood also has no galvanic corrosion problems.
And of course nothing is as pleasing to the eye as beautifully finished timber; notice that the best builders in all the other materials still use timber in their interior fit-outs.
Given that wood is also buoyant, relatively cheap, and widely available and easily worked and is particularly suited for small boats (up to about 6 meters in length) it is no wonder that Wooden Boat Building is especially popular with amateur builders. Timber can be worked with the simplest of tools; most of the work can be done with only cheap hand tools. The natural bending characteristics of wood mean that pleasing smooth, symmetrical lines can obtained without special moulds or bending equipment.
Other natural characteristics of wood such as its durability and resilience make it ideal for boatbuilding. If properly maintained and protected from the elements and marine or freshwater organisms a wooden boat will last a lifetime.
The question might be asked if wood is so good a boat building material why are there so many fiber-glass and aluminum boats around. The answer probably comes down to the ability to mass produce such boats. When the cost of labor is taken into account a wooden boat can be much more expensive. An aluminum or even steel boat can be made quickly out of stamped or prefabricated sections assembled on a jig and welded together and a fiberglass boat is built in a mould with a combination of woven and chopped glass-fibre being encased in plastic like resin.
That is not to say that these techniques and materials are inferior for boat building (the vast majority of new boats are built from one of these materials and cost alone is not the only reason) but they are more suited to production line methods than to one off efforts.For the amateur builder the cost of specially made moulds (for fiber-glass) and welding equipment, special templates or jigs and specialist skill (aluminum welding) quickly push the advantage towards wood as the building material of choice for the one off home builder.
You can join the many thousands of people engaged in Wooden Boat Building, taking advantage of the ready availability of wood in most parts of the world.
Next time I’ll explore some of the many different methods of Wooden Boat Building.
Technorati Tags: boat builders, Boat Building, wood boat building, wooden boat, Wooden Boat Building
Sep
04
Posted under
Wooden Boat Building,
Wooden Boat Building Involvement
Wooden Boat Building involving a wooden ski boat restoration.
My third experience in Wooden Boat Building was being involved in the restoration of work on some friends 1950’s inboard powered wooden ski-boat.
When I was about 17 years old the family of some very close friends, purchase a second hand wooden ski-boat and so began what was a long term involvement with the maintenance and “restoration” of this wooden boat. Read the rest of this entry »
Technorati Tags: Wooden Boat Building
Sep
03
Posted under
Build Your Own Boat,
Wooden Boat Building
Some Wooden Boat Building ventures begun by people who started their project with little or no conception of what they were undertaking; and who through sheer determination and bull headedness managed to finish; do end up producing a work of art, but more often the venture ends in tears and frustration.
So I advise that very careful reflective consideration before you begin is a must. Read the rest of this entry »
Technorati Tags: Build Your Own Boat, wood boat, wood boat building, Wooden Boat Building
Sep
01
Posted under
Build Your Own Boat,
Wooden Boat Building
Answer these 10 most Important Questions Before you begin to Build Your Own Boat
These are fundamental questions that you should consider before beginning your Wooden Boat Building Project. They have been distilled from reading Blogs, Forums, Comments, and from first hand experience; seeing people begin projects that never get completed and some that were completed but at enormous financial and or emotional cost. Some of these questions may seem stupid, some you will have already considered, and some you may be tempted to dismiss but all are important. There are unquestionably many more but these are my personal list.
My top ten things that need to be considered carefully before you start a wooden Boat Building Project. Read the rest of this entry »
Technorati Tags: boat builders, Build Your Own Boat, wood boat, wood boat building, wood boat restoration, wooden boat, Wooden Boat Building
