Under the Surface

Before the hull planks go down and create the beautiful curve shapes, the interior frame work has to be ready for the hard work. The boat must be built strong enough to be lifted by three points, one in front and two from each side of the stern. It would be a grand shame to see the boat chained and raised off the temporary trailer, and watch it drop from a failing U-bolt. 

The same area in the back will also needs strength to hold a ski/tube rope, and tie downs to the trailer when traveling.

The top of the back cross frame has been cut off to make room for the motor well, but the remaining C-shape sides are the most obvious place to begin building strength.  

More plywood layers were added on the inside and out, connecting the top and bottom to make a strong outer panel. They are bonded with epoxy which is very tough and does a better job of filling gaps than most other glues. 

If I had planned perfectly, the outer longitudinal beam would have been right up against the glued layers. But instead, the deck needed more space for the folding ladder, so I had to add some filler layers.

To fill the gap, I epoxied the marine plywood blocks to the long beam. The speckled markings are shallow holes drilled to allow the epoxy to grip a deeper layer, and resist a shear sliding force.

Next, another plywood panel was constructed beside the longitudinal beams. It is beginning to show the 3D shape of the stern extensions.

This is the group of eight plywood pieces that went into making the left (port) side wall. The right side was about the same. It did get a little complicated. The morning that I planned to glue both sides turned into a whole afternoon and made me late for supper.

Since the middle wall was slanted out, in the way that looked best to me, I had to make some perfectly angled wedges to glue in the gap.

They were made from a Douglas Fir 2 x 6. By angling the cross cut fence and flipping the board over each time, eventually I found an angle that worked great. 

Since the wedges were cross grain, when I applied the epoxy, it soaked in to the large pores and (I believe) became a very strong wood and epoxy link. 

If this was a production boat, I suppose some testing would be in order to see if my seat-of-the-pants engineering worked out. Especially since the last time I took the 2016 wood boat to the dealer for motor service, they told me that the transom was cracking.

Now this was a surprise, because it has always been a concern. I do inspect on occasion to see if that last big wave or the bumpy railroad tracks, may have crossed the limit of the transom’s strength. So, I asked the mechanic to show me the problem area, and he pointed out some cracks on the back stern panels , not really a part of the motor mount area. 

It is annoying but fortunately not serious, as the issue is sun damage. The mahogany veneer is developing small cracks because it was less protected under the boat lift canopy. So, with no major engineering failure on the previous boat, I take it as my cue to carry on. Inspectors Jeff Margush, Don Florea, and Andrew Alger will be relied upon to set me straight.

The stub cross frame now has five half inch marine plywood layers, and the longitudinal panel has three layers.

Slowly, slowly, the work on the inside frame is getting done. It gets tedious, and without glamour, to put some pieces in place that soon will never be seen again. But when the big waves and bumpy road comes to stress the pretty boat shell, what’s inside gets much more important and obvious. It is like a life well built. 

Inner Trim Line

The outside deck line is created with the 1″ x 1.5″ long molding called the sheer line. The next step is creating the inner trim line which defines the deck and the seating space. The blue tape seen below left is first visual experiment.

For the molding, I picked a 12 ft. piece of straight grain cherry. Granted, it is not the world’s first pick for boat building wood, but it is available, of medium density, and works superbly. I also had plenty on my wood rack so I decided to “shop local.”

To make a 22 ft. continuous molding, I had to splice two pieces with a 20 inch long scarf joint. It goes the full distance of the paper below. By making it long, it allows basically the same bending characteristics as the other solid pieces.

The left side is shown with the long molding ready to install. The nails and string show the refinement of the line, and allows a visual inspection to see if it follows a regular or “fair” curve.

It passed muster and served to position the cutout notches. They were cut with a hand saw, chisel and rasp, as needed to seat the molding the right height and along the curve.

The most difficult notch was the front, which did not go all the way through. I cut as far as possible with the Japanese pull stroke handsaw (bought at Menards).

Necessity is the mother of invention, so I figured the drill might do as well as hammering with a chisel on the white oak front frame.

