Originally my plan was to use two 8 mm bolts + nuts (near the bottom) to hold the two halves of the dinghy together. I already drilled the holes.
Bolts and nuts, however, can only be connected/tightened if the two halves are perfectly in line. In the water that could be very difficult.
So I decided to use rope instead. The first tests are sucessfull:
I will also run an extra line under the dinghy from bow to stern to pull the two halves together. This line will put quite a lot of stress on the bow so I put some carbon on it (the black stuff on the bow and at the waterline).
Made some progress on the boom. The outside has been faired. More or less. I will probably stop at this point because I hate putting even more filler (=weight) on the boom. But maybe I will change my mind again later …
The false bottom has been cut and I decided where and how to install the reefing points. The edges of all holes were reinforced by removing some foam and replacing it with carbon/epoxy.
During the laminating process I decided to reduce weight (and cost!) by gradually reducing the laminate thickness towards the front and back. The heavily loaded vang area still has the original laminate thickness.
The boom still needs a lot of work. I have to install a full length “false bottom” to connect the sides and stiffen the structure. I have to think about hardware options and the reefing system. Last but not least, I have to fair and paint the entire thing.
After finishing the dinghy I will probably focus on the boom again.
The kick-off for the new project was gluing and shaping a wooden core for a carbon rudder stock. It is quite a beast at almost 3 metres.
I also made a mold (rough) for a carbon boom.
The boom will (hopefully) look something like the one I saw in Guernsey recently.
My dream has always been to have a good storage space for a reasonably sized dinghy. The current solution is this foldable design that should fit in the cockpit of the mothership. After it is finished I will saw it in half and put hinges in the middle, on the deck.
The owners of a big self-built catamaran asked me if I could help them bring their boat from The Netherlands to Portugal. A great chance to escape from the epoxy and dust! There wasn’t much wind but it was nice to visit new harbours (took a lot of pictures of interesting boats) and see some dolphins:
A couple of weeks ago I used some leftover pieces of foam to make two small tables. I put a thin glass laminate on both sides of the foam and the resulting panels were stiff enough to be used as tables.
I am not sure yet what I will do with these tables (garden, boat?). I just wanted to use the leftover foam.
Ofcourse, this isn’t a very efficient way to make a table. I could have used a piece of 18 mm plywood instead. That would have saved me a lot of time. But, so the sandwich theory goes, at least I saved a lot of weight. But did I really?
The tables weighed 3,3 and 3,8 kg respectively. The edge of the heavier table was filled with glass/epoxy. The edge of the lighter table was left untreated (at least for now).
How does this compare to a solid plywood table of similar thickness (18 mm)? The tables were 82 x 57 cm. Assuming a density of 500 kg/m3 (average Google result for okoume plywood) a plywood table would weigh around: 0,82 x 0,57 x 0,018 x 500 = 4,2 kg, The plywood table would still need to be faired and painted. Let’s say the finished product would weigh around 4,5 kg. So the difference is 1,2 and 0,7 kg.
Personally I think that’s quite a big difference (in relative terms). For weight critical applications (e.g. boat interior) I would certainly consider swapping plywood for foam sandwich. I would, however, reconsider the edge treatment. Filling the edge with glass/epoxy added an enormous amount of weight. That was a bit stupid.