Lets Go says me. Now, during the months of mental anguish and planning I jumped from using foam, to using balsa, even to strip planking in Kiri or Cedar. I the end I decided to go with DuFlex with a balsa core. I asked the designer for a upper hull section that was quite flat so that I could use a full sheet of 1200mm wide material as the first plank, it really appealed to me the thoughts of gluing 5 or 6 sheets together on the floor and then lifting them up onto the building frame, 1 or 2 screws and a heap of planking was completed. The Duflex boards are covered with 400gm of uniglass which means they will bend (with a bit of persuasion) around the slight curve of the hull.

One thing I did not really appreciate before I started was the flexiblity of building with 1200mm wide sheets - the flexiblity been that you can cut the planks up into any width you like - with real timbers you are restricted to the wide of the planks but with boards you just cut them up however you want them - so our first plank was 1200 wide - like a whole sheet - next one 300mm wide, then 200, 150, 80 - getting narrower as we approx the curve of the bilge.

How we did it

First 1200mm plank goes on, then progressively reducing in width as one gets closer to the curve of the bilge. You will need to add small blocks of timber or mdf covered with tape between the odd frame to ensure the planks fully line up. We stopped planking upwards before the actual curve. Then we started to work down from the centreline. The hard bit here is the first plank needs to curve through 90° or close to 90° over the distance of a few frames, (close to vertical on frame 0 and close to horizontal on frame 3 or 4) you just have to try and get it to do that, the first and second plank seemed to be the ones we had the most trouble with. Use a combination of clamps - screws bolts and creative language - you will get there. Now this area of the hull is where board material can really help. You can create planks of different widths - what I mean is planks with steps in them, the stern is very flat is very flat quite a few frames. A plank 80mm wide then reducing to 40mm wide part way along the hull works a treat, 40mm wide where the curves are but 80mm where the flat areas are. You end up with a lip shaped slot that you prgressivly fill with whatever width planks you can get to lie flat. It is best, of course, to do a bit of planking either side for the boat to reduce the strain on the building frame. Once the whole of the hull is planked get out your trusted sander and go over the hull knocking down all the bits of glue sticking up and the odd plank edge that is not dead flat. Refill any gaps with glue. Then resand and check for any small holes - refill any small gaps in the planks - no matter how small.

Fibreglassing

The external surface of the hull had to be covered with one layer of 750gm triaxial. Measure each piece out, overlapping at each edge and the centreline of the hull by at least 50mm. I built a over the hull scaffold so we could access the hull reasonably easily. A team of 5 persons worked well - we had 4 for hull one but got one more guy for the second hull. 2 guys either side of the hull - one high up and one lower down - the lower guys soon learns how to watch for falling resin, and one guy mixing resin etc. We started at the stern, wet out the hull surface, lay on your cloth and wet the sucker out with paint rollers. Depending on the weather you may have to get going pretty early, It was approaching the warm weather when we did hull 1 so we cracked into it at 6:30am and we were finished at 1:00pm - it got pretty warm. Watch for air bubbles, keep moving using a flat blade plastic scraper can help wetting out the cloth. I was very pleased with the end result.