Plywood Sides

The boat has been progressing well over the end of year period!

I continued work on fairing the starboard side of the boat to get it ready for the installation of the plywood side panel. Following the recommendations in the book 'Boatbuilding with Plywood', I faired the frames to ensure they would not protrude against the plywood panels. 

Because the bend required around the transom is quite significant, I decided to pre-bend the starboard side panel with a jig. The plywood was steamed with boiling water and towels. I am unsure if this was worth the effort because the port panel bent into place with equal effort without this pre-bending treatment.

Steaming starboard side paneling to conform to transom curvature

 The plywood was clamped into rough position and the bend at the stem was created with the help of towels and lots of boiling water. After the plywood dried, it retained some of the bend allowing it to much more easily conform to the required shape. I would highly recommend steaming the plywood into place with this method as it makes the job much easier.

Steaming starboard planking at bow

The bend in the starboard paneling at the transom caused some trouble because the outer layer of plywood (in tension) developed a crack of about 2.5cm. This caused a noticeable kink in the side panel. To solve this problem, I laid the plywood on a flat surface and glued up the crack with epoxy. Gluing up the crack worked remarkably well with the plywood bending appropriately without cracking. To me this is a testament to the excellent properties of epoxy for boat building applications.

Starboard paneling crack glued up and preforming perfectly after sides are glued on

 In order to dry fit the plywood paneling, the positions of the screw holes in the plywood panels needed to be determined. This was achieved by clamping the panels in place and tracing around the shears and chines to mark their positions on the plywood. The plywood was then laid on the table and the hole positions were marked along the sheer and chine lines at a distance of 3 inches apart. The screw holes were drilled and countersunk on the drill press, which facilitated the countersinking of all the holes to the same depth.

The panels were initially fastened to the side of the boat with 6 gauge wood screws as a dry fit. The screw holes left acted as pilot holes for the final silicon bronze screws which are 8 gauge.

Dry fitted port panel

 Fortunately, I had the help of my friend Steve for the gluing on of the side panels. It was a big job which took 3-4 hours. Firstly, I sanded all the mating surfaces and gave them an initial coat of epoxy allowing 45 minutes for the epoxy to seep into the wood.

All mating surfaces coated with epoxy

Thickened epoxy was applied to all the mating surfaces before the panel was screwed in place. Although it would have been possible to do this myself, I would definitely recommend having some help for this stage. Two drills are very helpful for installing the 100 screws in each panel.

Note that I had already trimmed the plywood at the stem when it was dry fitted.

Installation of  port panel.

The starboard panel was fitted in like manner to the port panel. A clamp was used to hold the plywood against the stem. Using pop-sticks, I applied thickened epoxy fillets to all the internal plywood-frame junctions.

Side paneling installed

 Additional clamps were required to hold the plywood in position near to the transom

Clamping plywood at transom

After the epoxy had cured, the plywood was trimmed and sanded at the front of the boat to form a curved line that hopefully will one day cut through the water like a knife through Camembert.

Trimming plywood at bow

Installing the side plywood felt like a important milestone. 

My boat has gone from looking like a  just a wooden frame to actually looking half like a boat!

I have started the fairing of the bottom of the boat and have scarf jointed the plywood panels for the bottom. As a whole, I am happy with how the boat is progressing and I am hopeful that I can get the bottom paneling on before the summer is over.

Scarfing and more Faring

It's been a massive 6 months since my last post!

The boat has been progressing very slowly for several reasons.

Firstly, fairing takes quite a while and I am being a bit of a perfectionist.

Secondly, it has been winter and not ideal for using epoxy.

Thirdly, I have been quite busy with things which are more important than boat building.

I haven't put down the tools thou! I've had fun making play props for a youth group play along with some cool signs for the SYP Hebron Study Weekend which was themed 'Leaving Egypt Behind'.

'Egypt' and 'Promised land' signs

Before scarfing, I determined the approximate size of the sheets and cut them to the approximate size required.

First attempt at placing side panelling

Since my last post, I have scarfed the side panels and have worked on getting the fairing correct.

Half way through cutting the first scarf joint

The scarfing jig worked perfectly on the first attempt and not as well on my second scarf joint, as can be seen by contrasting the photo below with the photo above. The plywood was a little bowed on the second attempt and a flaw in my jig is that it doesn't hold the plywood down to the table once the scarf is cut. I am confident that the jagged edge will not affect the quality of the scarf joint however.

Second scarf - quite jagged edges

Because it was getting cold when I did my first scarf joint, I covered the joint with boxes and put some incandescent globes inside. This managed to raise the temperature to 20 degreesC which is a suitable curing temperature. I thought it best to ensure a good curing temperature for such an important joint in the boat.

Initial soak-in coat of epoxy in improvised 'hot box'

I was very happy with my first scarf joint. It worked perfectly and even the grain in the wood sort of lined up!

 I would recommend attempting scarf joints. Making the jig and cutting the scarfs is the hardest part.

Completed scarf joint

Mounting a flat table top over my boat helped to facilitate the scarf jointing. A4 plastic sleeves were used to stop the joint gluing to the table.

Second scarf joint curing

One of the problems I encountered when fairing was insufficient material on the forward part of the chine. For this reason, I glued in another piece of wood to allow a convex curved hull.

Adding extra material to chine

As it happened, the first piece of wood was still not sufficient; therefore I glued another larger piece of wood on both sides after a significant amount of planing. 

I think that perhaps this could be in the running for the most clamp density used on a boat build!

There was quite a twist required in the wood.

Adding still more material to the chine

The port side of the boat is fully faired now. Using rags and boiling water, the plywood was eased into the bends required at both the stem and transom. The bend on the transom is the most significant and I have a small amount of concern that there is a risk of cracking the plywood.

Plywood fitted and nearly ready for gluing

My plan is to glue the sides on the boat over the end of year period. Hopefully I can also glue the bottom on before winter next year. 

I am still really enjoying my boat build but the problem for now is that I don't have any annual leave left for this summer.

Slow and steady persistence will have to be my boat building maxim for now!