Wednesday 1 May 2024

Resin Clear Coating

Having stripped the components that are not part of the hull, I now needed to clear coat them all with resin.

The rudder cheeks looked like this.


And here are the drop boards, tabernacle, and the centreboard patches.


I will give them two or three coats, sanding in between.

Like the last post, tedious and time consuming, but important.


Hull & Centreboard | Patching

When stripping the paint from the bottom and sides of the hull with the sander I inevitably sanded through the fibreglass to bare wood in a few places.

The same thing happened on the centreboard.

For this reason I am going to strip the topsides with paint stripper only, now I know how effective it is.

So, fibreglass cloth patches needed to be applied over all the bare spots.

I marked them all up with bits of tape so that I didn't miss any. As here.


And here are a few on the centreboard too.


I then applied 'glass patches with clear resin. Here they are on the bottom.


A second coat of resin filled the weave, and when fully cured I faired them smooth and flat with the sander.

I want the new paint to have the best possible substrate, and for the hull to be as strong as it can be. So although tedious and time consuming, this preparation is really important.

Centreboard | Pendant & Pivot Pin Holes

As mentioned in a previous post, I decided to reinstall the centreboard pivot pin and pendant while the board was out of the boat.

The first task was to drill out the holes in the keel sides for refilling them with thickened epoxy.

I marked up the hole on both sides of the keel. This is the starboard side.


I decided to increase the diameter of the epoxy plugs to 25mm.

Next I drilled out new holes. Here I am drilling the hole in the port side, using the drill guide clamped to the keel and a 25mm Forstner bit in my little cordless Bosch drill.


This is the new hole drilled out on the starboard side.


That will provide a much larger area of cured resin for drilling the new pivot pin holes.

Then I did the same thing with the centreboard pendant holder. This is the marked up board, with the hole enlarged from 20 to 35mm.


Then I set up for drilling the new hole with the drill guide and the board clamped in place, like this.


This the new hole, drilled out with a 35mm Forstner bit.


That will allow for a much bigger opening to hold the knotted end of the pendant.

The access hole for the pendant will also need to drilled, filled and redrilled for the same reason. This is it before improvement.


I then filled the starboard keel hole with thickened epoxy, using a piece of thin plywood covered with plastic tape clamped inside the trunk, and a plastic card and a piece of ply clamped to the outside.

I squeezed epoxy into the hole while gradually moving the plastic card up the outer keel side before clamping it in place. Like this.


Next I set up for filling the enlarged pendant knot hole with thickened epoxy, with a plastic squeegee clamped under the board to seal it. Like this.


And here it is filled.


When fully cured I drilled a 30mm hole with a Forstner bit and the drill guide, as here.


Now it was time to tackle the pendant access hole, so I set up the board with a new drill guide which I got specifically for this task. Although it would have been useful for a lot of things, had I known about it!

Here it is taped in place.


The guide has six bushes to guide the drill bit - 4, 5, 6, 8, 10, and 12mm. Two pins (nails) drop through opposite corners of the plate to allow it be centred exactly over the edge of the board.

I drilled the hole out to 8mm and filled it with thickened epoxy, and when cured I then drilled a 6mm hole with the assistance of the drill guide.

That worked well. Here are both the new pendant holes after drilling.


That looks a lot better than the original holes, although I did closely follow the build manual's instructions.

Now came the time to drill the new 10mm pivot pin holes in the keel.

This time I used the new drill guide simply held in place with a pair of spring clamps.

Here I have just drilled the new holes from the port side, right through the keel and out the other side. It was an easy way of ensuring that the holes lined up exactly.


And they did. I pushed a 10mm bolt into the hole and it slid easily out the other side.

Here it is, viewed from the port side.


However, somewhat bizarrely the bolt emerges on the starboard side in a different place to where I marked up the centre of the hole. This is it.


I was somewhat alarmed at first but remembered that the initial mark up of the holes and their centres was done by eye, and the drill guide made sure that the holes are in line and perpendicular.

We will find out for sure when I test fit the centreboard, which will be soon.

And that's the new holes all taken care of ... hooray!

Stripping Paint

It was time to remove the paint from the various components which had been removed from the boat.

I started on the drop boards. I tried using paint stripper but quickly realised that there was no real need, and switched to the sander and P80 grit, as here.


That didn't take long.

I used the sander on the centreboard too. I had to also use stripper on the curved surfaces, and it turned out well. This is it.


This is the paint stripping kit.


I am using a pair of Bahco scrapers, which are very effective. One bucket of water is for washing the scrapers, and another is for sponging the surfaces clean.

The outside of the tabernacle was easy to sand, but the inside had to be stripped. I used plenty of stripper left for 45 minutes, and then scrubbed the paint off with a stainless steel scouring ball. Like this.


That worked well. Here is the cleaned up tabernacle.


The rudder was next. I only used stripper here because of the many curved surfaces. It worked well. Here the rudder is partly stripped.


I stripped underneath the bottom plate too.


Encouraged by success, I then used stripper to remove all the paint from around the transom, as here.


The companionway slide came next. Here it is being stripped.


And here it is with just the front and rear faces left to do.


Lastly I stripped what little paint remained on the bottom of the keel. I masked off the transom to protect the varnish, and the centreboard slot to stop stripper from falling into it. Like this.


We're getting there. Again.


Portlights & Centreboard | Removal

I started work on the boat again at the end of March, beginning with the removal of the three remaining portlights which I didn't have time to do before we left on our travels in January.

This started well and the first two came away from the cabin sides easily, as here

However when I came to the final (port, rear) portlight it was a different story.

It absolutely refused to budge, and I had to prise it off with an old screwdriver. It left a ridge of hard, dry caulk inside and outside the cabin. Like this.


That is going to take some removing!

I wondered why this had happened and remembered that I used an old tube of caulk when I started on the portlights, and soon ran out so had to buy a new tube. The new stuff was fine - it cured to be soft and flexible and easy to remove, but the old stuff was obviously past its best.

This is the caulk I am using.


Lesson learned - never use old caulk! It can't be trusted.

I wanted to remove the centreboard while it was accessible again, for three reasons.

First, I had no reason to believe the the paint on the centreboard would not blister just as all the other white paint had done. So I really had no choice.

Second, I was not happy with the pendant fitting when I installed the board. The hole through the board was very small and the knot at the end of the pendant had to be forced into place, and I was not sure I had heat-sealed the end properly.

Third, the centreboard pivot pin through the keel sides had a very thin layer of thickened resin around it and I suspected that it might be a weak point, given that it would be subject to considerable forces.

So this was an opportunity to put these things right.

First I drilled out the resin plugs which hold the pin in place. This is the plug on the port side.


You can see that the ring of resin around the pin is very thin.

The pin resisted efforts to knock it out so I used a heat gun to warm it it up, which worked. Then I pulled it through with a pair of pliers. Here they are.


I knocked it through with a screwdriver which then held the board in place, like this.


I secured the end of the detached pendant so that it would not fall into the centreboard trunk.


And here is the centreboard out of the boat and the bench.


This is the hole for the knot in the end of the pendant. You can see that it is quite small at 20mm.


So I am going to make it much larger, so the pendant will be secure.

This is the hole for the pivot pin. It has plenty of resin around the pin, so it does not require further attention.


Next job is stripping more paint ...