Ways to Give

Inside IYRS Blog

Learn what it’s like to spend a day in the life of a student.

Nov 2

Written by: Tom
11/2/2011 7:49 PM 


This is particularly true when you're using the molds to support an existing boat.



Come to think of it, I can't think of any reason to use the female molds unless you're supporting an existing boat. I've never seen that method used for building a new boat. Of course, saying that all but guarantees that someone will write in with photos of a new build using female molds. Excellent. I'd like to see it.

The boat is now almost entirely obscured by molds, at least when looking at her from the ends.





Inside the boat, there's not a lot left.



Many of the floors have been removed, as well as the sheer clamp (a long member that runs along the inside top of the hull) and the bilge stringers (similar to the sheer clamp, but set down lower in the boat). You can see the bilge stringer here from before (red arrow)



and the sheer clamp is hidden underneath the deck and behind the coaming (blue arrow).

The Watch Hill 15 crew are moving right along with their molds. They should all be up soon.



Some are being final shaped,



and some are waiting to be set up.



The transom form is now set up and braced.



This one is extra sturdy because the wood for the transom will be bent right on this form.

You've seen the way that the shape of the forms has been copied from the lofting, but there are some parts where this method does not work. The stem parts, for instance, have sharp corners that can't be routed out. For these parts, another method is used to transfer the lofting lines to patterns.

One way to do this is with nails.



The edges of the heads of these nails are sharp, and the nails can be set along the lofting lines with their heads driven into the line.



This leaves the upper sharp edge of the nail exposed. If you were to place a piece of plywood on top of these nails and press down hard, say, by stepping on it, the upper edges of the nail heads would cut into the plywood and leave you with a perfect dotted line that matches the lofting line. Connect the dots, cut to your line, and you have a pattern that perfectly matches your lofted shape.



You can check your fit by placing the finished pattern back onto your lofting to make sure that it perfectly matches the lines. This is also a good way to check that your pattern joints are accurately matched as well. If you look carefully at this stem pattern, you'll see that it is made up of 2 parts that notch into each other.



When your patterns fit together just right, all you have to do is cut your parts exactly to your pattern, and your parts will fit as well.

Over on the dinghy project, the stem has been assembled now, and the rabbet is being cut.



You can see the small, square plugs on the outside curve of the stem. These seal in the bolt heads for the through-bolts that hold the stem pieces together.

The planking on the dinghy is quite delicate, only 1/4" thick. This means that the rabbet is also delicate.



This student is holding a fid (a stick representing the plank thickness) in the rabbet to check the depth and angle of the slot.

The keel is finished, and will be installed soon.



The transom knee has been cut and installed for this boat as well.



The wood used for the knee is called Live Oak. It's a very slow-growing, dense wood with interlocked grain. This means that the grain doesn't grow straight and parallel, like, say, cedar. Instead, the grain weaves in and through itself. If you tried to split a live oak log, you'd be at it all day... it just doesn't split like a chunk of regular firewood might. It tears apart like stringy taffy. This makes for a very strong part that holds fasteners well. It's perfect for a structural part like this knee.

Live oak is not just used for little boats. This massive log will be cut to make a knee for the whaling vessel Charles W. Morgan.



The wavy, interlocked grain can be quite beautiful



And in case you'd like to drop down to your lumber yard for a little live oak, best to call first. Live oak is a protected species, so it can't be logged except in cases where the tree has already fallen or was dying. That huge trunk section above came from an area that had been inundated with salt water during hurricane Katrina. The salt water was in the process of killing the tree and the town cut it down before it fell on residents.

The first years continue to put their backbones together.



These students have finished their stem rabbet and are bolting the stem to the keel.



At the other end of the keel, the stern post and skeg have been attached.



Notice the 2 wooden circles along the side of the skeg and at the back of the stern post.



The plug on the back of the post hides the head of a bolt that goes through the post and into the skeg. The plug on the skeg hides the nut for that bolt. In order to bolt these two parts together, the students had to drill a very straight hole from the stern post into the skeg. Then, they trusted that they had drilled accurately, and drilled that skeg hole to intercept that first hole. This allowed them to poke the threaded end of the bolt through the stern post and skeg and have it emerge through the side of the second hole, where a nut and washer could be placed on it and tightened down. After that, both holes were plugged (we call it Bunged) to seal them up.

The bungs are then planed flush with the surrounding wood



and after the whole assembly is painted, you'd never know that they were there.

As you can imagine, drilling both of these holes can be a bit nerve wracking. Here are 2 students carefully drilling the first hole. The student on the right lines up the drill from side to side while the student on the left makes sure that the dill is level.





The centerboard trunks are being finished up as well. The fitting starts with setting up the oak end posts in the slot in the center of the keel.



The sides are then fit to the keel and posts, and then fastened.



This student is using a bit brace to drive the screws home. The brace is one of those tools that's still often used by boat builders. It gives one great control over driving screws along with a tremendous amount of torque. We still use electric drills for making the holes, and a drill can be fine for driving screws, but a brace can give you more precise control over how fast your drive your screw, and how much stress you impart. It's not hard to twist a bronze screw apart when driving into oak.

After the trunk sides are fastened into the posts, the whole assembly is given a coat of primer paint.



Next week we'll see the way that the trunk is sealed tight against the keel to keep it from leaking.

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