50% developed  as of April 22, 2006

Do-It-Yourself/Wooden boat – Wikibooks, open books for an open world

By David Moss
50% developed  as of April 22, 2006 (April 22, 2006)

Choosing a design[edit]

The design (format) concerned for this venture would possibly simply be essentially the most tough a part of the entire course of.

Your first boatbuilding venture needs to be easy and cheap, but the boat must be helpful when it’s completed. The steadiness between these standards is a person resolution. The Web is a good place to start out when searching for a design. A web site I discovered helpful at no cost design data was http://residence.clara.internet/gmatkin/design.htm.

In my case I selected the “Dug”, designed by Hannu Vartiala. Free plans can be found on the internet at Hannu’s Boatyard: http://koti.kapsi.fi/hvartial.

Dug canoe.JPG

I selected the Dug as a result of I needed one thing easy and cheap as my first boatbuilding venture. It’s created from a single sheet of plywood so it doesn’t get any cheaper, and the design on the web site seemed straightforward to comply with.

I modified the design to make use of 3mm plywood somewhat than 6mm. Not solely was the thinner ply cheaper, nevertheless it was a lot lighter. It additionally gave me the chance to experiment with becoming gunwales.
The completed product was a one individual canoe. I can choose up and carry this boat simply on my own and it virtually floats on moist grass. It’s good for fishing within the shallow rivers across the headwaters of the Murray Darling system in Queensland, Australia.

The Dug was my selection, although. Your individual selection of design in your first boatbuilding venture could be completely different.

Plywood[edit]

Plywood is a person made building materials. It often consists of an odd variety of layers of skinny timber veneer glued along with the grain of alternate layers working at 90° to one another. The outermost layers are termed the faces. Since these are the one seen layers, the looks of every face is topic to straightforward specification. In Australia every face of a plywood sheet is described by a code letter:

  • A — a top quality look grade veneer appropriate for clear ending.
  • S — an look grade veneer which allows pure traits comparable to knots as an ornamental function topic to settlement.
  • B — an look grade appropriate for top of the range paint ending.
  • C — a non-appearance grade with a stable floor. All open defects comparable to knot holes or splits are crammed.
  • D — a non-appearance grade with permitted open imperfections. Restricted numbers of knots and knot holes as much as 75 mm extensive are permitted.

Marine plywood that meets the AS/NZS 2272 commonplace has two A grade faces and an A or B grade core.

Within the USA some producers use a letter code for the “entrance” face and a corresponding quantity for the “again” face, i.e. a code of AB in Australia could also be specified as A3 within the USA.

Typical functions utilizing this grading commonplace are AA for marine plywood, AD for a wall cladding the place solely the entrance face of the plywood is seen, CD for structural plywood flooring and DD for structural bracing.

The adhesive used to bond collectively the laminations within the ply is of paramount significance to boatbuilders. There are 4 commonplace glue rankings:

  • Sort A bond is produced from a phenol-formaldehyde resin [PF] which units completely beneath managed warmth and stress. It varieties a everlasting bond that won’t deteriorate beneath moist circumstances, warmth or chilly. It’s readily recognisable by its black color. Sort A bond is laid out in AS/NZS 2272 for marine plywood.
  • Sort B bond is produced from melamine fortified urea-formaldehyde resin [MF] which units beneath managed warmth and stress.
  • Sort C and Sort D bonds are inside use bonds produced from urea-formaldehyde resin [UF] and shouldn’t be utilized in boatbuilding.

Plywood for boatbuilding is historically bought in eight foot x Four foot sheets. In metric this rounds out to 2400mm x 1200mm.

It’s obvious from these dimensions that it’s vital to hitch plywood sheets collectively to construct even the only of boats.

Exterior grade ply[edit]

Exterior ply is manufactured in accordance with AS/NZS2271 from quite a lot of supplies together with hardwoods and ornamental veneer facings comparable to Sapele, White Ash, Teak, or inlaid Teak and Beech.

It isn’t manufactured to the identical engineering requirements as marine ply however is commonly fairly appropriate for a primary boatbuilding venture. The glues used between the layers are the identical as these utilized in marine ply so delamination shouldn’t be an issue

Exterior grade ply could have one “good” face and the opposite of lesser grade, for instance AB.
The “Dug”, my first boat, was constructed utilizing exterior grade ply in pacific maple.

Marine ply[edit]

Marine ply is an engineering product that should adjust to revealed requirements. In Australia the related commonplace is AS/NZS2272. Within the USA, the UK and different components of the world the BS1088 commonplace could also be used to specify marine ply. These requirements element virtually each side of the composition and efficiency of marine ply. If you’re going to construct a seaworthy boat, or a ship that should meet survey requirements, use of a licensed marine ply is important.

