The bottom of our Core Sound 17 Mk3 has now been painted!

I've now drilled the hole in the centreboard for the uphaul line. Once this was sanded and cleaned I coated it with unthickened epoxy.

In preparation for the undercoat, the hull was sanded with 120 grit paper. I didn't want to be too aggressive along the chine edges, so I sanded the edge by hand. I also sanded the keel strip by hand.

While sanding the starboard side of the hull I noticed a few areas with amine blush, so I had to scrub this side to remove the wax on the surface. Hot water, detergent, a scouring pad, and elbow grease took care of the amine blush.

The next day I was able to finish sanding the bottom of the boat with 120 grit paper. Sanding dust was wiped off the hull with a damp cloth.

The bottom of the hull was coated with Aquacote high build epoxy undercoat, from Boatcraft Pacific. The undercoat was tinted with black epoxy pigment. This should work well with the British Racing Green topcoat. To avoid runs, the first layer was a relatively thin coat, creating a base for the subsequent thicker layers.

I'm only painting to the bottom of the sheer strake while the hull is upside down. The topsides will be painted once the rest of the structural work is complete.

The two-part undercoat is mixed in equal quantities, and then left for 15 minutes to activate before rolling it on to the hull. I fell into the pattern of using half of a batch, and then mixing the next batch before using up the rest of the previous one. This was pretty much in line with the pot life of the mixed undercoat and the needed activation time for the next batch.

The second day of undercoating saw two more somewhat thicker coats applied to the hull. One side of the centreboard and the rudder also got two coats. The undercoat was rolled over a smaller area, to give a thicker finish. This will be sanded smooth once it has cured. The bow and the transom both received an additional coat, to fill along the fibreglass cloth edges.

The other side of the centreboard and rudder were undercoated this morning. Then the transom and the bow had another coat around the edges, to fill along the fibreglass cloth edges. Later in the afternoon the second side of the centreboard and rudder both had two extra undercoats, as did the bow and transom.

Now that the high-build undercoat has been applied, I have to give it at least 24 hours to cure before I can start sanding. After curing for a couple of days, the undercoat was ready for sanding. I started with 80 grit, followed by 120 grit and 240 grit paper.

The back of the aft locker hatch was sanded and epoxy coated, as was one side of the rudder.

I drilled through the epoxy bushing in the rudder blade, for the pivot bolt. I am using an O ring to stop the wingnut coming off the bolt

I started installing some of the hardware for the centreboard uphaul, so that I can lock it in place when the boat is turned back over.

Once the boat has been righted I will support the centreboard under the hull, and then remove the hardware prior to fairing and painting the cockpit.

The eyestraps are through-bolted.

The two cheekblocks are through-bolted with 50mm long 4mm stainless steel bolts.

I have made the cap for the centrboard pivot out of two pieces of 12mm ply. One has a hole drilled out of the centre. The end of the pin will fit into the hole, with the solid piece covering the hole.

The keel strip and surrounds were hand sanded.

The rudder blade and centreboard were both sanded with 80, 120, and 240 grit paper.

The fibreglass tape that was folded down from the hull into the centreboard case was sanded to remove the rough edges.

The other side of the aft locker hatch was sanded and given another coat of epoxy.

I found amine blush on the other side of the rudder assemby so it had to be scrubbed with hot water and a scourer pad to remove the wax before giving it another coat of epoxy.

The rudder blade and centreboard both had one side painted with Aquacote paint. I'm using British Racing Green for this boat. A combination of rolling and then tipping with a brush seems to give a good result. After an hour I gave them another coat, diluted with 15% water to let it flow out. I didn't tip this coat, but I should have, as the surface didn't finish up as smooth as I want it to. I will have to sand tomorrow.

A final coat of epoxy was added to the after locker hatch and rudder.

I sanded the painted rudder blade and centreboard with 600 grit wet and dry paper

Sanding was necessary because of the stippled finish on the previous coat, and also because of the time elapsed since that coat.

It is suggested that the British Racing Green tint in Aquacote should be power mixed for five minutes before painting.

For the first batch of paint I mixed 500 ml of paint with 75 ml of water, and 225 drops of the Cross Linker catalyst. This was enough for two coats of the bottom and sides plus the centreboard and rudder, with the remaining paint being poured through a strainer back into the tin.

Rather than using a roller and bristle brush today I started using a foam brush, which gave a great finish, so I will keep using these.

The best place I could find for foam brushes was an art supply store. I bought them from Art Shed, in Moorabbin.

To try and stop runs on the vertical surfaces, I used quite thin coats, which means I will have to do more of them. I gave the boat four coats today. Each coat took the better part of an hour.

The following morning I sanded the paint with 600 grit wet and dry sandpaper. The sanded surfaces were wiped clean with a damp cloth. The entire hull was wiped down three times, with fresh water in the bucket between passes.

Two more coats of paint were applied to the hull today, using a 50mm wide foam brush.

The other side of the rudder blade and centreboard received three coats today.

The other side of the rudder blade and centreboard were sanded with 600 grit wet and dry sandpaper prior to repainting.

The hull was also sanded with 600 grit wet and dry sandpaper.

I spent some time sanding vertically to try and reduce the ridges from the horizontal brush strokes. The hull was wiped down with a damp cloth three times to clean off the residue.

Another two coats of paint were applied to the hull, bringing the total to eight coats. For the coats today I used a 75mm foam brush.

I wasn't happy with the finish on the sides and transom, so I sanded them flat with 240 grit paper, and repainted them. This time I didn't dilute the paint with water, and finished each section with vertical strokes to stop any runs. An extra six coats on the sides after sanding resulted in a much better finish.