Stringers

Four hours of work today, all devoted to the stringers. The design calls for stringers which are beveled lengthwise according to the hull section geometry. Such bevels are well described in the plans, but we had to make good use of some trigonometry (the tangent comes of help here!) and some "tests" to cut them right, using the trustworthy circular saw. By the way, we discovered that the tilt angle gauge on the saw is not very reliable... This has been a noisy working session!
Here's the setup: on the left is the plank being split in two lengthwise, on the right is a plank whose only task is to keep the saw base stable.

And 60 meters (200 feet) after, here are the 12 small stringer sections (along with the beer to celebrate the milestone):

We still have to make the larger stringers for the main hull keel which calls for thicker lumber. Here we are at the end of the (heavy) scarfing work with the electric plane:

Total work time to date: 38 hours

Long planks

Here are the scarfed planks. The scarf joints turned out quite crude with several voids, but the resin cured ok. We'll fill the voids in the joints when the stringers will be glued on the hull panels on the flat.
Those planks will be split in two lengthwise cutting the designed bevel with the circular saw. The two longer planks on the right will become the top and middle stringers of the main hull, while the four on the left will become the stringers for the floats (8 in total). We still have to make the thicker stringers for the main hull bottom...

Scarfing lumber

Today has been quite productive: we managed to work 5 hours at the boat. The new lumber has been delivered in the morning so we devoted the whole day to the stringer scarfing. The building instructions leave the builder free to choose between several options, including simply butting the stringers on the hull panels. Anyway, we decided to scarf because in this way cutting the bevel with the circular saw will be simpler and faster.
Scarfing is not easy! We decided for a 6:1 bevel and used the stairstep scarfing method with an electric plane, finishing with a Surform and an electric sander, but the scarfs were not perfect. However, since the requirements are not that strict, and knowing the gap filling properties of epoxy, we think that the joints will be sufficiently strong.
Here is the stack in the middle of the planing effort

and here are the (almost) finished scarfs

At the end of the day, we prepared 100 g of resin thickened with a few tea spoons of microfibers, aligned everything and put some weight over the glued joints. The temperature in the shop was quite low (14 degrees C) but the epoxy is sandwiched in lumber here, so it should be no problem.
We'll see if it has cured overnight!

Total work time to date: 34 hours.

More lumber

Back to the lumberyard today, to buy 8 more 2 cm thick planks for the stringers, since there's little doubt that the figure in the plans (200 feet = 60 m of 2x3 cm stringers) is underestimated more or less by a factor of 2. We selected the planks one by one and we expect those to be delivered by tomorrow.

Lumber

After a long wait, the lumber was delivered so today we worked 2 hours to rip the various pieces using the circular saw. First discovery was that the 1.5 inches (4 cm) thick planks are HEAVY. Based on the published densities for the fir, the forward aka system should weigh 35 kg, and the aft one about 25 kg. We didn't weigh ours, but I can assure that they do look robust. We could not avoid a few knots here and there...

We cut to length, labeled and set apart all the aka sections. Then we moved to the 3/4 inch stuff to rip the stringer material, and discovered to our dismay that the bill of materials is wrong by a factor of about 2 on the quantity of 2x3 cm (3/4x1-1-1/4 inch). Most probably, the designers did not take into account either the longitudinal stringers or the ones used to increase the rigidity of the hull sides. The result is that we'll have to order some more 2 cm thick stuff... Oh well.

Total work time to date: 29 hours

Press stop

The lumberyard is way late in delivering our order, which should be ready any time now: we ordered the timber for the stringers as well as for the akas. In the meantime, we have received the first batch of epoxy resin with a bag of natural microfibers for thickening. Hopefully, next saturday we will be able to work again on the boat project.