The Deck

Building the deck has two major steps. The first is to set up the shape of the deck by bending the gunwales into place. Once bent into place, the shape is locked in by the end blocks. They are temporarily nailed into place. Symmetry of the deck is checked and then end the blocks are doweled. The shape of the deck is now firmly established and becomes the form for determining the width of the deck beams. The deck beams on either end of the cockpit are installed first. They are both the same elevation. Once in Place, the elevations of the remaining deck beams are established. Knowing the height and width of our remaining deck beams we can construct them. Deck beams are temporarily nailed in place as they are constructed. Once all of them are in place, they are doweled. Then the deck beams as well as the end blocks are lashed.

A brief note on terminology here. The use of the term end blocks might seem unfortunate since the term block in a nautical context usually refers to a pulley. Still, I couldn't come up with any better terminology. What I call end blocks might be called breast hooks in a boat where the gunwales actually come together at the ends. But in an iqyax^, the bow and stern extend beyond the ends of the gunwales so that the end blocks don't quite meet the requirements of the definition.

There are 7 deck beams, DB1 though DB7 in the drawing. Three of these deck beams have a special function. DB4 is the front deck beam support. DB5 is the rear deck beam support and back rest and Db3 is the foot rest or foot brace. The bow block and stern block are wide versions of deck beams but are not generally referred to as deck beams. Part of the reason is historical, namely, that the bow and stern blocks were extensions of the ends of the gunwales and not separate components like the other deck beams.

Shaping the Deck

The shape of the deck is defined by its width in the middle and the widths at the bow and stern. In our case, the width in the center is 24 inches. The width at the bow is 6 inches. The width at the stern is 10 inches.

The gunwales are bent into shape with the aid of three sticks, some nails and two pieces of rope that hold them in the desired configuration. I am partial to a simple approach, that is, three sticks cut to length. You can get more elaborate and make more complex forms if you like. The simple approach works best if you have good lumber. If the two gunwales aren't exactly matched in flex then you might benefit from more elaborate forms that do a better job of forcing the gunwales into the right shape.

The drawing above also shows an auxilliary spreader near the bow. This spreader may or may not be needed. If the curve of the gunwales near the bow looks good, you won't need it. But sometimes, the gunwales near the bow look a little flat and then, widening the space between them by maybe half an inch will give them a more pleasing line. The amount of curvature in the gunwales is a function of both the length of the gunwales and the amount of separation in the center. A wider or shorter deck makes for more curvature while a narrower or longer deck makes for less curvature. Flatness of the gunwales near the bow is usually more apparent in long narrow boats.

Start by cutting the spreaders. The length of the center one is 1-1/2 inches less than the beam, in our case, a 22-1/2 inch spreader for a 24 inch beam. Cut the ends at a 10 degree angle.

The two end spreaders are simply cut to length, 6 inches for the bow and 10 inches for the stern.

Nail the end spreaders to the ends of the gunwales with some 4d or 5d finishing nails. Your gunwales at the bow and stern should now be separated by 6 and 10 inches respectively.

Loop some heavy string or light rope loosely around the gunwales near the end. This will keep the end spreaders from popping loose when you insert the center spreader. Now insert the center spreader. The center spreader should line up with the center marks at the tops of the gunwales. If the ropes at the ends are too tight and the sides of the gunwales are pinched in, loosen the ropes till you don't see any more pinching.

Nail the center spreader to the gunwales with two 4d or 5d finishing nails on each side. Leave a bit of the nail head sticking out to make pulling them easier later on.

When you're all done, your deck will look something like the one in the picture above though probably longer and more symmetrical. As you can see, the gunwale on the right is stiffer and more straight than the one on the left. If your deck looks like this, don't worry. When you install the bow and stern blocks the gunwales will be forced into a more symmetrical configuration.

