Filling and Filleting

Time for all those holes to be filled, sharp edges and corners to be smoothed and shaped in preparation for fibreglassing. Also the decision on weather to flip it over now or mostly finish the bottom first needs to be made. Flipping it over will be no easy task, also with the height limited in my garage once the cabin is on means I will be at least painting below waterline before flipping it over.

I have run a router down the keel chines with a 38mm bit giving a 19mm radius. There is a trade off with the chine radius. On one hand a large radius will be less prone to damage and easier to fibreglass and perhaps help the boat tack, but on the other hand a smaller radius will give the hull better 'bite' in the water when going up wind.

At the Bow I have used a 50mm router bit which has resulted in a near perfect radius at the bottom where the bow is about 50mm across. Again there are trade offs with bow radius. My preference is for a more blunt bow shape. In this case where the hull is very narrow, it is actually quite hard to get a sharp bow, as the sides of the hull converge at a very small angle.

This fillet for the inner wing is huge. Here I am part way through making it, I used about 3 litres of west filleting blend filler and used a compact disc for the radius. I have often thought about how strong this part needs to be so I haven't skimped in this area.

Bottom Covered

The bottom of the first hull is now covered with ply. It has for the most part been quite easy, I got into a bit of a rhythm with the process of marking the wood, mixing epoxy, coating, gluing/screwing. The hardest part was the sheet at the bow on the inner side where there is the most shape.

Another tricky job was making this curved plank. I had to scarf the lengths allowing for the curve by marking the scarf lines with the lengths placed at the desired angle then sanding to the marks which resulted in the angle of scarf changing across the joint. It worked well.

One milestone was the removal of the holder for the bow bulkhead which up until now had been doing a very important job. But has to go to allow for trimming and shaping. You can see it is missing in the top photo.

Another handy tool

Here is some more pics of the planking.

Here I'm using the scissor jack again to line up a sheet.

All of this work needs a lot of screws to hold the sheets on while the glue sets and would be much harder without the use of this handy tool.

This is just like a cordless drill but without the troublesome battery, lower RPM and more torque than a standard power drill. 12V? 18V? try 230V, works way better and never goes flat :) The torque settings are great for putting the screws in fast.

Getting my plank on

Finally I get to start closing in the hull. One last look before it gets covered. This pic really shows the shape of the boat very well. I have found two new things that are taking up more building time, staring and daydreaming :)

I have prepared one side of the plywood sheets by coating with epoxy, sanding and coating them again. This gives a very nice smooth clear finish to what will be the interior of the boat.

You can see in this picture I am lining up the second sheet on the outside of the port hull. I am using a car scissor jack to have good control over the location of the sheet to butt it against the first sheet. Once in place, I put a few screws in and then use a pencil to mark the location of stringers and framing on the interior side of the sheet. Then I remove the sheet to prepare it for mounting.

Using the pencil lines as a guide, I cut out the shape (slightly oversize to allow for trimming), drill the holes for the screws and sand where the stringers and framing will be.
Then I apply epoxy to the sanded areas and to the framing/stringers then thickened epoxy glue over the top, then screw in place with a lot of screws and tidy up the squeezed out glue. Then the next day I remove the screws and get ready for the next sheet.

Inspection ports

I decided to put these in while access is easy.

I used this hole cutter which attaches to a drill. Then sanded the edge and applied epoxy. Once cured, I used marine sealant and screwed into place with stainless screws..
One port is in the forward bulkhead below the storage area and one is in the stern. Both areas serve as watertight bouyancy. With this boat, I want to be able to regularly inspect all areas.

Planking Prep

With most of the stringer fairing done, a few more jobs need to be done before planking begins. One of them is butt blocks for joining the panels. I will scarf the keel and inner wing but I have decided against scarfing the large side panels due to the size as I am building this all by myself so full length side panels would be too hard to manage. The butt blocks are made from the same 6mm Okume as the panels which I cut on the table saw which allowed me to quickly make a lot of them straight and identical in width.
I used a router to take the majority of wood out and also use a power file to tidy it up.

Then simply glue them in place. I will sand them as I go around the hull double checking everything is fair.

Fairing Stringers

Now that the stringers are all on, they need to be faired so that the outer surfaces will line up with the planking, and give a good surface for glue adhesion. For this I am using a combination of electric planer and belt sander. Checking as I go with a steel rule.