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Copyright 2009 DIY Ballistics

Plywood Construction

Let's keep things simple here. There are many types of wood that are used in boat construction. For the beginning boat builder, lumberyard material is a great way to go. I have built many plywood hulls using lumberyard wood and almost all of these boats are still seeing active service. But, and there has to be a but, these boats are all kept well maintained. Paint every spring, stored upside down on saw horses or blocking, and well ventilated to keep things dry. The ones that haven't survived are those that I just beat the life out of knowing that I was going to get my money's worth many times over. Your boat, your call.
I have no problem using lauan plywood for hull construction. I did some destructive testing of my own and was satisfied with my results. Be advised though; the lauan needs to be sealed throughout, preferably with epoxy. I have used just paint as a sealer but had to be diligent in watching for delamination. If you are careful with marking and cutting lauan will give you a beautiful bright hull. The mahogany veneers look great with several coats of varnish or polyurethane. I have also used AC and BC plywood with good results. AC and BC refer to the grade of the veneers on the finish and back sides. One drawback to using lumberyard plywood is that you are limited to 8' sheets. Don't let this deter you. There are ways to make short sheets long. Scarfing and butt blocks are two ways. Scarfing simplified is gluing two edges together after having planed matching bevels on each piece. When you use butt blocks, you butt the two sheets together and use a smaller piece of the same material to span the glue joint. Glued and fastened with nails, screws, or even staples, the butt block is an acceptable alternative to scarfing. You can clearly see the butt blocks just aft of the bow seat in the photo of the flat bottom plywood skiff. Longer sheets of plywood are available but the price gets up there. Specialty lumber outlets will caryy this longer plywood.
        When it comes to the non-plywood pieces, once again lumberyard lumber will save you many dollars. Many of the plans for plywood boats that I have seen simplify things for the builder by calling out nominal sized materials. This means that you can go to your local lumberyard and get 1x and 2x stock. This means that a 1"x2" will actually measure ¾"x1 1/2". If you have purchased any lumber at all from a lumberyard or home center you know what I'm saying here.  If the plans do call for full dimension material there are still yards that carry it.  You can also double the members to make them slightly oversized. Be sure to use good waterproof adhesive and corrosion resistant fasteners.
        If you have your heart set on that fancy veneer plywood like you see on those canoe and kayak web sites or books of plans, there are sources. Instead of trying to list them here I would suggest finding where the fancy web sites get theirs, or looking in the classifieds in WoodenBoat magazine. Keep in mind that just because the designer calls for one species of wood, you have the option of using another species that is more pleasing to you. But also be warned that the designer may have called for a specific species for rot resistance or structural integrity. Again, do your homework.
        Wood for trim can be almost anything you like. Keep in mind that using softwoods for rub rails means you need to be a little more careful coming alongside a dock or when you flip the boat over onto the carry racks on top of your car or truck. Hardwoods take the abuse a little better and the contrast in colors can make an excellent design statement. Attaching oarlocks or thole pins will be another concern. Screws used to attach hardware need to get a good bite and the hardware needs to be well bedded to keep water out.

