Bilge keels, strakes and various works

Sorry, guys! It has been a while….more or less two months have past since I’ve last blogged about the progress on my Ebihen. During that time there has been good family-time since the girls have summer holidays :-)), a week’s camping vacation in Friesland, a lot of work for my employer and some progress on the boat building project.

First of all: here’s another time-lapse. It starts at the moment where I was still working on the garboards, and it ends at the point where 4 strakes on each side and the bilge keels had been mounted. Click here to watch;

After mounting 3 strakes on each side, I took a photo (front to aft) from below the structure;

On the left and right side, both lockers can be seen. In the middle you see the aft support pillar in front of bulkhead nr.3. Mounted on frame nr. 5 there are two temporary support planks in the place where the floor boards will be; these will be removed after the next turning.

Here’s a nice picture of how all planks are fitted to the transom during the fitting stage. When ready to glue, the planks are held in place by screws.

Here’s the best help 🙂
Every now and then one of my daughters jumps in to give dad a hand. Here the youngest one is helping drill a hole in the device I made to copy the hull’s radius for the bilge keel.

The bilge keels are both made from a plank of iroko. On this picture the port keel can be seen. The inner radius has been sawed, the outer is still to be done. I’ve mounted both keels permanently with screws from the inside and epoxy glue.


After mounting both bilge keels on the 4th strake, I started working on the 5th strake. Here is a picture of how the boat looks now; both 5th strakes are mounted permanently, the starboard one still held in place by clamps as long as the epoxy is curing.

Before the 5th strake was mounted, there was some work to be done on the inside of the boat. With this strake the compartments below the side seat locker bottoms are closed permanently and the compartment below the front locker will have limited accessibility. only through small holes in bulkhead nr. 6.
The side seat lockers were filled with foam sheets.

So the work continues. Spirits still high, moral is good 😉


More strakes and some polyethylene

Since the last blog I’ve mounted 2 strakes, no.2 and 3 on starboard. The no.3 strake on port side is in place but awaits permanent mounting.

On this picture the third starboard strake is not yet mounted permanently
Getting the bow nice has proven to be very time consuming

It has taken up a lot of time getting the strakes in the right place, especially on the bow section. A lot of torsion is required.
The result until now doesn’t look bad, but I thinks some filler and some more sanding will be required to get the final shape 😉

Before the fourth strake can be mounted on either side, there are some spaces that need treatment. On the aft part there is a small volume of air below the locker bottom below the seat that becomes sealed, so I’ll have to make sure that the inside is epoxy coated. Something I forgot to do on the starboard side, and since the no.3 strake is already epoxied in place, treating the inside will be a project with a thin paint roller and a mirror…
On the front side there is a small locker that will remain accessible via two small holes besides the mast, but it seems to be better to use the room there is as long as strake no.4 is not in place.

The design of the Ebihen 16 has three large buoyancy tanks that need to be filled with some foam later on. I’ve found some sheets of polyethylene on to do that, and wanted to try out filling up a space with it. The room below the lockers bottom in the aft part seemed to be perfect to see how this works.

The room below the locker bottom is filled with polyethylene sheets

Another small project was shaping the plywood that will be mounted as a third layer on the backbone on the outside of the centreboard case. As they are mounted on the outside of the hull, they need to be streamlined.
To get a nice bevel I stacked four layers of plywood, the third backbone layers in the middle, and shaved the bevel. This is a technique that is used to join large sheets of plywood to get the proper length for making strakes. As I’m using the CNC cut plywood sheets, the strakes for my Ebihen are joined by gluing the precut form together, so this was a nice opportunity to try out this nice technique.


2nd strake and some steam bending

Just a short update….it has been a while.

Today, the starboard second strake was mounted permanently.

The piece near the bow needed some work, as the overlapping of the strakes is reduced to zero to make them flush at the point where the false stem will be mounted. To achieve this I’ve made a mold that enables me to gradually mill away up to 5mm depth of both strakes, so they end up flush at the end. Should look nice once all strakes are mounted….😉

Then there was the issue of the extra seat supports needing a trim. As the seat supports have a small radius at some point, the trims needed to be steam bent. A challenge Roel happily accepted! He manufactured a steam box and a boiling pan;

After some experimenting we managed to produce two trims by laminating 3 layers of 1mm thick mahogany on to a seat support.

Then we tried a single layer of 3mm thick, which also worked;

We’ve glued this one into place with the steam bending mold holding the trim in place while the epoxy cured. Looking good! Thanks, Roel!


The first strakes, the garboards, have been mounted! Or ar least they have been screwed in place, ready to be epoxy-glued.

I have been working for what feels like days on the first garboard to get a good fit. The strake needed to be shaved and sanded to get the right bevel so it makes a nice close fitting with the backbone. Also the backbone needed a treatment with planer and belt sander. And then there is the issue of joining the garboard with the stem…it involves a lot of torsion and tension. Finally I screwed it into place, accepting a small gap between garboard and back bone between the mould in station 9 and the stem. I’ll fill it up with epoxy.

The second garboard didn’t cost as much time as the first one, so getting that done only cost me one day.

I’ve not yet mounted them permanently as both strakes are going to need a bevel to receive strake nr. 2. For this they’ll have to be removed again and planed on the workbench before final fitting with epoxy.

Turning day

Today the boat was turned for the first time. It was a very nice and satisfying event! I invited some friends to help, and it turned out to be a pretty uncomplicated manoeuvre. Only at the end, as the boat was already on it’s new supports, there was the need for an improvisational sawing action; the clamp needed for turning was in the way of the rear support, so the support was modified. Problem solved 👍🏻😃

Preparing for turning

During the past few days I’ve been preparing for turn-day. But before that can be done there were many small tasks that needed to be done;

The false stem was laminated. The first picture is where I made the mould, the second is a dry run without epoxy to see how it goes, and the last picture is the real thing.

After the false stem was put in it’s form, I opened up the plastic sheet to wipe away surplus epoxy. That worked fine, but the bottom side couldn’t be reached, so there is a rather large “epoxy-beard” to be sanded away later…

These are the clamps on which the boat will turn upside down later on. The idea was stolen from Thanxx 😉

There were some joints that needed fillets before turning the boat. I decided to experiment a bit with adding glass bubbles to the epoxy glue; it is supposed to make the resin lighter in weight and easier to sand when cured. The first attempt was mediocre; I mixed in the maximum recommended amount of 25% by weight which created a rather difficult to work with substance. Maybe good as a filler, but not for making fillets. In a second go I tried 10% glass bubbles which seemed to work better; applied with a piping bag created nice smooth fillets.

And finally, today Loïs gave me a hand producing the first of two supports that will hold up the boat once turned over. Tomorrow the second one.

Turning-day cannot be far away anymore!

The last frame

Mounted the last frame today, the nr 5 half frames. To do so I needed to get the temporary spacing boards in place; frames nr 5 need these boards to stay in the right position as the epoxy glue cures. Before being able to mount the longitudinal spacing boards, the mould (station 1) between transom and bulkhead nr 2 needed to be mounted as well. Well, you get the picture; before being able to get one thing done, three other things need to be fixed first…

Here’s the pics;