Then a bit of the easier vertical chopping to take out waste.

And the half mortise was ready to final fit.

After the curve of the entire runner was micro adjusted to suit the eye, it was bent into the notches and bonded with epoxy. It becomes a visual line and a strength element, and the structural organizer for all of the interior spaces.

The umteenth step of the impossible journey is done but a seemingly endless list awaits. Tomorrow . . .

Curves and Corners

From the beginning of building a boat, a grand attempt is made to follow plans, if you have some which I do not, and keep both sides symmetrical. That applies especially to the level, straight and and flat parts.

But the most visible and beautiful lines on a boat are at the edges, on the side, and the transom end. Those are mostly curves that are not so easy to measure, so the eye makes the final judgement on whether a line looks fair and pleasing.

This time it was figuring out the outer, lower curve of the transom. As usual, it starts with a pencil on paper. Then, I often use a thin bendable stick, shown at the bottom, to visualize the full size 3D shape.. Below, the bottom pieces complete the line, and compliment the top deck edge molding (sheer line), in smooth symmetrical curves.

Here is the side view of the full size cardboard and 1/4″ plywood patterns in preparation for the curved back corner lines.

Admittedly, the wooden boat building world is small, but when I hear of another builder, I like to meet and discuss construction ideas with them. So, it was my pleasure recently to be introduced to Charles Onyon, who has an interesting resume’ including working four years at Van Dam Custom Boats. A few years ago, I visited and took a tour of their inspiring shop, likely the premier boat building company in the country.

Charles came over to visit, and gave a far more educated scrutiny of the boat than the average house guest. He knows boat building including wood types, joinery, paint selection, and engineering for strength and esthetics. He is smiling because most people don’t know he is a celebrity . . .

3D Boat Shape

The end of the story from the last post is shown below, as I am tuning up the final angle where the sheer log meets the bow. It may look simple enough, but hanging on to a screaming body grinder at a precise angle with 36 grit paper is no casual task. I could have used a saw and a file, but, if the edge is visible and there is room to move, it is the fastest and most direct path toward completion.

I have long wondered what built by hand means, but if it is anything beyond shaping something strictly with your fingers, then this concentrated, practiced effort has to qualify also. Taming the body grinder is on par with training our Boxer dog Buck.

He never was fond of the leash, and pulled continually toward the next interesting scent or dead treasure. We always had to be prepared for the surprising and potentially injurious jerk, should any rabbit or any other animal jump to flee.

The grinder can be a lot like that dog. It pulls, it whines, it catches and jerks, all the time requiring it be handled with gentle pressure. But if it is mastered, it pulls as hard and fast as an Iditarod sled dog.

Those long sheer logs or moldings are now faired, and assembled into the framework of the boat. Now, it allows the imagination to go down the road a ways, as the 3D shape is coming into view.

Sheer Magic

The line where the top of the boat meets the side is called the sheer line by traditional builders. It is never straight, and is a defining shape of the personality of the boat. Sometimes it starts high in front, to cut the big waves, and comes down in the middle perhaps for rowing or fishing. This beautiful rowboat shows that reverse sheer.

My speedboat on the other hand, will not be battling such severe weather, but will need great visibility forward at all times. In this case, it has a positive sheer line, lower at the front to see across, and higher in the cockpit area for seating comfort and wind protection.

The line always curves inward toward the front, and the whole shape must be “fair,” a beautiful shape. Fairing a curve means making the shape flow with out hills or valleys. Lumpy does not make a winner. The best help for a good curve is a slender board long enough to go the full distance, thin enough to make a consistent bend, and thick enough to resist distortion between supports.

I chose a piece of cherry, and sized it to 7/8″ x 1-1/2″, and then had to splice together 2 twelve foot pieces to make 20 ft. As noted in the last post, the first one broke under the pressure of bending. I picked a straighter grained piece, thinned it a little, and started over. Below is the scarf joint, angled over 14″ so when glued, it will behave mostly like a solid original piece.

