Planking Complete

The planking is now complete. It was basically a straightforward process - cut the scarfs on the ends of the planks, cut the rebates on the bow and stern sections and then glue them in place after beveling the edge of the previous plank. Even though it was straightforward I managed to make a couple of mistakes with the scarf joints. The first mistake was that I didn't apply the clamps carefully enough on one scarf and ended up with a wide strip of exposed white epoxy. This won't look good on a clear finished boat and I am not keen on the idea of inlaying a clean piece of veneer to hide the joint - if it isn't perfectly done it will be as obvious as the white epoxy!

On the middle plank on the other side of the boat I managed to cut the two scarfs on the same side of the centre section. I had already cut the scarfs on the fore and aft sections so I had to cut the incorrect scarf off and make a new one. Cutting the scarf off lost 50mm of the plan's length; the new scarf effectively lost another 50mm. The planks in the kit are cut with some extra lengths to allow a damaged scarf to be recut but doing this would only lose part of the scarfs 50mm length. The result of this is shown here.

The only way to recover from this blunder was to and an extension to the end of the bow section. This resulted in two scarf joints being close together. This is another  nail in the coffin of the varnished boat idea and I will now paint the outside of the boat.

In this next phot the C clamps are clearly visible as are some home made screw clamps where the C clamps can't be used because there isn't enough clearance between the hull and the mold.There are also a couple of good old metal screw clamps in there and a couple of V clamps holding the planks to the stem. These V clamps simply hold by friction but only work on a shallow angle.

Here's the fully planked hull.

at this point I removed all the temporary screws holding the keel, inner stem and transom to the mold and tried to lift the hull off the mold. It wasn't easy because the squeezed out epoxy inside the hull was sticking to the sticky tape and plastic which was in turn stuck to the mold. Fortunately the protective layer of tape and plastic had done its job and I was able to lift the hull up.

While waiting for the planking glue to go off I have assembled the "buoyancy tank". This is a trapezoidal shaped box which sits on the keel in the middle of the boat with the sliding seat mounted on top of it and the outrigger arms attached to the aft end of the box. The top, bottom and ends have corner strips glued to them and finally the sides are glued on. In this photo the sides are being glued in place - a tricky clamping exercise to hold the ends of the side panels down. The tape was sufficient to pull the joints together along the long edges.

After cleaning up the box I couldn't resist a test assembly of the box, the outrigger arms and the sliding seat. Now this weird shaped box begins to make more sense. there is auite a bit more work to be done on this assembly and I will do that while waiting for the epxoy to set on the outer keel, cutwater and skeg.

Transom and Garboard Planks

The transom needed a piece of solid timber about 450 mm long by 300 mm wide. I had some nice PNG Rosewood that was 110 mm wide so I ripped 3 pieces 20 mm thick and edge jointed them  before putting the single piece through the thicknesser leaving it slightly over the 16 mm. I wanted to put the boat's name on both sides of the transom using inlayed letters of a different wood. I have a small CNC mill and used this to cut the recesses for the letters in the transom and then the letters themselves. The letters were glued in place with epoxy and then sanded flat.

Now you are probably wondering about the name and why. Remember, Google is your friend! You can't see it but the same inlay is on the other side of the board.

Before the transom could be glued to the end of the keel the keel was lifted off and the edges cleaned up, ie excess epoxy removed. The protective tape, so the hull doesn't stick to the mold was replaced, and the keel put back on the mold. The transom was glued to the end of the keel and screwed to the mold through the corners which will eventually be removed.

Next step was to bevel the edges of the transom so that the planks will lie nicely on it and get a good glue joint. This bevel is tricky, the angle changes continuously. I started out with the power plane with the wooden arm. By riding the arm on the stringers and the next frame the plane cut the correct angle but was awkward to use on a convex curved surface. Then I noticed that my belt sander had a tapped hole in the side so I made a wooden arm to fit it. This worked like a charm and I made a perfect bevel quite quickly.

Here are the two tools with their outrigger arms.

Clamping the planks to each other along the stringers it tricky because a lot of clamps with a long reach are needed. Allan Will suggested C clamps and wedges. I have used this approach before but needed to make a new set. Here they are, various thicknesses of scrap plywood (10, 12, 14, 16 mm thick) cut on the bandsaw. THere are 50+ of them in the stack. They are used with wedges which I have a heao from previous boats.

Preparing the garboard planks (3 each side) involved cutting 50 mm long scarfs on the ends, a rebate or gain at the bow and stern and, because the transom is curved where the planks land cuts had to be made along the inside of the planks so it would bend to the curve.

Here a rebate is being cut in the standard way using a rebate plane.

The cuts so the plank would bend were made with a Dremel with a 1 mm router bit. The Dremel was slide down a ramp so the cut went from the surface to about 4 mm deep in the 6 mm thick plank. Having made one cut the ramp was moved to the next position and another cut made.

Here is a plank with the cuts, they are about 12 mm apart and 200 mm long.

Here is a view from the stern  with 4 out of the 6 planks fitted. The planks are held down by screws along the keel where the holes will be covered by the outer keel.

This is a view from the bow with the forward garboard sections being trial fitted. More of the Vee shaped blacks were needed to pull the planks together around the stem but using them avoided screw holes which would have been visible in the finished boat.

Last photo shows the stern section of the  middle plank being glued in place.  Pulling this planks down onto the curved transom was difficult and needed some messy work with a long clamp and a spanish windlass.

More planking tomorrow but then I am going sailing for a week with some of the WBAQ members at Lake Cootharaba.

The Kit Arrives. Inner Stem, Keel and Outriggers

The kit arrived at the transport company's depot and I collected it. Here it is.

Inside the pack were four and a half sheets of 6mm ply. Each sheet had been CNC cut with the pieces held in the sheet with short tabs. Here are the four full sheets - you can enlarge the photos by double clicking on them.

First job was to laminate the 3 layers of 6mm ply that form the inner stem. Where the pieces join there is aan individual puzzle joint so the pieces can only be assembled in the correct order. Here they are wrapped around the mold with plastic to stop them sticking to the mold and plenty of clamps.

While the epoxy was setting on the stem I laminated the five pieces that make up one of the outrigger arms. There are 3 pieces of 6mm ply with outer layers of 4mm solid timber. The laminations are kept in place by the bolt at the left hand end of the jig. With this pulled tight the clamps are applied progressively to the right.

Here is the complete lamination held in  a pipe clamp to stop (or reduce) springback until the epoxy is hard.

The rest of the keel is made up of 2 layers of 6mm ply put together in sections and glued with epoxy. No photo of that but essentially the same as the stem. Once the stem and keel are glued (and screwed to the mold) the edges have to be bevelled so the first plank can be glued to them. I did this with a Ryobi cordless planer fitted with an arm the outside of which is in line with the base of the plane.By running the arm along the lower stringer (where the plank will sit the plane is held at the correct angle for the bevel.

Here are the pair of outrigger arms after some initial cleanup. When in the boat the oarlocks will be in the hole at the rounded end, the far ends are joined together at the keel and the mid point is bolted to the gunwale.

Next step is to make the transom, fit it to the mold and glue it to the end of the inner keel. While that glue is setting the aft end of the garboard planks has to be prepared.