Bow and Stern Block Installation

Now that you have bent the gunwales roughly into shape, it is time to make the gunwales completely symmetrical and lock that shape in place by installing the bow and stern blocks. The bow and stern blocks join the ends of the gunwales to each other at their respective ends. You want to take some care with constructing them since they are critical to making the deck symmetrical. The sides of the bow and stern blocks are cut at a compound angle. The angle in the horizontal plane matches the angle that the gunwales make with each other. The angle in the vertical plane is 10 degrees.

Cutting the Bow Block

You can fabricate the bow block from a 1-1/2 inch thick piece of wood into which you cut a 3/4 inch deep channel.

Or you can build it up from some 3/4 inch thick pieces. The photo above shows the built up pieces being doweled and glued. Which method you choose depends on what kinds of tools you have handy.

Start with a piece of wood that is 5-1/2 inches wide and either 3/4 inch or 1-1/2 inches thick.

Lay your piece of wood across the gunwales 1-1/2 inches back of the bow. When you have it aligned with the marks on the top of the gunwales, run a pencil on the underside of the two by six along the top inside edge of your gunwales.

You now have two pencil lines on your piece of wood. These are represented by the two dashed lines in the drawing. Use a sliding bevel to check that both lines make the same angle with the edge of the two by six. If they don't, split the difference between the two angles and draw two new lines that make the same angle. These are represented by the two solid lines in the drawing.

Find the distance halfway between the two angled lines and draw a center line between them. Run the center line all around your block of wood. The face with the angled lines will be the top face of your bow block

If you are working with a 1-1/2 inch thick piece of wood you will want to cut the channel down the center of the bottom face before you trim off the sides. The dimensions of the channel are shown on the figure above. It is critical that the channel is centered since it lines up the top of the deck with the bow assembly. If the channel is off center, the bow end of the keelson will be thrown off center and you don't want that.

If you are working with 3/4 inch thick wood, you will want to build up wood on the underside of the top piece to form the channel.

Once you have cut the groove on the bottom of the bow block, trim the sides.

Cutting the Stern Block

The stern block overhangs the ends of the gunwales by an inch. Line up you two by six stock on top of the gunwales and mark the underside of it where it intersects the upper inside edge of the gunwales. As with the bow block, even up the two angles if they are not the same.

Run a center line between the two angled lines and run it all around the piece of wood.

As with the bow block, you will need to cut a groove down the center of the bottom face of the stern block. See the drawing for dimensions. The groove only needs to go about two inches into the block but if you are using a table saw to cut it, it is easier to run it all the way across the bottom of the block.

You can now cut the sides of the stern block.

Rounding off the rear edge of the stern block completes its construction. If you have a helper, you can use a thin flexible piece of wood to spring a curve along which to trace the curve. Use a plane or a jig saw to trim off the excess wood.

Install the bow and stern blocks

We will be doweling and lashing the bow and stern blocks in place. But before we do that, we will temporarily nail them in place to assure that they are properly aligned before we drill doweling holes. Good alignment is critical since this is what will assure symmetry of the deck.

Temporarily nail the bow block in place

This picture shows the placement of the temporary nails as well as the dowels. There are three dowels on each side. The center dowel goes straight in. The other two dowels go in at an angle to lock in the joint. You will be nailing the bow block to the gunwales before doweling. If you place the nails as shown, you will not have to pull them before drilling the doweling holes.

Align the bow block with the marks on the upper edge of the gunwales at the bow. It will be sitting 1.5 inches back of the front of the gunwales. Use two 4d nails on each side to nail the bow block in place. You can probably manage this procedure by yourself, but if you keep the block aligned while someone else does the nailing, it will go a lot easier. Remember to not bury the nails but leave 1/4 of an inch sticking out so you can pull the nails later.

Temporarily nail the stern block in place

Align the stern block with its marks on the gunwales and use four 4d nails to temporarily nail it in place. Remember to leave the heads of the nails sticking out.

Check Deck Alignment

Now it's time to step back and sight down the deck to make sure it looks symmetrical. If it doesn't, the alignment between your blocks and gunwales are probably off. If it is only slightly off, you can probably tap the errant parts in place with a hammer.