Wood Strip Construction

When it comes to wood-strip construction, wood matters. The majority of wood-strip boats that I have seen have been bright finished. This means the wood is seen under several coats of varnish or polyurethane. Again, I've simplified things. Wood strip hulls are built using thin strips of wood glued edge to edge, smoothed out, then sheathed with fiberglass cloth and epoxy, or as a less expensive alternative, polyester resin. Because you can see the full grain of the wood strips this is an area you where you don't want to skimp. I have seen many different types of wood used in wood-strip construction. By and far, the wood used most often is either red cedar or eastern white cedar. Inlays and accent stripes can be added to the hull layup. That piece of curly maple might look great in the hull as an accent, but when it comes time to smooth up the hull the surrounding soft wood will sand away much quicker than the maple. Just because the boat you want to build is over 16' you don't need to buy the longest material they make. As long as you stagger the joints in the planking you can use shorter, less pricey lengths. The easiest way to estimate the number of boards you will need to mill the strips is to measure around the widest mold where you will be attaching the planking. If, for example, your measurement is 55", that means approximately 55 strips. I always add 15% extra because the strips will already be only ¾" wide, plus with the bead and cove edges this width shrinks to about 5/8" wide. Figure on three plank strips per inch of board width.  If you are careful, this will also cover mistakes. I always look for flat grain boards to rip into my plank strips. Once the planks are ripped on the table saw the strips are now vertical grained. I have also used vertical grain boards and the color and grain patterns in the finished hull can be quite dramatic. Be careful when smoothing the hull while using flat grain strips when you plane the joints in the planking. Working against the grain can not only produce chatter marks, but can also lift a grain 'feather' making further smoothing harder. 
        Once you've decided on the type of hull material you want, it's time to consider milling the wood into strips. Most plans call for strips that are ¾" wide by ¼" thick. If you already own the tools you can mill the strips yourself. I can mill the strips for a 16'canoe in just over 4 hours. This includes ripping the strips on a table saw then adding the bead and cove edges on a router table. There are also sources where you can buy the wood strips ready to use. Having never purchased these machined strips myself I can't really quote a price. Many of the sites selling plans will also sell wood strips. With all of the types of wood available, I won't even try to get into what to use here.
The types of wood you will use for trim in plywood construction can also be used in wood-strip construction. The designer may suggest a species of wood for particular parts of the design. Again, use good judgment if making changes away from what the designer specified.
        One last thing to consider when it comes to wood is a kit boat. There are many great kits out there that are perfect for the beginner. Plywood kits come with pre-cut parts ready to glue together. Kits requiring molds will also have the material for molds supplied or even the molds themselves cut out. In wood-strip kits, many come with the molds either pre-cut or ready to cut. The wood strips have been milled and the bead and cove edges machined. There will be some cuts to be made by the builder but again, not having purchased a kit I can't speak to this point.

Non-Wood Materials

        I've mentioned before the use of lumberyard materials in building a boat. There comes a point where you will have to find a different source for certain non-wood items. Glue is not a serious concern. Basic yellow carpenter's glue can be used in some areas, and this can be found at your local lumberyard or home center. I don't spend the extra for water resistant yellow glue because in most cases the wood will be sealed under a coat of epoxy sealer, or at the very least good quality paint. Many other glue jobs will require epoxy or other special adhesives. The way I see it, it's like this: if you're going to use epoxy for taping joints on plywood boats or for sheathing the hull on a canoe, you might as well use it for gluing what has to be glued here too. Stem laminations, breast hooks, frame members, all become structurally stronger with epoxy as the adhesive. There are several types of epoxy resins and hardeners on the market, and add to that the numerous additives and it gets confusing fast. Here is where doing your homework pays off. Probably the two most popular are WEST System and MAS. I have used both and like each. Both are easy to use with both the metering dispensing pumps and additives. The difference I've found is cost. Where I live WEST System is carried by several better lumberyards and marine supply stores. I guess I paid a little more for this convenience. MAS  is somewhat cheaper but I have to order it on-line or through a local marine supply store. Buying in a larger quantity saved me the shipping cost where the supplier paid that cost. Sometimes you can order on-line and have it shipped to your local store saving the shipping cost. Do your homework.
Epoxies are two part adhesives and this limits the open or working time you have after mixing. READ ALL OF THE DIRECTIONS AND WARNINGS. The manufacturer of the epoxy you choose will supply any and all information you might want. I won't get into the use of epoxies because there are many sources describing the use.
        If you've done any body work on your car or seen it done you will be familiar with polyester resin. It is quite a bit cheaper to buy, but you pay a price in the ease of use, or lack of ease. Adhesion, or lack of adhesion to wood is the biggest reason I switched to epoxy. Add to that the health concerns. Sensitivity is just one of many concerns when you use polyester resin. Grab a handful of pink insulation and rub it on your skin. See what I mean. I won't even go into the styrene, MEK-P, and other wonderful chemicals. I'm not saying that epoxy is hazard free, but the hazards are far fewer. Your choice. Cost vs. health and adhesion, especially with oily woods.
        Fasteners are next on the list. Drywall screws are great, but not in a boat. Even if buried under epoxy putty or wood plugs. Steel rusts. Stainless steel or bronze are the way to go. Ring shank nails are great and can be found almost anywhere. These look similar to those little nails you use to put up wall paneling.  If your local supplier can't get them they can be found on-line. I have used both bronze and stainless and usually stay with stainless because of cost. Ring nails and epoxy are an incredible combination. Screws are the same. Stainless or bronze. Bronze may have to be sourced on-line if you live away from a marine supply store. Avoid using brass screws unless you really want that look. Structurally, they are weak and they need well sized pilot holes when being driven into any wood. This isn't to say that you don't need pilot holes for stainless or bronze. With brass it seems you just look at them funny and the head snaps off.

