Centreboard and case

The centreboard is made from two peices of 9mm ply sandwiched together and it pivots on a 10mm stainless steel bolt. Here are some photos of the construction of the centreboard case and central frame.

Two halves of the centreboard case with the 25x50 mm frames. The sheets were sandwiched onto 25x50 ends as well.

A 9mm reinforcement section was added where the pivot bolt hole would be drilled.

Inside was coated with 5 coats of neat epoxy.

.....not forgetting the inside of the pivot bolt hole.

Two Halves were then joined together

squeezing out the glue, but not all of it.

Meanwhile the two sheets of 9mm ply for the centreboard were prepared.

Added on a section at the end of the centreboard to bring it up to the correct length.

Tried it out to make sure it all worked.

Then lined up the case on the hull to cut out the hole.

Pre-drilled some holes for 4x25 screws to hold it to the hull.

Put a bed of thickened epoxy around the hole.

I scored the bottom of the case frame and coated with neat epoxy.

Epoxy fillet was rounded off at the bottom of the case. Excess glue scraped away.

Before it cured, I rigged up something to keep it straight and upright.

25x50mm frames were inserted between the hull and case for the thwart and the central frame was put in. I may have made the hole in the frame too big but sure I'm not getting paid to do this!

Rubbing Strips

The rubbing strips were done lat year. I decided to put them on to give the boat a more classic appearance. they are not part of the plans but similar boat have them and they look good. Also I had the wood left over from the outwales. They are the same 15x25 strips used for the outwales. I put them at the bottom of the top plank in the hull. They were glued into place and screwed from inside the hull with 4 x 20 screws every 20cm. Putting them on was one of the hardest jobs on the boat up to that point. my daughter held the rubbing strip while I screwed it to the bow and worked my way aft, all the time it was dripping glue. I had to press it hard against the hull and reach over with my other hand and screw in the stainless steel slotted countersunk screws. I used a lot of bad language that evening. Daughter heard all of it.

To keep the tension on the strip at the aft end of the boat I tied the strip to the opther side of the boat and left it there for a day or two. After the epoxy cured I redid the screws and countersunk them properly. I removed the excess from the aft section.

To make sure that the starboard strip was in the same place as the port strip I cut sections of wood and placed them between the outwale and rubbing strip and various distances. I recorded these distances and marked the corresponding positions on the other side of the hull. I then taped the peices of wood to the hull as shown below.

I trial fitted the starboard rubbing strip to the hull and marked its position with a pencil. The photo above shows the gunwales with the hull sitting above them. This is because I didn't cut that plank along the line deliberately so that I could plane down to the gunwales when they were fitted - much easier to get a good finish if you do it like this - or at least it is for me. The starboard strip was tied to the port side of the boat to maintain the tension on the wood. Most of the tension is at the bow but you can screw it into the inner stem which gives it a good hold to start.

The photo below shows the starboard rubbing strip in position. Bot rubbing strips and gunwales were positioned with a couple of centimeters jutting out beyond the front of the hull. This was to allow them to mate up with the outer stem which has yet to be fitted. (At this point of writing it has actually been fitted. This work was done last year).

The excess wood from the rubbing strip and gunwales was removed carefully so that the outer stem could slot into the space.

Below the finished result. Total time was about six hours. Should see more photos of it later.

Outwales

The outwales were put onto the boat in a similar manner. The wood was primed and then coated in thickened epoxy after a couple of hours. Starting at the bow the gunwale was clamped to the boat and screwed into position using 4x35 stainless steel screws every 20cm.

Clamps were left in position for 36 hours approx and removed so that the epoxy could be cleaned up. All preparations, glueing and scraping took about 8 hours, same as for the inwales. The hull was then shaved down to the level of the gunwale and the sharp corners of the gunwales rounded off slightly.

Inwales

This work was originally done last August. The inwales are 15x35 Douglas Fir. First the hull and inwale were soaked in neat epoxy for a few hours and they were then brought together with clamps working from the bow backwards. The glue is inclined to start dripping on the floor and it is useful is you have someone to hold up the inwale at the other end. I didn't (her mother wouldn't let her go near the epoxy) so I just balanced it on the open door of a cupboard beside the boat. The inwales were held fast to the boat using 4x18 countersunk stainless steel screws. probably they are not needed - the epoxy is good enough to hold the wood - but I left them there after the epoxy cured anyway.

You need a lot of clamps for this job. They can come off after 24 - 36 hours depending on the curing temperature. There is a lot of cleaning up to be done as well as the epoxy drips down while you are clamping. Most of it ends up in the bin. After it has cured and you have removed the clamps you can tidy up the rest with a heat gun or a sharp blade. For the Stornoway 12 the inwales on both sides took me about 8 hours.

Inner Stem

The inner stem is laminated from six 5mm x 35mm strips of Douglas Fir.

First the curve is drawn onto a piece of wood, in this case a flat sheet of MDF. The strips are bent around the curve and clamped onto blocks of wood placed along the curve. Naturally the MDF has to be covered in a plastic bin liner and the blocks have to be covered to prevent the inner stem from sticking to the template.

Even 5mm strips can break when bent around a tight curve, so I heated them over some boiling water (in that old Le Creuset we bought when we got married - knew it would eventually come in useful) to allow them to bend more easily. They say you should steam the wood one hour for every inch of thickness. I only got 15 minutes before herself wanted the hob for lunch but it was enough.

All the wood was wetted out with neat epoxy and allowed to soak for a couple of hours. Then the strips were glued together lying flat with thickened epoxy before being presented to the template. I clamped the upper end together first and then went around the curve as shown. A lot of clamps are needed. The laminated wood has to be banged flat to the MDF as well to keep the pieces flush.

Given the tight curve in the wood I left it for two days before I took off the clamps otherwise the wood might spring out of the correct curve while the epoxy was only partially cured. When the clamps are removed the edges of the piece are covered in epoxy which has to be shaved off.

Finaly the stem is shaved down into a triangular profile to fit into the front of the boat where is is sat into a bed of thickened epoxy. The planks are then screwed to the stem before the epoxy cures to hold them firmly to the stem. Each plank was fixed with two 25x5 stainless steel screws.

Construction timber

The internal structure of the boat, gunwales, runners, mast and spars will be made from Douglas Fir. The wood was cut from a log in Clonmore sawmills near Tullamore, Co Offaly. The picture above shows the automated bandsaw which can take the massive log and churn it out in the form of 5 meter matchsticks if you want. The picture below shows some of the wood getting spat out at the other end of the machine.

This rough sawn timber was then taken to a joiner in Toomevara and cut up further, to specifics given in the plans and planed smooth. When I put it on the car in Clonmore I thought the roof rack would break with the weight of it. By the time the guy in Toomevara got finished it weighed a bit less.

Scraping smooth and taping outer seams.

All longitudional seams on the boat are now filled and scraped smooth. However, around here, anything left lying around for more than 10 minutes is likely to be converted into a house of some sort.


Seams were scraped smooth and sanded lightly. Then the entire outside was painted with epoxy and 50mm tape was laid along the seams as below.