Monday, October 13, 2014

Building a 1/12th scale canoe

     OK!  This is the process I go through to build a one inch scale canoe.  This particular project will be a 16 footer in one inch scale, made of cherry wood.  It will be a "plank on frame" construction, using 1/16" x 3/32" strips of cherry wood.

     I start with a jig I made for the basic shape and size of the boat I want to make.  I call it a "strongback".  The strongback pictured is for the 1/12th scale, 16 footer I'm making now.   I also have jigs for a one inch scale 12 foot canoe, and for two different types of rowboats I like to build.  The base of the strongback is made of very strong apitong wood, and the forms are made of basswood.  I reinforced the forms with a triangle wedge for strength.  The middle form is the widest, the 2nd and 4th forms are the same size, as are the end forms.  There is a notch in each, on both sides, where the first plank for both sides rests.  A lot of tension is put on this strongback while planking the canoe, so it must be able to withstand this pressure.  The canoe is built upside-down with this type of construction.

The first pieces of the canoe are called "stems".  I cut out a piece of paper and trace it on a piece of 1/8 inch thick cherry wood.  I'll need two of these.  One for each end of the canoe.

I cut out the stems using a jewelers saw with a very fine blade, as close to my pencil marks as I can.  After it is roughly cut out, I use my Dremel to sand the pieces to the exact shape.

Here are the two finished stems, ready to glue to the strongback.

I use two types of glue for building boats.  The main glue I use is slow setting CA.  (Cyanoacrylate, super-glue type adhesive).  I like the "Loctite Gel Control" type, as it gives you a bit of time to align the parts where they need to be, before they set permanently.  Here, I have glued the stems in their pre-determined location, at each end of the strongback.  I put a shim underneath each stem, to make removal easier once the canoe is done being planked.  I make sure the top of the stem is exactly 1/16" above the upper edge of the forms, because this is where the bottom plank goes, and it needs to rest on top of them.

The next step is to install the bottom plank to the ends of the stems.  It is VERY important to glue this plank on straight, and to LIGHTLY glue it to all the forms below it.  I leave the ends roughly cut, and will sand them smooth later.

Now comes the fun part!  Planking!  Each plank must be beveled to the correct angle on each end before it is glued to the stems.  I usually bevel one end, and glue it in place like this: