The 9.5 Laura Bay - Part 3
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design by Warren D. Messer - Seattle, Washington - USA

Part 1 - Part 2 - Part 3 - Part 4 - Part 5 - Part 6

Now that the eight side panels and the stern panel are all joined together to form the finished hull, the hardest part for me as a designer begins. I find it easy to work through the hull shaping process to arrive at the finished design. But I find it hard trying to figure out what I will do for the interior layout, or layouts. I've been coming up with several different ideas as to how the seats, bulkheads, and such should be arranged with each design. I try to make the designs appeal to the broadest segment of home builders as possible, but I'm finding that the more choices I come up with, the more choices I come up with.

The Laura Bay gave me a chance to build my movable center seat option as a way to balance out a small rowing boat with an uneven load distribution. I found while rowing the 8ft Nuthatch Pram, that the addition of an extra person in the stern seat makes the boat squat way too much in the stern with the standard side to side middle seat. A third person in the bow will counter this effect, but I wanted a better solution than always making sure you had an extra person around. I changed the middle seat in the Nuthatch to run fore and aft and it now makes a "T" with the bow seat. I added an extra set of oarlocks forward of the original set and now I only have to slide forward in the seat and move the oarlocks to the forward set of holders. The "T" seat also helped in locating the mast partner.

But when I did the calculations for the CLR and CE, the mast for the Laura Bay was farther aft of where I wanted the bow seat to stop. I could have used the "T" seat, but would have lost a lot of space (leg room and storage) in that area. I had thought about using a movable seat in the 12ft Nuthatch and had worked up some rough ideas about how to do this. I had also worked on a new idea about incorporating a centerboard trunk into that design too; which was a modification on the center seat pyramid I had used on the Hudson Springs Pram. When I saw where I had to locate the centerboard, and at least one bulkhead to support it, I decided on putting the movable seat in the Laura Bay. I added a pyramid centerboard trunk and designed a removable curved arch for the upper mast support. The center seat can be moved over a 12" range to balance the boat for rowing or left behind when sailing. If the wind dies while sailing, the centerboard pyramid makes a good seat to row home with.

With all the "why I did that" out of the way, we can get on with the rest of the story. There are three main things to help insure that everything goes in correctly. The first is that the hull is level and square. In Part Two, I went on about measuring from each corner to the bow to make sure the distance was the same. It doesn't matter what the distance is, just that they are the same. Remember, your boat may/will be different than mine through accumulated measuring differences, but just slightly. If you look at the photo in Story Two, you can see the two cords I used to pull the hull into alignment. They are attached to the upper bow tie wire and one goes to each upper corner tie wire. I tie a loop near the end of each cord and use that as my pulling point coming back from the bow tie wire. On this hull I only had to pull in on the Port cord to square up the boat.

The second thing is that you made some pencil marks at each of the one foot station marks along the edges of each of the hull panels. They are matched pairs and the station marks reference all the hull panels to each other. There will be some shifting of the station lines as the hull panels are wired together and bend into shape, but the line offsets will be mirror images of each other on each side. The lines will give you a visual reference when lining up the interior bulkheads and such.

The third thing to have done in the original lofting of the hull panels, was to have made small cuts on the "upper" edges of the top side panels at the station lines, with a hacksaw blade or equivalent. These cuts will now be used as fixed points to line up with and measure from in order to establish the positions for all the interior parts of the hull. They will make sure that things are square with the centerline of the hull. You also want the interior parts to be level, but you will have to find new attachment points for the leveling cords since the tie wires were removed during the taping process. We will level the boat again after installing the corner blocks.

The corner blocks are cut from the same material as the gunnel wood, unless you laminate up some other woods for color. I did this with the breasthook, by using some old scraps of oak and maple flooring I had laying about. One word of caution is to not cut all your hardwood into rail material. You will need blocks. Think ahead. I'm running at about 90% on this matter. I used a ¾" x 3" x 6" block for this. You have several angles coming together here, making cutting out the blocks a thinking game. There is the vertical angle of the stern panel, the vertical angle of the side panels and the horizontal angle between the stern to side panels. The stern angle is the same on both corner blocks, so I cut them at one time. Place a board across the tops of the side panels at the stern and measure the angle between it and the stern panel. Set your table saw and cut this angle.(its also listed in the plans, but still check it on your boat). Measure the angle between the board and one of the side panels (check both sides) and set the table saw to this new angle. I like to measure the horizontal angle between the side and stern panels and use this angle to set my sliding miter gage. I then make a test cut close to, but not on the finish line to check for errors. Then make the finial cut. Now reverse the angle in the miter gage and make the cut on the opposite end of the block. Now cut the block in half and you have your two corner blocks. You still have to square the forward outside corner of each block to 90 degrees with the new side panel edge to match up with the square aft ends of the inside gunnel rails. The full and study plan sets go into this and the placement of the blocks.