Within the Australian/ New Zealand Requirements system for veneers and bonds marine plywood has a grading of AA – A bond and may have the ‘PAA Examined marine’ stamp utilized to the sheet. If it’s not stamped then it’s more likely to be materials which has not handed last inspection.

Some examples of marine ply accessible in Australia are:

  • Hoop Pine: AS 2272 Commonplace, Australian made premium plywood.
  • Gaboon: BS1088 and BS3655 Requirements, mild weight plywood having Lloyds Register certification.
  • Mahogany: BS1088 Commonplace, premium plywood
  • Pacific Maple: BS1088 Commonplace, essentially the most economical however barely heavier plywood.
  • Cortech: Balsa-cored plywood, has a really excessive stiffness to weight and power to weight ratio. To be used in boat hulls, decks and so on.
  • Veneered Plywood: Waterproof plywood with teak, ash and sapele ornamental veneer. Additionally teak/ash striped plywood for boat soles and decks.

Becoming a member of Plywood sheets[edit]

Plywood for boatbuilding is historically bought in eight foot x Four foot sheets. In metric this rounds out to 2400mm x 1200mm. It’s obvious from these dimensions that it’s vital to hitch plywood sheets collectively to construct even the only of boats.

Two strategies are generally used to hitch plywood sheets collectively:

  • The butt joint
  • The headscarf joint

The butt joint is by far the best to make. It’s shaped by making use of liquid epoxy to the sides of the sheets to be joined, pushing them collectively and gluing a strip of ply to 1 or each side of the seam.

Buttjoint.jpg

A variation is to make use of fibreglass tape as a substitute of the strip of ply. As soon as the epoxy has cured the be part of is stronger than the plywood sheets themselves and the wooden will fail beneath stress earlier than the epoxy of the joint.

Trace: Epoxy doesn’t keep on with polyethylene. Laying down a sheet of polyethylene movie, comparable to a disposable painters drop sheet, can save the embarrassment of gluing your work to the ground when becoming a member of sheets.It’s also possible to use baking paper for this goal if polyethylene is just not accessible.

Lofting[edit]

Lofting is the method of taking the size from a plan and drawing full dimension elements on the development supplies.

Utilizing the lofting batten

Generally the designer gives the required measurements within the type of a desk, however typically it’s essential to take the measurements straight from the drawing and scale them as much as life dimension.

First a centre line is marked, then collection of station strains are drawn on the ply at common intervals 90° to the centre line utilizing a set sq.. Station strains could also be drawn each 10cm for instance. The distances both aspect of the centre line at every station line are decided from the plans and marked on the ply as reference marks. Lastly clean lofting strains are drawn by the reference marks. A straight edge comparable to a metal ruler could also be used for straight strains and the lofting batten is used for clean curves. It’s useful to briefly drive panel pins into among the reference marks to make sure the lofting batten follows the right curve.

As soon as the lofting course of is full the lofting strains are used as reducing guides when the elements are minimize from the sheet.

Epoxy is the fabric that makes wood boatbuilding doable for the common individual. It’s used as an adhesive, a structural part, and to seal the wooden to cease it absorbing water.

Wikipedia has an article about epoxy at http://en.wikipedia.org/wiki/Epoxy.

The WEST System[edit]

The Wooden Epoxy Saturation Method, or WEST system, is a way for sealing a wood boat in opposition to the ingress of moisture. A skinny layer of liquid epoxy is utilized to the wooden like paint. Among the epoxy is absorbed into the grain and the pore construction of the wooden whereas the epoxy is a liquid and when it hardens the wooden is successfully protected by a moisture proof barrier.

The WEST System is a generic boatbuilding method, but additionally a registered commerce title for a model of epoxy merchandise manufactured beneath license from Gougeon Brothers, Inc. USA. The Gougeon Brothers developed the epoxy coating of the unique WEST system together with DOW Chemical compounds within the late 1960s. Since that point epoxy programs, together with the WEST System model, have undergone vital improvement. Right this moment there may be a variety of producers providing epoxy programs for wood boatbuilding. An online search utilizing the time period boat constructing epoxy will return 1000’s of references, tailoring the seek for your personal location ought to return greater than sufficient native epoxy producers to select from.