Then, the process begins by cutting a notch at the corner of one cross frame, and gradually fitting the sheer log in place. The photo below shows starting in the middle, using a bungee cord to hold it and then going on the next frame. Not a step to rush, as it will be examined, praised and criticized ad infinitum should this boat ever get on the water.

My friend Stan Oyer asked if there is a point in boat building when you have to give up the tight tolerances of levels, angle guides, and tape measures. Yep, and this is another of those many times. Below, I spring clamped two straight sticks to the extended sheer molding, just to see if the angle is similar side to side. I did not measure, or level up, but just got back and looked at the two sides from a couple of angles. My conclusion is that they are beautifully compatible, if not perfect.

On to the seat framework coming up . . . You are never lost until you are out of time.

Boat Turning Party

The boat strong back has finished its purpose, and was dismantled (last post), but as soon as the hull is turned over, it will need to be held up by another support, generally called a cradle. Since it is also temporary, it was built for braun and not beauty. It will have to hold up, reasonably steady, the increasing weight of the boat and occasionally my weight as I climb in and out.

The legs are 2 x 4s recycled from the legs that were holding the cross frames. The other pieces are are random 2 x 2s or 2 x 4s that were laying around the shop. It is not easy to see, but the two boards that contact the hull have a cardboard cushion to avoid scratching during the next phase.

Last, the angular center piece is to give front to back rigidity, and prevent falling easily. If this isn’t enough, I may need to add some diagonal bracing later on.

As before, we needed the 2 x 4s attached to the ceiling joists, and Jeff Margush was agile enough to climb and get the job done. It is amazing what a few screws and a T-shaped 2 x 4 can hold, but from the look of the head scratching, I have some questions! I gained confidence considering that the thick yellow rope worked on the past boat.

Then the moment came to tie it up, lift and begin the turn. The rope prevented danger or over laod on one person.

We should have removed the legs from the first phase, as they got in the way of the ceiling and almost broke the light. But damage was averted with patience and moving it forward.

As the hull came down right side up, we settled it down on the custom cradles. It is remarkable how much construction on a boat is for strong backs, legs and bracing that eventually gets removed, leaving the boat alone.

Thanks to Jeff Margush, Johnny Crist (front) Marvin Metzler, Carsen, Aiden, and Jeremiah Greve, Leonard Nafziger, LT Newland, Stan Oyer, Jeff Bonta, son Jason Bonta and son-in-law Doug.

“It is not the end, only the end of the beginning,” said someone famous. And now the joy of seeing the boat up right. Much more work to do so we carry on . . .

Good Bye to the Strongback

Sooner or later, the endless list of final things to do comes to an end, or at least to the beginning of a new stage. A lot water has gone over the dam since the beginning of this boat started about 7 months ago. The strong back is the under assembly of horizontal 2 x 6’s and vertical legs that was built to hold the cross frames in the right position.

Gradually, longitudinal beams were added to connect and strengthen the frames.

The keel was added and the transom was mounted inside the support beams.

The hull planks and the chine runner were installed.

The second hull layer was added and faired.

Keel rounded . . . check, chine flat filled with epoxy, front end given overlay bullnose, stern overhangs cut flush, the transom cutout stiffened . . . check, check, check.

Then the day came to dismantle the strong back. The long screws were taken out to release the 2 x 6’s, and most of the legs of the cross frames removed.

It is now ready get turned over and rest on the cradle, for stage two. . .

Creating the Bow Profile

After the cross frames take shape, the profile of the bow line is the next most important visual. These days a wide variety of design style abounds. The front of Redemption, my first boat, followed the upswept, pointed lines of the long sleek ocean racers.

A more contemporary front design shows a reverse, back-leaning bow line. For a slow moving boat like a cruiser or a sail boat, the result is a longer the water line compared to the width, for better performance. The downside is that especially on faster boats, waves will tend to come up the side easier, making for a wet ride. It is still a visual and functional mystery to me that anyone would use it on a speed boat.

Below is a straight upright bow line, which imitates the tradition of the old runabouts, and looks good sitting still. However, as soon as these boats get moving, they take a plane angle with the bow up, and the front angle tips back awkwardly.