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The breasthook is a little more problematic in it's installation. In my plan sets I have a couple of different ways to fit it to the hull. With this Laura Bay, I made the center lamination longer than all the others so it would stick through a notch in the bow. It looks good, and gives a little extra meat to attach the outer rails to at the bow, but was a bear to cut the bevels to match the side panels, without cutting off the extended center lamination. If you have a tilting bandsaw this is no problem. Did I mention that both sides are continuous curves with a bevel. The easiest way would be to just level and screw the breasthook to the hull and fill the gaps with EZ-fillet and sand smooth. We're Duckworks, we don't do easy. Make up as many cardboard and wood templates as you need to get this part to fit. It is the visual focus point of the hull and sets the level of finish for the whole boat.

Now its time to level the hull again. Put a couple of screws in the corner blocks for the tie down cords or just loop them over the corners as in the photos. You will cut in the corners once the rails are installed. Level again at the middle and bow cross braces. Add screws as holding points or just loop around them. The cross braces stay in until the rails are installed.

Now comes the beard twiddling period where I walk around the hull again and again trying to figure out the real world heights of seats and such. My first design drawings are only a starting point, and may or may not be that accurate. I only know where the centerboard and the mast should be in relation to each other and to the hull. The mast will come later, so now the centerboard is king. The centerboard has it's fore and aft location limits, but it has to be held in place by something, and that something has to be sized and placed in the hull, along will all the supporting structures. The centerboard case fittings need to be made and fitted to the hull. Some can be cut and assembled, but some (most) have to be cut, assembled and fit (edge trimming) to the hull.

I cut out the centerboard trunk parts and use Gorilla Glue ® and some stainless screws (removed later) to attach the two spacers to one of the side panels, and the top cover support rail to that panel and the support rail for it's mate. Then the inside of the "spacer" panel section gets a layer of fiberglass and two coats of epoxy. The glass goes up the sides of the spacers and over the top. The other side panel gets a layer of glass and two coats of epoxy. When cured, the two spacer blocks each get a buttering of EZ-fillet to seal and joint the sides together. Weighted and cured overnight, trimmed the next day.

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While the CB trunk is curing, I work on the layout of the middle bulkhead. I know the forward measurement for the CB and the thickness of the CB trunk spacer. I use this information to determine where I will mark the boat from one of the existing section line cut marks. I then use a giant pair of calipers I made from scrape 6mm plywood, and a cord held by sticks and clamps at the panel seams for measuring. I take these measurements and lay them out on large sheets of cardboard I get from my friends at EdenSaw Woods. I use these cardboard cutout templates to determine fit. If they are correct or need adjustment, I use those new measurements to layout the plywood. I never trace off the cardboard mockups. I layout square lines and measure off the dimensions I just found onto the plywood. Any adjustments are noted and the drawings for that part are made later. The plywood is cut and fit(trimmed to clear the fillets and tape). Reversed and checked for symmetry. Check the bulkhead for level against the still level hull????

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Once I am happy with the location and fit of the centerboard bulkhead, its time to line it all up, mark the hull and cut the CB trunk opening. The centerline is all important now. The fillet and tape are covering the seam and I want to make sure the seam is the true centerline. Stretch a cord tight from the center of the stern to the bow. Line up a straight edge on the marks measured from the station line cut marks. Hang a couple of "bobs" (I use pencil bobs, with strings jammed into holes drilled in the ends of the used up erasers, and nuts screwed on the pointed ends for weight) over the edge and line up the bulkhead and mark it's location. Line up another "bob" with an adjustable square, so the square touches the centerline cord. Mark this location on the top of the bulkhead. Check the bulkhead for vertical alignment. This is a relative term as the hull may or may not be setting on it's waterline(I have an idea where it might be, but nothing to measure it from). What you are looking for is a close square (88°- 92°)between the bulkhead and the CB opening. I use the "bobs" on top and a small square wood block on the bottom to determine vertical, and it is very close from boat to boat. Your eye will rule here.