A phrase of warning nevertheless. Not all epoxy formulations are appropriate for sealing a wood boat in opposition to moisture. Marine coating epoxies typically don’t embrace natural solvents or thinners. They might be described as excessive solids epoxies. The reason being that natural molecules are a lot bigger than water molecules. When natural solvents evaporate from the liquid epoxy throughout curing the departing molecules could depart microscopic tunnels that permit a lot smaller water molecules to enter. This reduces their effectiveness as a moisture barrier and makes them unsuitable to be used as a marine coating.

When constructing my first wood boat I selected Bote Cote, a excessive solids epoxy produced by an organization in Brisbane, the closest main metropolis to my residence. My selection was principally influenced by comfort, fame for high quality, and the need to help an area enterprise. Your selection of an epoxy system could also be influenced by related concerns however as long as you select a top quality epoxy appropriate as a marine coating, the selection is yours.

Mixing Epoxy[edit]

Essentially the most vital a part of the epoxy course of is mixing the correct quantity of hardener with the epoxy resin.

Saved individually the hardener and the resin will keep in liquid kind. When combined collectively the hardener acts as a catalyst and induces the resin to polymerise, or kind cross linkages between its molecules. As these bonds between the molecules kind the viscosity of the combination will increase and ultimately, after a number of hours, it solidifies. The response continues for a number of days afterward so it is crucial to not apply extreme stress to the fabric for no less than 24 hours after software.

The speed at which the polymer bonds kind depends on the chemical properties of the hardener used and the ambient temperature. The response that varieties the bonds is exothermic which suggests warmth is generated every time a brand new bond is shaped. The warmer it’s, the quicker the bonds kind and the warmer it will get, so new bonds kind even quicker. The warmth often escapes to the encompassing air by conduction so it is very important unfold the epoxy out in a tray somewhat than preserve it in a pot after mixing. The better floor space of the tray permits extra warmth to flee and will increase the pot life, the time when the combination remains to be skinny sufficient to use successfully.

The pot lifetime of a batch of epoxy is mostly about 45 minutes. As soon as a batch has reached the top of its pot life it’s not doable to use it, so it should be discarded. It is sensible to combine up small portions of epoxy at a time. Solely combine up as a lot as you may comfortably apply through the pot life or you’ll waste a number of costly epoxy.

Polyethylene containers comparable to these utilized by some takeaway meals retailers are wonderful mixing pots for epoxy. Epoxy is not going to keep on with polyethylene so it’s straightforward to peel out the skinny layer of hardened epoxy subsequent day and re-use the container.

You will need to comply with the producers instructions about mixing ratios precisely. Including roughly hardener to the combination is not going to have an effect on curing time or pot life, however it’ll scale back the power of the bond.

Additionally it is necessary to make use of the kind of hardener the producer recommends for the ambient temperature of your workshop. Bote Cote advocate the next hardeners to be used with their epoxy system:

Quick Hardener: To be used in southern Australian climates and in winters, has a pot lifetime of 45 minutes and a skinny movie set time of 5-6 hours at 14-16 deg.C. Can be utilized at temperatures as little as eight deg.C.
Commonplace Hardener: Appropriate for hotter circumstances and southern summers, has a pot lifetime of 45 minutes and a skinny movie set time of 5-6 hours at 20-22 deg.C.
Tropical Hardener: For warm climates comparable to northern Australia the place temperatures not often fall beneath 30 deg.C. and there may be constantly excessive humidity. Has a pot lifetime of 45 minutes and a skinny movie set time of 4-5 hours at 30 deg.C.

Metric conversion trace: go to google.com and kind “20C in F” within the search field.
This neat trick works in changing many different items too. (you may check out the instance right here)

Some producers additionally provide a hardener accelerator. For Bote Cote the addition of two% accelerator doubles the reactivity (half the pot life) whereas 4% makes it react Four occasions as quick. The accelerator is just not a substitute for hardener, it simply speeds the method. This may be helpful when you may have a provide of tropical kind hardener however need to use it with epoxy on a chilly day in winter.

No matter epoxy system you select it is very important comply with the producers instructions precisely when mixing.

In my case the combination ratio was two components of epoxy resin to 1 half hardener. Whereas it’s doable to combine epoxy to the right ratio utilizing measuring cups, or by weight, I made a decision to buy measuring pumps once I purchased my epoxy.

Epoxy system and fibreglass tape

Two hand operated pumps had been required, one for the epoxy resin and one for the hardener. The pumps had been cheap (round AUD$10 every), match straight on to the bottles, and I’ve by no means regretted the choice. Mixing was merely one squirt of hardener to each two squirts of epoxy resin. I extremely advocate measuring pumps to anybody intending to construct a wood boat.