Fiberglass tape and cloth is something you will use plenty of. Avoid special deals from industrial distributors if they can't guarantee their cloth is compatible with epoxies or polyester resins. I'm lucky enough to buy mine locally but marine supply dealers on-line will carry it as well as those web sites that sell the fancy canoes and kayaks. The plans you use will dictate what weight cloth or what width tape to use. Cloth comes in many weights like 4oz, 6oz, etc. This means ounces per yard. I use 6oz for just about everything. It's worth the extra cost to buy the widest width cloth you can just to avoid sanding overlaps or seams. Tape width is self explanatory. Often you will use several widths of tape overlapping to build up a strong joint. This is mostly where bulkheads or frames meet the hull, or the deck of a kayak meets the hull.
         There are a large number of brushes and squeegees that can be used in wetting out fiberglass cloth so I won't go into that here. All of the manufacturers of the epoxies and polyester resins will also sell these items or at least make a recommendation.
        Hardware used to finish out the hull comes in many materials. Just like screws and nails you want to avoid steel. Oarlocks and oarlock sockets are probably the first things that come to mind. Look at catalogs and make your own decision. If you are anywhere near salt water, go with the bronze. I have used chrome over zinc with some success but I pay a tradeoff for the cheaper price with a shorter life. If you've taken the time to make a beautiful boat don't scrimp when it comes to the final details. I have had good success using the black plastic deck cleats and eye straps on my kayak decks. I had used them previously on my work skiffs and they held up to just about everything I threw at them. Keep in mind that I was also dock building at the time and was towing 1000lb plus floats across open water. 
        Oars and paddles are another choice. I have both ash and painted oars and like both. They both need yearly maintenance. Paddles are a personal choice. I can't remember the last time I bought a paddle. I have head great success making my own from ash, spruce, and even pine. The one thing I was sure to do was thoroughly seal the wood with epoxy. After that I used either varnish or oil based polyurethane.
        Epoxy in itself gives you a beautiful finish and it's all you need if your boat will never see sunlight. UV radiation will eat the epoxy finish if left unprotected. For years I used nothing but real spar varnish. But with the new VOC environmental laws the quality of real varnish just hasn't been the same. Maybe I need to be a little less frugal and spend the big bucks on the fancy stuff. Instead, I have gone to using oil based polyurethane. While the gloss finish isn't quite the same as varnish, the cost makes the difference. Protection is what we're after. Read and follow the directions for use and clean-up.
        Paint has caused more arguments among boat owners than you can shake a stick at. There are many marine finishes out there and it will take some homework to learn the pros and cons of each. I have used Petit and Interlux paints with great results. That's when I wanted to spend the money. When I had work boats I used oil based porch and deck polyurethanes. They are tough and come in many colors. I'll even confess right here that I have used latex house paint on one boat I had and it worked great. Purists are probably cringing about now. If you're like me and would rather use the boat than work on it, go with what makes you happy. I do all my fitting-out in the spring and do nothing but enjoy the boat all season. This isn't to say that I don't maintain things. An occasional bath and touch-up on the brightwork as needed are quick fixes. I really love the looks on peoples' faces when I drag a wood-strip kayak over the banking as if I were intentionally destroying it. I later explain that wood-strip boats are very rugged and easily repaired IF they do get damaged.

        Lastly, you've just poured some serious money into building your boat so don't cheap out of the carrying rack for your car or truck. This goes for a trailer too. Nothing like towing a $4000 boat on a $100 trailer. This goes for running rope through door openings or windows after setting the canoe on a blanket atop your car.