Also check that the sides of the gunwales mate up flush with the sides of the blocks and that there are no gaps between them.

Some Notes on Doweling

All the doweling on the deck will be done with two inch long 1/4 inch diameter hard wood dowels. Dowels will be driven into 15/64 inch diameter holes. The fact that the holes are slightly smaller than the dowels will assure that the dowels fit snugly. There is no need to glue the dowels. The lack of glue allows the joined parts a slight amount of movement which is part of the overall scheme of having no rigidly fixed joints.

You can of course carve your own dowels, but the easiest way to make them is to cut them from a longer rod.

There is no need to saw the dowels off, you can simply roll a knife edge over the rod and snap off the dowels.

The dowel holes are made with a 15/64 inch drill. A piece of tape wrapped around the drill bit 2 inches from its tip acts as a depth gage. No need to be overly concerned about accuracy here. If a dowel is a bit too long for the hole, you can trim it off later.

Dowel the Bow and Stern Blocks

Now that you have assured yourself of good alignment between the blocks and the gunwales, you are ready to dowel them. If you located the nails judiciously, you will be able to drill doweling holes without pulling the nails first. Resist the temptation to drill all the holes at once. Drill one hole, drive a dowel and then pull a nail before drilling the next hole. The first hole drilled is the most critcal since it will lock in the position and angle all at the same time, so be sure to check one last time that the block lines up with the marks on the gunwale and that there are no gaps between block and gunwale faces.

When you are done with the dowels, make sure all the nails are pulled. If you accidentally buried one of the nails, figure out a way to get it out. A needle nose pliers works for this purpose. If you leave a nail behind, it will rust and expand, cracking the wood and generally hastening the deterioration of the wood around it.

Deck Beam Elevation

Deck beams in the iqyax^ are arched. They give strenght to the deck and maintain the shape of the deck by bracing against the gunwales. Deck beams also support the deck stringers. Deck beam 4 and deck beam 5, the two deck beams on either end of the cockpit are the tallest deck beams and both rise 2-1/2 inches above the gunwales. The remaining deck beams rise up to support the deck stringers that are supported at one end by deck beams 4 and 5 and at the other end by the end blocks.

The relationship between the deck beams and the deck stringers in the Atkan iqyax^ is shown in the drawing above. The deck stringers slope downward toward the ends of the boat so that the deck beams get progressively lower toward the ends. The deck stringers are notched at deck beams 3, 4, 5 and 6. This locks them into the deck beams at those positions. The deck stringer are left to float at the remaining deck beam intersections. You can build your deck in this way or you can skip the notching of the deck stringers and simply have them sloping downhill in a uniform manner. If you skip the notching, your deck stringers will have a little more opportunity to move.

We will install deck beams 4 and 5, the deck beams on either end of the cockpit first and then figure out how tall the remaining deck beams need to be. The drawing above shows the geometry of the iqyax in the vicinity of the cockpit in cross section. The deck beam rises 2-1/2 inches above the tops of the gunwales. The bottom most edge of the deck beams drop 1 inch below the top edge of the gunwales. This gives the deck beams a total elevation of 3-1/2 inches. The critical dimension from the standpoint of the paddler is the inside space which works out to 7-1/2 inches. Making deck beams taller would give the paddler more room but would also raise the deck and make paddling more difficult. The longer your cockpit is, the less of an issue internal space becomes, at least as far as your ability to fit into the boat is concerned. It still will impact your ability to carry gear. But you won't have to be as concerned about whether your thighs fit.

Install the Deck Beams

At this point, the ends of your deck are fixed and the center spreader is still in place. You are now ready to start cutting and installing deck beams.

Deck beam installation progresses in three passes. On the first pass, we trial nail all the deck beams in place. On the second pass, we dowel the deck beams to the gunwales and pull the nails. On the third pass, we lash each of the deck beams to the gunwales.