As soon as the epoxy and hardener has been distributed within the right ratio it’s important to ensure it’s completely combined. Stir the combination fastidiously for a number of minutes with a flat, disposable stirrer. Some skinny plywood offcuts trimmed to dimension are perfect.

When the epoxy is completely combined many individuals switch it to a different container earlier than software, even when the amount is just too small to fret about it exotherming within the mixing pot. The explanation for that is regardless of how cautious you’re with mixing, there’ll all the time be some unmixed epoxy resin or hardener adhering to the perimeters of the pot, or proper down within the corners. If a single drop of this unmixed resin finds its means on to your work it’ll lead to a sticky spot that may by no means treatment correctly. Murphy’s legislation dictates the sticky spot will happen within the worst doable a part of your floor. Pouring the combination right into a clear container and giving it a last stir with a clear stirrer is reasonable insurance coverage in opposition to undesirable sticky spots within the epoxy.

Thickening Epoxy[edit]

Correctly combined epoxy is a really runny liquid. It’s perfect for portray on to wood surfaces, however typically its low viscosity can current an issue. Build up a fillet within the be part of between a horizontal and a vertical floor is not possible with out the addition of a thickening agent.

Epoxy producers promote quite a lot of thickening brokers. Bote Cote provides the next fillers that can be utilized to thicken epoxy in numerous conditions:

Excessive Energy Filler: A excessive density glass fibre and particle filler for max power gluing functions comparable to catamaran beams, mast bulkheads, load carrying transoms, and so on.
Glue Filler: A low price blended filler used for many gluing functions and likewise for making all fillets.
Fairing Filler: A low density, simply sanded microsphere primarily based filler, which spreads like cream to an ideal feather edge. Used for filling and fairing.

Most producers provide their very own variations of those filler merchandise.

Some producers additionally provide wooden flour for thickening epoxy. Hannu’s Boatyard, the location the place I sourced the plans for my first boat, advised plain outdated wheat flour as an efficient epoxy thickener. That’s what I used when constructing the “Dug” and it labored simply tremendous.

As soon as the epoxy has been completely combined, merely add your chosen thickener a bit of at a time, stirring constantly, till the combination reaches the specified consistency. It is sensible to make use of as little thickener as doable according to the appliance. Each particle of thickener within the combine is a particle that doesn’t kind polymer bonds with the encompassing epoxy. The much less thickener within the combine, the stronger the fabric will likely be when it hardens.

I added ample plain wheat flour to carry the epoxy combination to the consistency of peanut butter with a purpose to kind the fillets wanted on the “Dug”.

Instruments helpful in developing the boat included

  • Energy drill
  • Energy jigsaw
  • Energy aircraft
  • Random orbit sander
  • Handsaw
  • Hand aircraft
  • Hand sanding block
  • Clamps (plenty of them)
  • Lofting batten (an extended, straight, versatile strip of wooden to assist in drawing even curves)
  • Set sq.
  • Metal ruler
  • Tape measure

Protecting gear[edit]

  • Particle masks
  • Security glasses
  • Disposable plastic gloves
  • Shut weave work clothes

A particle masks is important. There’s a number of sanding in boatbuilding and the mud it generates is just not good in your well being. Wooden mud itself is dangerous sufficient, however while you add epoxy mud and fibreglass mud you’ll positively need to preserve it out of your lungs. You should purchase disposable paper particle masks fairly cheaply at {hardware} shops.

Security glasses are extremely really useful. Personally I put on prescription glasses so I don’t have to fret about particular security glasses. Folks lucky sufficient to not want spectacles ought to contemplate buying a pair of security glasses earlier than utilizing chemical compounds like epoxy and hardener.

Disposable plastic gloves are additionally a good suggestion if you find yourself mixing or making use of epoxy resin. Some individuals quickly turn into sensitised to epoxy and develop dermatitis. Disposable plastic gloves forestall pores and skin contact from occurring within the first place and keep away from potential well being issues. Disposable plastic gloves can be found cheaply at main grocery store chains.

Shut weave work clothes with lengthy sleeves and lengthy trousers is extremely really useful. If you’re contemplating greater than only one boatbuilding venture it may be sensible to put money into mild cotton overalls. I made the error of sanding fibreglass bolstered joints carrying solely a pair of shorts. This was very snug on the time within the sizzling Queensland summer time, however very uncomfortable for over every week afterwards when the glass fibres within the mud made their presence felt. Ever since I’ve worn cotton drill work garments with sleeves down whatever the temperature!