Tools and Shop Space

        When I started boat building I believe I had the minimum homeowner tools; electric drill, hand saw, saber saw, and circular saw. I also had a couple of try squares and a framing square. I managed to build a pretty good boat even if I had to borrow a plane and some clamps to finish a few things.
        Here's a short list of what I feel I need to build either a plywood or wood-strip boat:

Cordless or corded drill with bits
Countersink bits
Japanese pull saw
Try squares, one 12" and one 6"
Framing square
2' level
4' level is helpful
Staple gun
Chalk line
Roll of string
Bevel guage
Block plane
Utility knife
Random orbit sander
Shop Vac
Hearing protection
Safety glasses
Cartridge type respirator
C-clamps- as many as you can get
Quick Clamps
Moaning chair

Nice tools to have:

Table saw
Band saw
Stationary combination belt/disk sander
Router table with router
Router bits

I'm sure I'm missing something here but you can always do what I do when I need a tool: borrow or buy it.

 I mentioned a moaning chair here and elsewhere in this article. Some of you may have caught on to what I mean. A moaning chair is a really essential tool in the shop. Picture this: you've glued up some beautiful pieces of cherry for a canoe deck and have had it sitting on the bench curing for the last 24 hours. You go to check on it and realize you've glued the wrong side of one piece up instead of down. Too late. The epoxy has cured and now what. You drop into your moaning chair and start to think of what to do now. The moaning chair can also be used to sight down a hull while you smooth things up. Getting down low to eyeball things and be comfortable at the same time. You need a moaning chair.
        Clamps are another thing. Get as many as you can get your hands on. If your budget is tight here's a good substitute for light duty clamping: get a couple of feet of schedule 40 PVC pipe, 2". Cut 1" thick slices to make as many rings as you can. Once you have the rings cut go ahead and cut the rings down the side so they open like a C. These cheap clamps will apply considerable force and I have found I can use them for work on two hulls before I toss them.
        Here is one instance where I will recommend using drywall screws. In wood-strip planking, especially where you don't want to use staples to hold the planks, you can use wedges and feathers. I take two pieces of scrap hull planking, about 4" long, lay one atop the other, then drill a hole through the two about halfway down the length. Here's where you will use the drywall screw: slip a flat washer down the screw then screw down through the two pieces so they move like a propeller. When you need a little help holding a plank down to the mold and up against the previously installed plank screw the pair about ½" away from where the next strip will go on, into the mold not the previous strip. Now you can turn the top strip of the pair as a toggle to hold down the strip being installed against the mold then snug the screw. The scrap that is on the bottom is now the wedge. Use another piece of scrap planking cut to a wedge shape. Slip this under the 'toggle' piece and up against the wedge piece. This will apply a spreading force to the plank strip being installed up against the previously installed plank. These hold down jigs can be used over and over until the wood just falls apart. You'll want at least ten of these. Read this again and it will make sense.
        Here's another jig I use. I take pieces of ½" plywood cut to 3"x5" rectangles. From these rectangles I cut out a chunk along one of the 3" edges so the piece resembles an elongated C. I once again use a drywall screw in one of the legs of the C and screw it into the flat face of the mold where I need pressure. Now I can rotate the C enough to slip in two to three plank strips then slide another wedge as I described before to put force against the hull mold. Here's what you should be picturing: Standing alongside the building strongback you can see the edges of the plywood molds. When I say screw to the flat side of the mold I mean the side where you traced out the mold shapes onto the plywood. Got IT? Now, the two piece hold down jigs I described earlier you want to screw these into the edge of the plywood mold. Ted Moores' books Kayakcraft and Canoecraft show these jigs in use.

Shop space doesn't have to be fancy but it needs to be weather tight. If you plan to build over the winter where it gets cold, then you will also need heat. Keep in mind that if you build indoors in a living space, you will be using some type of chemical be it a glue or paint and it will stink. Something to keep in mind.
Floor space is important too. You should have at least two feet at either end of the building mold or hull itself plus several feet along each side. I have built a few canoes in my garage where I had to wheel the strongback out after I opened the door just so I could attach hull plank strips and have them extend beyond the end of the hull. I was lucky because I knew where the high and low spots were in my floor and could move the strongback there each time keeping it level. If you are lucky enough to be working on a wooden floor you can level and plumb the strongback or building platform then screw it to the floor to keep it that way.
        Having a warm space is important in gluing and using epoxy. Think before using any heating device that uses an open flame.

