Boat building tools

Boat building uses many common house tools such as hammers, crosscut saws, power drills, benches and vises.

For building small boats under 5m some specialized tools are needed such as clamps (cramps) either G clamps or spring clamps. Flat and round surform rasps are useful tools for shaping wood and ply. A drill set from 2-10mm, several speedbore drills for larger holes 12-25mm, (1/2inch-1 inch) rotary sanding backing pads and a range of replacement sanding pads from coarse (40grit) to fine (180grit), counter sinking drills for screws, a right angle set square, a set of manual screw drivers with blades to match screws being used are essential. A heavy craft knife, an 8 m (26 ft) tape, flat and round files for metal and wood, a short (torpedo) level and a set of three chisels from 6 to 25mm are needed. Power tools make a job much easier and are relatively cheap. An 7 ¹⁄₄ inches (180 mm) circular saw with a fine 40 tooth tungsten carbide blade, a jigsaw with a dust blower with a set of fine, medium and coarse tooth metal and wood blades is good for cutting plywood panels to shape, a rotary oscillating sander with medium and fine pads and a cordless drill for driving screws all save time and energy. A steam box is excellent for making planks easier to bend although hot wet rags are a messy, but easy substitute. A fine tooth hacksaw is not only essential for cutting metal such as trimming stainless steel bolts to the correct length but is handy for ultra-fine cuts in thin wood. A fine-tooth tenon saw is used to cut across the grain to produce a reasonably fine, accurate cut. Some boat builders have started using Japanese draw saws for fine cuts but while these are excellent they tend to be very expensive. A No 4 smoothing plane is essential but an electric plane is very useful (but extremely loud) for making rudder blades and centre boards. A much longer No. 7 plane is needed if the design calls for a wooden spars as used in many modern "traditional" yachts.

In boat building lots of sanding requires using either dry sandpaper, or wet and dry paper, to achieve a reasonable paint or varnish finish. Sandpaper is graded from 40 (very coarse) to 400 (ultrafine). Wet and dry sandpaper lasts longer than dry sandpaper. Wet and dry is best used on paint finishes, while dry paper is best used on dry wood. About two sheets of sandpaper for every foot of hull length is a good guide. Less sheet sandpaper is needed if power sanders are used. Spatula applicators, with a flexible stainless steel blade, are used to apply filler. A knife type and a flat 3" (75mm) type will cover most needs.

Silicon bronze screws are normally used in boat building but can be hard to locate. Brass fasteners are commonly available but apart from being softer and weaker the common brass alloys are much more prone to corrosion through depletion of their zinc content. Stainless steel screws may be used for attaching fittings to the hull above the water line. Type 316 stainless steel is the only stainless steel recommended. Even 316 may get stained with surface rust but this does not penetrate the surface. Staining comes from being in contact with other steels such as the anchor or incorrect cleaning in the factory. Staining near wields should be removed as it can pit. Experienced boat builders are reluctant to use even 316 below the water line in a boat permanently in salt water. This especially applied to long thin fastenings such as screws in boats that have motors. Sacrificial anodes are used to help prevent corrosion underwater but experts will inspect a sample of long thin screws or bolts annually to check for corrosion.

Epoxy resins and hardeners are universally used in boat building due to their superior holding power and ease of use.[1] In its thickened state it is used as a strong filler and for a range of joints that do away with more traditional fastenings. A large supply of cheap wooden tongue depressors is useful for mixing and applying epoxy resin. The curved ends are useful for shaping coved joints with epoxy. Silicon bronze ring nails are excellent for permanent fastening of wood and ply as they are strong and easily driven. Many small boats are almost entirely fastened by epoxy resin. In stitch and glue construction the hull panels are temporarily held together with either copper wire, nylon fishing line or plastic cable ties, until the epoxy cures, after which the stitching material is removed. Polyester filler is a quick setting (20min), softer filler, suited to very small holes and scratches and is far more easily sanded to a fair shape than harder, stronger epoxy filler which takes 24 hours to set hard.

Boat building requires enough space, under cover, so that the builder can easily move around the hull during construction, or the boat can be built on a trailer so the hull can be moved out of the shelter for construction sessions. It also requires space at the bow and stern not only for working but for sighting down the gunwale and chine lines to check they are fair. Have the bow at the garage door end for this reason. This is especially important in stitch-and-glue construction where no jig is used, as the ply panels are very floppy until the glue sets.

Water-based paint is far easier and cheaper to apply, as undercoat, to produce a good smooth finish with a fraction of the time and effort of enamel paints, but harder and slower-drying enamel is best for the top coat on the outside of the hull, which is subject to a lot of bumps and scraps. Limit varnishing to smaller areas, such as grab rails, hatches, toe rails and trim, unless one has lots of patience and a very dust-free environment for varnishing. Use only marine gloss varnish on the outside, as interior varnish will peel off very quickly in hot sun and rain. Marine varnish has UV inhibitors to slow down peeling and fading. Never varnish a deck as it is slippery when wet. Even top-quality marine varnish is not as water-resistant as paint, so at least four coats must be applied. Often perfectionists will apply 8 coats or more to get a glass-like, reflective finish. Never varnish submerged parts like rudders.

Boats take a long time to build as there are almost no right angles. Amateurs working at night or in weekends commonly take a year to build a 12–16 ft (3.7–4.9 m) craft. Builders with handyman skills will find that over time their skills will increase. For amateurs, starting with a boat built on a jig (temporary wooden frame) is useful as making the jig is all about right angles and basic carpentry skills. Sailboats require about 25% more time than a dinghy type because of the need for built-in buoyancy, centreboard case, centreboard, rudder, mast, boom and a range of special fittings such as chain plates, gudgeons, blocks cleats and tracks.

Essential safety gear needed is closed-in footwear, very high grade ear protectors (especially if using a high-revving electric plane or router), eye shields when cutting or grinding metal, disposable gloves when gluing, close-fitting clothes that will not get caught in drills. Good light is essential. Boat builders should not work when they are tired and should keep the work floor clean so they don't trip over tools or wood or electric leads. A fan is handy for extra ventilation if the work space does not have many opening windows or doors. Many boat builders like smaller tools to be bright-coloured tools so they can see them easily amongst saw dust.[2] With the recent technological advances in materials being used in modern boat building including GRP and FGRP respiratory protection masks have become essential in many workshops. The only suitable alternative being substantial dust extraction equipment by means of on-tool extraction or a fully fit out environmental cleaning workshop installation.

Other useful power tools are a belt sander, especially if using recycled timber or for finishing rough-sawn timber. A thicknesser/planer is only needed if building many boats or larger vessels, as it is usually cheaper to pay a joiner to do this for a small amount of timber. A bench saw is useful if one buys larger sectioned timber, which may be considerably cheaper and need to saw it to the correct size, but again a timber yard will do this for a small charge.[3]

References

1. West System International http://www.westsysteminternational.com/en/welcome/an-illustrated-history
2. New Zealand Backyard Boat Builder. J Welsford. Reed. 1999.
3. Backyard BoatbuilderJ Welsford. Reed.1999.

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