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Attach, and align with a couple of temporary screws, the partial aft CB bulkhead to the aft end of the CB trunk housing. Measure and mark the center of the forward and aft ends of the now "CB trunk assembly". Clamp the CB trunk assembly to the bulkhead lining up the centerline marks. Drop a "bob" off the centerline cord and position the aft end of the CB trunk assembly to line up. Make any adjustments. Check the position of the main bulkhead again to see if it has moved. If everything looks good, check the bulkhead again for level and square; then mix up some fillet material for some small jump stitches to attach the bulkhead. After the jump stitches have cured, do a full fillet and glass tape on the forward side only.

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As you can see in the photos there is more to the CB trunk assembly than I have mentioned. With the main bulkhead firmly attached, its time to mark and cut the CB opening in the hull. If everything is still square, or make it so; then take a pencil and mark the outline of the CB trunk. Remove the trunk assembly parts and mark 3/8" inside the side lines you just made and 1" inside the ends. You are trying to give yourself some wiggle room here when you make your cut. You will trim the opening when the boat is upside down. Coat all the edges with epoxy and the fore and aft ends of the CB trunk assembly. Clamp or screw, the assembly back into place and check for level and square from the centerline again. Put in a couple of small jump stitches on the partial aft bulkhead and let cure. In the photo I had to put in a pusher stick to make it line up. After it cures, fillet and tape all seams and coat all the trunk area with a couple of layers of straight mixed epoxy. They won't see the sun again. Attach the top and side panels, and be sure to round all edges well for the glass tape to form to and coat. Fiberglass doesn't/won't bend around sharp corners.

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Determining seat height is and ongoing process. I try to settle on 12" above the centerline of the hull for the middle seat. When I was twisting by beard on this hull, I had placed a small full length batten inside and marked a couple of height lines to see what looked good. Once I was happy, I started my measurements off one of the lines. As I got farther into fitting the movable seat, things changed, but not before the stern seat bulkhead was installed. The new plan drawings have the stern seat bulkhead ¼" shorter in height than hull #1. The bow seat and bulkhead was another pulling of hair that I can't afford to lose.

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I use an outside stiffener on the upper edges of my seat bulkheads. They are notched for the seat to rest on and be screwed to. If you want to permanently attach the seats to the hull with epoxy and tape, put the stiffeners on the inside. Cut the rails longer that the width of the bulkheads and trim to fit. Take your time here and get it right. When I install the stern seat, I have the aft bulkhead seat rail already attached and glued to the bulkhead. This gives me a fixed point for installing the rest of the parts. I measure and cut the stern seat for it's designed depth; then cut and trim the width and end bevels to fit(rounded for the fillets). I use the fitted seat to determine where the bulkhead will be located and make some "jump" stitches to hold the bulkhead in place. I install the port and starboard seat side rails after the bulkhead is glassed in. I use some scrap cut to fit, between the stern rail and bulkhead to line up the tops of the side rails. Then glue and screw them in place.

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Before you install any bulkheads or seat panels, its a good time to give them a coat of epoxy. Do them out of the hull and on the floor where they are flat and the chance of runs are at a minimum. This is where the rubber squeegee comes to the rescue again. Do one side of all the parts, cure, flip and do the other sides. Don't forget to get the edges too. The edges are plywood's weakest areas and prone to rot quickly if water gets in.

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The center seat support "wings" height is first set by the centerboard bulkhead and then their alignment with the bow and stern seats. The wings have a small plywood fillet at their stern end, and are double screwed thru the hull to a block attached at the forward end. I stain these ahead of time and hide any gaps with a small fillet against the hull. These will be drilled for "pin holes", later when I locate the seat positions after sea trials. Photos of this will be in a future story.

