First Cuts

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Much has been done so far. Tools and supplies are purchased.  The plan is complete.  The boat platform is built.  All the lofting lines are drawn.  It is time to start cutting and joining.  In this chapter we will cut the bottom part; draw the keel; cut the keel; and join the keel to the bottom.

Supplies needed:

  • A jigsaw: I prefer a cordless for some tasks and a corded for either.  Either works for any task.
  • Ear plugs and safety goggles
  • A pencil
  • A carpenter’s square
  • Scrap wood: small bits and a long, flimsy piece
  • 3-4 clamps
  • The 6′ x 1″ x 6″ pine board
  • Your pre-lofted plywood sheet

If you have not used a jigsaw before, practice.  Draw lines on wood and cut them.  It doesn’t matter what you make.  Practice cutting inch-thick pine.  Practice cutting quarter-inch plywood.  Like riding a bike or playing the piano, quality jigsaw use requires muscle memory.  I can offer only five points of written advice:

  1. Pay attention to where the blade is and obey all safety instructions.
  2. Let the saw do the work.  Don’t press it against the wood.
  3. Control the saw from the back.
  4. A moving saw doesn’t steer right away.  It’s like a boat or an airplane: not a car. Steer the saw in the direction it will go, not the direction it is going.
  5. Use the appropriate blade.  Some blades cut strait lines.  Others are for curves.  Some cut metal, some cut plastic, and some cut wood.  Some blades make rough cuts. Some make fine cuts.

Other than that, good cutting depends on your hands and arms.

Let’s get to work.  Choose a curve to cut first and clamp the plywood onto the boat platform.  Make the the curve as close to the edge as possible without crossing it.  The closer it is, the less wobbly it will be.  At the same time, you don’t want to risk cutting into the boat platform.  Here I managed about an inch clearance for the blade, which worked out fine:

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… Yes, we had 8 inches of snow in early March.  That’s life in Western Wisconsin.

The jigsaw blade is for rough, strait cuts.  The loft line is a curve, but it is a big enough curve to look strait from a jigsaw blade’s perspective.  For 1/4″ plywood, my cheap cordless jigsaw has plenty of power.  When cutting, keep the edge of the blade along the outer edge of the pencil line.  If the saw wanders, steer it back gradually.  Abrupt turns look far worse than long, gradual turns.  In any case, this sheet will be sanded and it is hard to predict what the final shape will be once the strakes are added.  A 1/4″ could be sanded off.

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Clamp the sheet in two places for stability, then cut away.

Note the 1″ x 4″s we placed on the boat platform for lofting are no longer needed.  Only one corner of the plywood sheet needs to be stable.  The other corners can hang off the edge.  Also notice that my scrap came in four parts.  You could cut out two long C-shaped pieces of scrap.  I cut mine at the midpoint to avoid it snapping in half in my face.

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The keel is next.  A keel is the spine of a ship or boat.  In this design it provides structural strength and grips the water for better sailing. Many small sailboats have removable keels that you can sink a few feet into the water.  They allow a boat to sail into the wind and keep it stable.  My boats aren’t built to do that.  These are for cruising.  The bottom is wide and flat.  A stable fishing platform is more important to me than high speed.

But if you want a sinkable keel, go for it.  I’d be happy to see your design.

For this, you’ll need a carpenter’s square, three clamps and a flexible piece of scrap.  Here I used a piece of trim.  It’s longer than any scrap plywood I had on hand.  Step one in building our keel?  Find the center point.

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From that center point, mark 3″ away from the edge.  The keel will be 3″ tall.IMG_20170303_113110231.jpg

Go to the opposite edge of the 1″x6″.  At each corner, mark the 3″ point from the opposite edge.  This will make sense soon.

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Build a “crossbow”.  The middle meets the 3″ mark at the center of the 1″x6″.  The tips are at the corners of the 1″x6″.  To recap crossbow building, see the previous chapter on lofting.  IMG_20170303_113738035.jpg

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Trace the curve.  Then move the crossbow three inches.  The center should line up with the edge of the 1″ x 6″.  The tips of the crossbow should line up with the 3″ marks we drew on the sides.  Trace again.  The result is two curved lines that are parallel and exactly three inches apart.

Note the knot in the wood.  I partially avoided it, but construction adhesive will eventually fill in the gap.

Now cut it.  Brace the part at two points.  I used my more powerful corded jigsaw for this cut.  The cordless would have done the job, but not as quickly.  When using corded jigsaws, pay attention to where the cord is.  Cutting the cord and getting electrocuted is unlikely.  Snagging the cord and wondering why the jigsaw doesn’t move forward; that happens to me all the time.

This next step takes skill.  If you haven’t yet acquired skill, patience will do just fine.  Line up the keel along the center of the bottom part.  The tips of the keel should stick out past the tips of the bottom part.  Adjust each end of the keel so they stick out an equal distance; about an inch, in my case.  Then mark the spot where the tip of the bottom part overlaps the top of the keel.  This is not the tip of the bottom part.  This is about a quarter-inch away from that.

Also mark the tips of the bottom part at that point.  Then cut.tip

Then cut the keel.  If you measured correctly, both pieces should line up on both ends like so:

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If they don’t line up perfectly, don’t worry.  These edges will be covered in layers of wood, paint, and glue.

Now clamp the ends together and mark every six inches along the center line of the bottom part.  Starting from one tip and moving to the other, attach the keel to the bottom part using 1″ screws.  Take care here.  The screws must be as vertical as possible.  Otherwise, they poke out of the keel.

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If a screw pokes through, it’s not the end of the world.  Remove it and try again.  As you attach, check the keel for such pokes.IMG_20170303_144311254.jpg

When all screws are in, flip the boat over and inspect your work.

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This is starting to look like a boat!  Get ready to work on the ribs, the stem and the stern.

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