Upper Hull | Final Coat Status

I mentioned in a recent post that I had contacted the guy at BoatPaint UK where I now source all my painting products. He has been really helpful.

I asked him what he thought about having low relative humidity in the workshop, and how it would affect paint behaviour.

He said he had never heard of it causing problems, and didn't think it would matter too much.

Grateful as I am for this advice, I am sure that it would be a bad idea to ignore the very clear Epifanes instructions on this matter i.e. do not apply paint when the relative humidity is less then 50%

Knowing my luck, I would be the first to find out that it really does matter!

Here is the dilemma, shown by the readings on my thermometer/hygrometer.

It is now so cold here that I have to heat the workshop to make it habitable. The top screen shows that the working temperature is now 22°C, but it fell to 10°C overnight which is the lowest recommended for painting.

Heating the workshop causes the relative humidity to fall to 30% or less (lower screen), and this is where the problem lies. I can't risk a flawed finish. I really don't want to have to repaint the final coat!

We are going to the southern hemisphere for the whole of February, and the chances of the weather improving before we leave are very low.

So the final coat might have to wait until March, which is very frustrating. I really thought painting would be complete by Christmas, but not for the first time have I been over optimistic!

I will complete what other tasks I can in the next couple of weeks.

Onwards and upwards!

Companionway Hood & Seatback lockers | Glossing Interiors

I started to apply gloss to the interior of the companionway hood some time ago, when I started painting the upper hull.

It has to be done in two stages - the top and bottom in the first, and the sides in the second.

The top and bottom faces require a long handled 6" roller to reach the front of the hood.

This is it.

It is very effective. No one will be able to see the interior of the hood so I made no attempt at tipping out the gloss. A rolled finish will suffice.

When the top and bottom are fully cured I will gloss the sides.

I was initially worried that glossing the seatback locker interiors would be tricky, but a bit of thought and ingenuity made it straightforward.

I used a small brush with the handle cut off short to paint the inside face of the seatbacks. They are not visible so the finish is not critical.

Then I used a 6" roller to paint the visible faces i.e. the front and back walls and the floor, tipping out with a soft brush.

Here is the tool set.

This works quite well. At time of writing three coats of gloss have been applied.

It is taking a long while for the paint to fully cure, due to overnight temperature drops, but the finish is going to be excellent.

Here is a view of the port locker interior.

I think it is an advantage that the final coat has not yet been applied to the cockpit decks. It doesn't matter if I drip paint onto it!

Main Sheet Block Support Pad | Applying Primer

The pad that I made to receive the main sheet ratchet block had been sitting on a shelf for months, so I used some left over primer to paint it.

Here it is.

Also in the pic are six small square pads which are required to fit the ventilators. See early posts for their purpose.

Dorade Boxes | Priming Interiors

While waiting for a decision on how to proceed with the final coat of paint on the upper hull I started work on the remaining parts of the boat.

The first was to apply primer to the Dorade box interiors.

To do this I initially decided to paint them through the ventilator hole in the cabin roof. I devised a brush with an extra long handle to do so.

Here it is.

It didn't work particularly well, so I switched to priming with a 6" roller through the inspection hatch holes.

This is it.

That worked much better.

It's impossible to take a photo of the interiors, so I won't try.

At time of writing the fourth coat has just been applied. One more and they will be ready for gloss.

Upper Hull | Final Coat Hiatus

I gave a lot of thought to how I should approach the fifth and final coat of gloss on the upper hull.

Assuming that I would be able to achieve a good finish, I wanted also to minimise dust interference.

This is of course impossible to eliminate in a busy shared workspace with not very much room.

I knew that I should not try to clean up shelving, stored parts, cupboard surfaces and so on. To do so would just redistribute the dust, so I just left it all well alone.

The floor was a different matter, however. It is always dirty, with mud and leaves from the garden. And the non slip mats are full of dust after months of work on the hull.

So I got rid of the mats, and vacuumed the floor thoroughly.

Then I washed it with a mop and bucket. This is them.

I did it twice, to get it as clean as possible.

I will do it again immediately before the final coat, to lay any dust that has formed. This is a trick that I picked up from a CLC video on how to varnish a kayak. Keeping the work area damp underfoot stops dust from rising.

Now, it has turned pretty cold here in the UK in recent weeks and I was thinking about temperature in the workshop when I am painting.

It gets warm very easily using a radiator to heat the room, but I was a bit concerned to note that the relative humidity drops a lot.

The technical data for the mono-urethane gloss states that it should not be applied at lower than 10°C, or less than 50% relative humidity.

This is what my thermometer / hygrometer is showing now.

I have a temperature of 21°C, which is fine. But the relative humidity is only 35%. Which is not fine.

The air is very dry, which will cause the paint to 'flash off' quickly i.e. its solvents will evaporate rapidly leaving dry edges and brush marks.

We definitely do not want that to happen! I don't really know what to do, so I have emailed the guy at BoatPaint UK who has been extremely helpful so far.

I may have to wait until the weather improves. In the meantime I have compiled a list of everything that needs to be complete before the boat can be moved outside again, and noted which tasks can be done in advance of painting.

This is the list.

There are just 21 activities left to complete, which is amazing! Those highlighted in yellow can be performed now, so I've got things to keep me busy.

I never really paid much attention to humidity before when painting. I'm so pleased I have at last realised how important it is …

Various Parts | More Wet Sanding

Before I packed the sanding gear away I thought I would prepare some of the remaining components for their final coat of gloss.

These are the drop boards and the companionway slide.

Here I am wet sanding the drop boards with a P400 grit.

And here I am doing the same to the companionway slide.

The tabernacle and the rudder still require several more coats, so they can wait a bit longer.

We're getting there!

Upper Hull | Taping For Gloss

When the upper hull had been fully wet sanded it was time to get ready for the final coat of gloss. That meant retaping all the rails.

So I used 3M 218 Fine Line to cover the edges and 3M gold Professional to cover any bare Sapele.

Here are the starboard rub and toe rails, ready for gloss.

And this is the transom.

Part way through preparation for the fifth coat I decided to divide the task into smaller, separate areas.

This was to allow me to take my time and not rush to get large areas covered all at once.

I would be able to concentrate more on the quality of finish rather than worry about the paint curing too quickly.

So I taped off the forward deck well, like this.

I divided the cockpit into the footwell and the decks, like this.

And lastly I taped off the cabin roof and companionway hood. Like this.

I think this will make the final coat easier to apply.