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I use a rough position line for where the bow seat will go. This changes a little as I align the center seat with the stern seat. You will never have to deal with most of this as the plans will reflect all the heights and placements of the interior parts. The bow seat and bulkhead will be the hardest part to complete, but not insurmountable. The problem has to do with the continuous curves of both side panels at the bow. You will have an idea of that from getting the breasthook to fit. I like to start with a piece of cardboard larger that what the finished seat will be and mark a centerline on it to make sure I trim it square with the centerline. I do a rough trim to get the cardboard to fit close, but not exact. I take a pencil and slip it into the clip on my tape measure and slide the tape measure housing against the side panel and mark a line the thickness of the housing on the cardboard. Now I a have a good line to measure back to my working edge from. I mark a new line "outside" of, and parallel to the "tape housing" line, as close to the edge as I can get, to get rid of any large gaps. This trims the down the cardboard and makes it slide in, closer to the bow. That's why I started with a piece larger(wider/longer) than the final seat. I go to smaller blocks of wood to guide the pencil, or if I was close the first time, I just lay the pencil along the side panel and slide it along as I make a true curve line. I keep trimming to a final fit and then make a gridline system to measure off of for the plans.

I then take those numbers and transfer them to my plywood seat, and with the help of a small batten and a few nails, lay out the curves. The plywood seat is then trimmed, beveled, and sanded to fit the hull. I use a long batten resting on the center and stern seats to hold up the bow seat panel for measuring the bow bulkhead. There is some leeway in the cutting of the bow bulkhead itself as the fillets and tape can fill any gaps. The only thing you want to be sure of is the fit of the bulkhead rail. You want to make sure you have some extra length to trim as you fit the seat, bulkhead, and rail together. Clamp the rail to the seat, trim the rails, and then glue the rail to the bulkhead. This will make things easier for final fit. Just take your time and it will turn out ok. It helps to have some waste stock to play with first. Did I mention that the boat has to still be level and the bulkhead and seat need to match too? The building order is, fit the seat to the hull, level and inline with the other seats. Fit the rail to the seat. Fit the bulkhead to it all. The bow and stern seats also look good if they follow the shearline curves.

Now to attach the gunnel rails. Start with the outside stern rail first, and make it longer than the width of the hull. Level it to the tops of the corner blocks, glue and screw in place. I love my Samona dowel cutting saw for trimming the rail ends flush to the hull. Just lightly press to the hull as you pull.

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The outside rails come next and you want to start at the bow as you will need the length of the stern half to bend the rail to fit the hull of the bow half. I always do a dry fit first and I don't know why I didn't take any photos then. Later when they are covered with glue, you have your hands full keeping them in place and not smearing glue all over the hull. On a Vee bowed boat, you don't have much at the bow to attach a clamp to. I take one of my video lighting "C" stands and support the stern end of the rail as I clamp the bow end as close to the breasthook as possible and with the top of the rail even with it. I then drill a couple of spaced holes in the rail and into the hull and breasthook. I will use these as clamps when I attach the rail. You will have seen in previous photos that I have had the rails pre-bent for several weeks. This gives them a slight curve and helps me install them, and reduces the chance of snapping. Once I'm happy with the fit, I smear on the Gorilla Glue and get ready to rumble(you want it to curve, it wants to stay straight). Drive in the first screw, bend and clamp as you go. Keep an eye on the changing curve along the shearline as you move aft. Once the clamps are temporarily set; go back an line everything up. Sight down the rail to check it, and make any adjustments that are needed for a smooth and flowing curve. Try to have the plywood even with or above the rails as you smooth the curve. Add lots of clamps so there are no gaps anywhere. Come back after you've caught your breath and place stainless screws at the one foot station cuts, from the inside out. Leave a couple of inches of gap for the screws near the stern corner and breasthook. You need the space for the ends of the inner rail screws. The inner rails are fitted pretty much the same way, but when you make the dry run to mark the length, add at least 1/8" past what you think is the true distance. This gives you some wiggle room, and will probably be the true length from past experience. The rails are drilled, countersunk, and screwed from the inside at the half marks between the station line cuts. The oarlock supports go at the station line cuts referenced in the plans. Cut out the radiuses in the corner blocks and then trim, round, and sand all the corners and rail parts. I do not like to use a router rounding the rails. I have had bad experiences with blow outs, with the rails under such high tension from the bending. Its more fun to use the rasp and a lot cleaner. The plans go into greater detail of how to shape the transitions between the rails and the corners.

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A couple of shots of the hull with all the interior parts installed. The centerboard shot shows the middle seat in it's forward position. The making of the centerboard and rubber will come in a future story. Part Four will have Laura getting her bottom seam taped, faired, glassed, weave filled and painted (if the paint is ready).

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Until the next time.

Warren Messer

Stitch and Glue and Stylish Too!