Sew and Glue[edit]

Sew and glue is a way for developing advanced three dimensional objects utilizing plywood and epoxy resin.

The sew and glue methodology was developed by the primary tv “do it your self” (DIY) professional, Barry Bucknell, in about 1964. Wikipedia has an article about sew and glue at http://en.wikipedia.org/wiki/Stitch_and_glue.

The sew and glue method

First a row of small holes about 10cm aside is drilled near the sting of one of many mating items of plywood. An identical gap is drilled within the different piece adjoining to every of those holes as building proceeds and the 2 items are stitched collectively utilizing both copper wire or plastic cable ties.

As soon as the mating items have been stitched collectively a fillet of epoxy is utilized to the joint, gluing the items collectively. Within the photograph on the proper a bit of waste plywood with a radius sanded on to 1 nook is getting used to unfold thickened epoxy into an excellent fillet.

Should you look carefully on the {photograph} you’ll discover the sides of the mating plywood items are darkened. It is because the sides had been wetted out with a lightweight coat of liquid epoxy earlier than the thickened epoxy of the fillet was utilized. The unthickened epoxy wicks into the grain of the plywood permitting better adhesion. Since each the thickened and unthickened epoxy treatment collectively they kind a single polymerised construction of nice power. In reality the joint shaped is stronger than the plywood itself. As soon as cured the wooden will break earlier than the epoxy of the joint if ample power is utilized.

When the epoxy fillet has cured the stitches are eliminated. The holes crammed and the addition of fibreglass tape and extra epoxy gives the required degree of structural power to the joint.

Portray[edit]

Portray a wood boat is greater than only a beauty impact. The paint varieties a necessary a part of the boat’s construction.

If a wood boat is just not sealed in opposition to moisture it’ll take in water, the wooden will swell up and extreme harm can happen.

Most wood boats immediately are sealed in opposition to water utilizing a skinny coat of epoxy. Epoxy does a terrific job sealing out moisture however is prone to break from ultraviolet mild (UV). Unprotected epoxy will likely be broken by the UV rays in daylight and begin to deteriorate in a single season.

Happily most exterior grade paints supply good safety in opposition to UV mild in addition to added safety in opposition to moisture ingress.

Choosing a paint[edit]

Choosing a floor end in your boat is a posh process. Should you go right down to your native ironmongery store and ask for a paint that’s good over epoxy you’ll most certainly be greeted with a clean look. Only a few paints particularly state they are often utilized to epoxy. The excellent news is that almost all paints will stick properly to epoxy regardless of the dearth of formal specification. Success depends upon floor preparation nevertheless.

Folks usually change their minds about floor end through the building of the boat. They begin out with a imaginative and prescient of the boat painted in stable covers, however through the building course of the fantastic thing about the timber is revealed, particularly within the areas the place unthickened epoxy has been used. Epoxy varieties a clean, clear, shiny floor that enhances the grain of timber. Its too dangerous it may possibly’t simply be left as-is however sadly it breaks down rapidly when uncovered to UV mild. Epoxy should be protected by a coat of UV stabilised paint or varnish if it will likely be uncovered to daylight.

Some floor finishes which have been advised for marine use are:

  • standard-type marine enamels
  • silicon/alkyd sorts
  • epoxy paints
  • one or two-part urethanes
  • Linear polyurethane

Every of those floor finishes has its personal benefits and downsides. For my first venture I chosen a latex kind exterior acrylic home paint. It was comparatively cheap, shaped a clean medium gloss end and adhered properly to the WEST handled plywood of the boat.

Some producers advocate the usage of etching primer earlier than the appliance of their product. This ignores the truth that cured epoxy is chemically inert. Etching primers, which depend on a chemical etching motion, don’t have any impact by any means on cured epoxy.

The one solution to obtain good paint adhesion on cured epoxy is to frivolously sand the floor previous to software, making tens of millions of microscopic scratches on the floor. This facilitates mechanical keying of the paint to the floor, lowering the possibility of peeling.

Preparation[edit]

Earlier than doing any ending work or making use of finishes, permit the final coat of epoxy to treatment 5 to 7 days if the ambient temperature is above 20°C, even longer at colder temperatures. (There’s a number of ready in all facets of boatbuilding)

Some epoxy programs endure from amine blush, a greasy substance that varieties on the floor throughout curing. In case your chosen epoxy system suffers from this drawback, wipe down the work with a water/ammonia dampened rag or sponge previous to sanding. It will eradicate the greasy amine blush, make sanding simpler and reduce clogging of the abrasive paper.

Utility[edit]


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