        A quick note on safety: before using any power tools, read and understand all directions and warnings. The same holds true for any chemical you may use to build the boat. Safety glasses and hearing protection are a must. I hook my random orbit sander to my shop vac and it draws away around 95% of the sanding dust. Investing in a cartridge filter respirator for using epoxy is money well spent.

Just as a last comment on tools and shop space. If you don't need a specific tool and maybe won't use it ever again, try borrowing it or renting it. When it comes to shop space, maybe a friend with usable space might want to build his own boat too. Offer to help him with his in exchange for the use of his shop space. I've seen this happen often. More people have started building their own boats after seeing another friend building one and that has started a domino effect. You might consider getting a small group together and renting a space short term. There are often people who just aren't ready to build their own boat but would like to help others while gaining experience. Maybe they could help by providing work space. Enough said.

        I hope that after reading this you aren't even more confused than when you started. I have learned all of this through personal experience, reading all I can about boat building and design, and from paying attention to experienced builders. A teacher told me many years ago that the only stupid question is the one you don't ask.

About the Author

While I am not a professional builder I have built a number of canoes and plywood boats for paying customers. The large majority of these customers were people I knew or were recommended to me by other people I knew. Until I can truly get set up as a business to build full time I will continue to take small jobs when I can.
The name
Wood…Water…Happiness comes from the personal philosophy of mine. Wooden boats, being on the water as often as I can, and drawing happiness through the building and use of beautiful wood boats. I look at building a wooden boat as a form of therapy. Running my hands over the hull when I smooth the planks, eying the sweet lines of the hull taking shape, the smell of the wood be it cedar, pine, or other aromatic wood. I don't see it as work because I can spend 16 hours a day easily in the shop and time goes by in a flash.
        I'm always willing to talk about wooden boats, so if you would like to ask me a question or send me a comment you can reach me at
laxreff@msn.com <mailto:laxreff@msn.com>.
I hope to have my web site up and running soon and when it is you will be able to get the address here at this site.



Build the New Instant Boats
Harold "Dynamite" Payson
International Marine/Ragged Mountain Press
ISBN 0-07-155966-3

Jennifer andTed Moores
WoodenBoat Publications

Ted Moores and Merilyn Mohr
Firefly Books Ltd.
ISBN 1-55209-342-5

Allan H. Vaitses
ISBN  0-937822-55-8

Rip, Strip, & Row
A builder's Guide to the Cosine Wherry

J.D. Brown
Tamal Vista Publications
ISBN 0-917436-02-4

Boats with an Open Mind
Philip C. Bolger
International Marine
ISBN 0-07-006376-1

WoodenBoat Magazine

The books I've listed above can all be found at the WoodenBoat Store.
www.WoodenBoat.com http://www.WoodenBoat.com
Non-Wood Items

West Marine

www.westmarine.com http://www.westmarine.com
Fasteners, paint, adhesives, rigging supplies

Hamilton Marine

www.hamiltonmarine.com http://www.hamiltonmarine.com
Fasteners, paint, adhesives, rigging supplies

MAS Epoxy

www.MASepoxy.com http://www.MASepoxy.com
Epoxy resins, fillers, fiberglass cloth, application tools

WEST System Epoxy

www.westsystem.com http://www.westsystem.com
Epoxy resins, fillers, fiberglass cloth, application tools

Bear Mountain Boats

www.bearmountainboats.com http://www.bearmountainboats.com
Plans, kits, building supplies

Chesapeake Light Craft

www.clcboats.com http://www.clc.com
Plans, kits, building supplies

Pygmy Boats Inc.

www.pygmyboats.com http://www.pygmyboats.com
Plans, kits, building supplies
Copyright 2009 DIY Ballistics
Backyard Boat Building (Page 2)
By Dan Gosselin