Deck Beam Layout

Deck Beams on an iqyax^ are arched to provide more internal space than flat deck beams would provide. The two deck beams on either end of the cockpit are the same height and the tallest. The remaining deck beams get gradually lower toward the ends of the boat. All the deck beams can be cut from two by four construction lumber. Although each deck beam has a different shape, the scheme for laying them out is the same for all the deck beams.

Start the layout process by figuring out how long the deck beam needs to be. Find a section of two by four that is clear of knots and cut it to a length equal to the width across the gunwales at the place were it will be installed.

Place the piece of lumber on edge across the gunwales and with a pencil, mark the underside of it where it intersects the inside top edge of the gunwales. Make an arrow at the top edge of the two by four to indicate which direction is forward. The underside of your future deck beam will look like the picture above.

This is a picture of what the layout drawing of your deck beam will look like when it's all done. The deck beam will be 1-1/2 inches deep in the center and will taper down to 1 inch at the ends.

Bring the marks from the underside of your deck beam around to the front. Use a combination square to draw two vertical lines that define the ends of your deck beam. Run these lines up 1 inch from the bottom edge. Find the half-way point between these two vertical lines and draw a center line.

Draw a line for the top of the deck beam. The height of this line above the bottom edge of the wood equals the desired elevation of the deck beam plus 1 inch. Make a mark 2-1/2 inches on either side of the center line.

Draw another line parallel to the first one, 1-1/2 inches below the first one. Make a mark 1-1/2 inches on either side of the center.

Connect the marks on the top of the deck beam to the top marks at the ends of the deck beam.

Connect the marks on the underside of the deck beam to the marks at the ends of the deck beam.

Use a bevel gage to draw the 10 degree angle that the ends of the deck beam make with the vertical.

Bring the line you just drew around to the bottom edge of the deck beam. The line on the bottom defines the angle that the deck beam makes with the gunwales in the horizontal plane. The line on the face of the deck beam defines the angle that the deck beam makes with the gunwales in the vertical plane.

Cut the Deck Beam

Once you are finished marking the face of your two by four with the shape of the deck beam you are ready to cut it out. The trickiest cut is at the ends of the deck beam where you need to cut a compound angle, one angle to match the taper of the gunwales in the horizontal plane and a ten degree angle in the vertical plane. If you are using a hand saw to make this cut, cut out the shape of the deck beam first and then trim the ends. If you are trimming the ends of the deck beam on a table saw, then you are better off trimming the ends before cutting out the shape.

Regardless of how you cut the ends of the deck beam, make a slight allowance for the fact that when you marked the ends, the pencil lines will be slightly closer together than the spread of the gunwales due to the width of the pencil lead. The duller your pencil, the larger the offset will be. When you cut your first deck beam, cut it a little long and then you can see how much you need to adjust for marking errors.

Install Deck Beam 4

Deck beams 4 is the first to be installed. Deck beam 4 is near the center of the boat and if it turns out that your center spreader is in the same location as deck beam 4, move the spreader forward or back so that it does not block deck beam 4. Trial nail deck beam 4 in place using two 4d nails on each side of the gunwales. Leave the heads sticking out so that we can pull the nails later.

Deck beam 4 rises 2-1/2 inches above the gunwales.

Install Deck Beam 5

Like deck beam 4, deck beam 5 rises 2-1/2 inches above the gunwales. Install it as you did deck beam 4.

Your deck should now look something like the picture. The two end blocks are in place and deck beams 4 and 5 are in place as well as the center spreader.

Measure Elevations of Deck beams 1,2 and 3

With deck beam 4 in place, you are ready to measure the elevation of deck beams 1,2 and 3.

To do this, find a straight stick long enough to be supported by deck beam 4 in back and the bow block in front.

With the stick in place, elevate the front about 1/2 inch with a shim. Now measure how far the underside of the stick is above the top edge of the gunwales at each of the deck beam positions for deck beams 1, 2 and 3. Write the elevation down on top of the gunwale next to the deck beam location. Total elevation of your deck beam will be this measurement plus one inch to account for the depth that the ends of the deck beams sit below the top edge of the gunwales.