The sketch below by Jeff Margush shows respect for the traditional, neat vertical front angle, but in my opinion will look good sitting or at any position from take off to high speed plane. Of a couple dozen photos and drawings of mine and Jeff’s, this one sits currently at the top of the pile for inspiration. The rake of the windshield may not be imitated . . . this time.

The first experiment extending the front was a cardboard pattern to test the visual sense, which is doubly hard being upside down.

Adding the angled piece below was judged to be too upright.

This is the angle settled upon, and is now rather firmly established, being set in the “concrete” of boat building, epoxy.

Although the side planks will not be permanently fixed until a later stage, I added three on each side just to see if we are headed in the right direction. With some sculptural attention to the chine line, it will eventually “fly.”

7-6. The Fine Art of Fairing

All of the cross frames, and longitudinal moldings and support parts just serve to build support for the shell of the boat, in this case the hull. The intention for the back 6-8 feet is that the surface should be flat for most efficient planing. At first glance the surface below looks flat, and it is pretty close, based on preparation faring work on the frames and stringers.

The tools of the trade for this task are the straight edge, a plane or two, these from Lie-Nielson, and the home made long sanding board.

Pencil marks show where the hull was slightly high, and the block plane or the low angle jack plane start to flatten the area.

Then some sanding with the long board, to only hit the high spots, eventually tames the mildly lumpy surface to a happy, fair curve.

When you are hitting a ball, you have to keep your eye on it, and you might be able to play music by ear. But the if you are testing how well the hills and valleys of a surface are “faired,” the final judge is the hand. You could do it with you eyes closed.

The Art of Persuasion

Jan’s Grandma used to say “A man convinced against his will, is of the same opinion still.” I guess that could apply to a dog also, like Buck who would sit at the end of his chain beside the electric fence, as his head bobbed every current pulse. Sometimes, even a board has an “opinion,” with internal forces that show themselves when it is cut, springing apart or pinching together.

So when building furniture, parts are cut slightly over size, to discover any internal stress causing bend or twist. Then the edges can be straightened and the twist removed, before assembling it into the piece of furniture.

Boats, however, have so many curves that require different techniques to build and assemble. Laminating a straight piece to the curved chine stringer requires a bunch of clamps to persuade it to lay smoothly against the others.

Another example is in the machining of the tongue and groove planks. It is dangerous to have hands pushing small, thin parts near the cutter head. These angled feather boards are clamped with pressure downward, and inward against the feed stock, to allow hands farther away from the danger zone.

In the case below, the two ends of planks did not want to lay flat and made it difficult to fit the next piece. As the screw block is tightened up, it forces the edges together and the next grooved board will fit and hold them flat.

As the hull planks are assembled, some clamp pressure is needed to conform to the curves of the frame work.

Below, the angle block is shown which was temporarily screwed to the frame to hold the clamp securely. When the final assembly with epoxy was done, the clamp was replaced by screws to hold the planks in place.

Assembling the second side needed another temporary block to hold the clamp, and screws hold it together as the epoxy cures.

Where the planks come down meet the chine rail, the fit is more difficult. For a long curve, the cut can be done on the table saw to make an over sized plank.. It is a bit dangerous, but slow, steady cutting with gentle side pressure produces a good starter piece.

Below, the bottom plank was angled out too much, so the saw was used to cut through the contact point, so the wood block could push the bottom part inward. The clamp and screw with a large washer are used to hold it solid when the epoxy is added.

Temporary hammer blocks help to press another bottom piece in place, testing the fit. As it meets resistance, I mark the contact spot and continue sanding or cutting the high spots away.

At the end of many trial attempts, eventually the plank can be hammered by the “Persuader” fully into place with the plank fitting well to the rail. The pieces marked with green tape show which ones still need to be removed and epoxied.

Finally, only a few planks remain to be fitted on the second side. It breathes a sigh of relief, nearing the end of a great step of progress.

Next up, some fairing, a second layer of thinner plywood, and paint before turning the boat over for phase two!