Painting - First Undercoat

Today the wooden boat disappeared under the first coat of International Pre-Kote undercoat and is now white. I had to stop periodically to add a little thinners to the paint because the temperature was well over 30 degrees C and the paint wasn't flowing nicely. While paused I took this photo.

 

 

You can see the remaining brown epoxy coating on the plank above the newspaper. The two piebald planks above that show the remains of a coat of AquaCote that I put on over the epoxy but ran short of by one plank! AquaCote is a water based epoxy high build primer. It does all the right things, it's waterproof, dries hard, builds a thickish layer and sands easily. What it doesn't do is to flow out level so it holds brush marks or an orange peel effect if it is rolled on. Maybe I am not clever enough a painter to avoid these problems. I used it because I had it left over from a previous job and to fill the hollows in the epoxy coat under it. It did fill the hollows in the epoxy but it took me a day and a half to sand it back to a flat surface without grooves left by the brush. Never again!

 

Here is the other side completed. The International Pre-Kote flows out nice and level and will only need a gentle rub with some 180 or 240 grit paper before it gets a second coat.

 

 

The dog likes the concrete floor because it is relatively cool.

 

 

 

Ballast Tank Inlets

I have begun sanding the epoxy coating. First with coarse (80 grit) paper on the flat areas to remove the tops of the hills, bubbles caused by air coming out of the timber, dead insects, etc. Miraculously I didn't have any major runs to deal with. After the 80 grit I will change to 120 grit and go over the corners carefully so as not to remove all the epoxy. Then another pass over the whole hull with 120 grit.

While sanding the garboard plank (next to the keel) I sanded around the inlet to the water ballast tank and thought it might be worth a couple of photos. First  an explanation: the Able has two water ballast tanks in the bottom of the boat on either side of the centreboard case. Each tank holds about 45 litres of water providing about 90 Kg of ballast. The tanks are filled after the boat is launched through two holes in thebottom of the hull. As the water enters the air is pushed out through a vent pipe inside the hull. When the tanks are full the vent is closed so the water cannot run out of the tanks. When the boat is taken from the water on its trailer the vent is opened and the water runs out through the inlet holes. If the water ballast is not neededm boat already heavily loaded with crew and/or camping gear, the kept is kept closed preventing the water flowing in. Well that's the theory, I hope it works out!

Here is a photo from outside the boat. The result of the coarse sanding can be seen around the hole; the shiny areas are untouched.

 

The hole in the plywood plank is 32 mm daimeter with a small chamfer around the edge. The white tube is a plastic plumbing fitting with a 25 mm hole through it. To improve the glue bond to the plastic I put the fitting in my metal turning lathe and cut a shallow fine pitch screw thread on the outside. Then, after painting the edges of the ply around the hole with unthicked epoxy, the tube was screwed into the hole with plenty of thickened epoxy around it. After the epoxy set the tube was trimmed flush. The tube will protect and seal the edge grain of the hole in the ply.

 

On the inside of the hull, photo below, things are not so tidy! The back of the tube butts up against the inner part of the keel and the spaces either side of it will be filled with thicked epoxy to provide more support for the tube. The front of the tube will be cut away flush with the inside of the plank so that all the water can drain out. This will be done after the boat is turned over.



First Coat of Paint

It doesn't feel like 6 weeks since the last entry on this blog but the calendar doesn't lie. I have actually been sailing for half that time; two weeks in the Great Sandy Strait, two 2 day outings with the WBAQ guys at Caloundra and a day out at Wivenhoe. Another week spent catching up on chores at home. That leaves two weeks spent working on the boat.

I haven't put anything on the blog because sanding and filling is such a tedious process and is not very photogenic! However today I gave the whole outside of the hull two coats of epoxy to seal it. I started early in an attempt to avoid the worst of the heat and that helped but the epoxy was going off pretty quickly so I had to mix quite small batches. I used Boat Craft Pacific epoxy with the standard hardener mixed 2:1 with no thinners. This is sticky stuff to paint on, it is more a case of spreading it out thinly! The first coat took about 4 hours followed by a short break for a snack by which time ir was ready for the second coat, just slightly tacky to the touch. The second coat went on more easily because the epoxy flowed a bit better over the first coat. Another 3.5 hours and it was done.