If you are going to notch the ends of your deck stringers at the cockpit, then you should also notch the end of the stick that you are using to measure deck beam elevations. Depth of the notch is 1/2 inch. Deckbeams 1, 2 and 3 will be a proportional amount less tall than if you didn't notch the measuring stick.

Measure elevations of deck beams 6 and 7

Measure elevations for deck beams 6 and 7 in the same manner as you did deck beams 1 - 3, only you don't need a shim under the measuring stick at the stern block.

Install Remaining Deck Beams

Once you have established elevations for the remaining deck beams you can cut and trial nail them in place. The order that you do this in doesn't matter much, although I tend to work from the center outward.

Sometimes you will find that you cut a deck beam either a little long or a little short. If it is too long, you can correct by trimming. If it is too short, you can shim it. Or you can move the deck beam slightly forward or back until it fits. However, deck beams 3, 4 and 5 need to be in exactly the right place. Deck beams 4 and 5 define the cockpit size and deck beam 3 is your foot rest.

Dowel Deck Beams to the Gunwales

Dowel each deck beam to the gunwales. Start in the center and work your way toward the ends.

Plane Sharp Edges

Before you start lashing, you will want to soften the edges of the gunwales by running a plane over them. A sixteenth inch off the edge is sufficient. If any dowels are sticking out of the gunwales, you will also want to trim them off and plane them flush.

Lash Bow and Stern Blocks and Deck Beams to the Gunwales

Lash bow and stern blocks and all the deck beams to the gunwales. Start in the center and work your way toward the ends. Lash both ends of one deck beam before proceeding to the next. Lashings come in two styles. Where the deck beam does not line up with a rib mortise, the lashing goes straight around the gunwale. Where the deck beam lines up with a rib mortise, the lashing is offset to one side so it doesn't cover up the rib mortise.

Four turns of string are sufficient for each lashing. Tie the lashing off on the underside of the deck.

Lashing Details

Drill a lashing hole about 2 inches in from the outer edge of the gunwales to avoid drilling through the dowels. The diameter of the hole is 3/16th of an inch. Looks like those dowels still need cleaning up before any lashing starts.

Carve a notch both at the top and bottom of the gunwales for the lashings to sit in.

This is what the notch looks like. If you're ambitious, you can also countersink the lashing hole just a little to make the edges less sharp.

This much string, about 3 feet is plenty for a lashing. I like to not use a measuring tape for this kind of thing.

If your string is nylon, like mine is, you want to cut it by melting it off. If you cut it with a knife or scissors, it will unravel.

Wax the string by pulling it over a small cake of wax. The wax makes the string more sticky and makes it easier to maintain tension in your lashings. If you can find waxed string, you can skip this step.

Make a loop in one end of the string. Keep the loop small.

You will need a lashing needle, a bent over piece of wire, to feed the string through the lashing hole.

Feed the string into the hole from the underside so that the loop ends up on the underside of the deck. Run the string through the loop and reverse directions. Run the string around its path about 4 times or until you cannot get the needle through the hole any more or until you only have enough string left to tie it off.

Tie off the end of the lashing with a series of half hitches.

Melt off excess string. Leave about an inch of tail sticking out.

If your deck beam lines up with a rib mortise, run the lashing off to one side as shown here to avoid lashing over the rib mortise. You will need to drill an extra lashing hole in the gunwales for this kind of lashing.

Here's another view of this lashing.

Cut the Bow Notch

The bow ends of the gunwales need to be notched to support the bow plate.

The notch should be 3/4 inches down from the top inside edges of the gunwales and right up to the front edge of the bow block.

If you have a saw that is long enough to span both gunwales, you can cut both notches at once. If the notches are a different depth, your bow plate will not sit level, but that can be fixed with shiming or trimming later on.

Paint the Deck

You can hold off painting until the whole frame is finished, but painting the deck now is easier than later when you have to reach through the ribs to get at the underside of the deck beams.