Paint for Boat Cabin Interiors

A great deal of the work required to bring a GRP boat back to life is pretty mindless. Lots of sanding polishing and painting – and it takes a long time. But let’s put a positive spin on this – it gives you time to think, and one thing I have learned is that there is always more than one solution to the next problem. How to fit a bulkhead? How to get the best paint effect? Whether to use oil or vanish on the woodwork? How to renovate old Formica surfaces? Another thing I have learned is that the first solution is rarely the best. So time provides room for thought.

Throughout the renovation project I have given a great deal of thought to the cabin interior and I have

come up with lots of ideas – most of which I have had to reject on the basis of cost or feasibility. This boat is an early example of a westerly and also an early example of GRP. The building process in those days (1968-9) was to make a mould and pour Gel-coat into it. Once the Gel was pretty much set, the boat-builders would then lay layer after layer of GRP mat over it, soaking each layer in resin. In some places, more mat was added to provide strength and rigidity. The outcome was a boat with a beautiful mirror-like exterior and a pretty rough, industrial looking, interior. The ugly straw coloured interior would often receive a coat of gloss white paint to finish her off.

Well maybe taste was different in those days, maybe purchasers found the treatment attractive. To my 21 century eyes however, the interior of the Westerly Nomad cabin is less attractive than the inside of a gent’s toilet on a bus station.

First question has to be why do I find this so unattractive? Second question – what can I do about it? Well, let’s face it – various layers of chopped glass fibre mat laid unevenly can never be attractive. The whole surface is lumpy. In some places where additional mat has been added, you can actually see the fibre – glued to the surface like a bandage. When you add gloss paint the surface sparkles randomly. It is as if the light accentuates the unevenness of the finish.

Later Westerly’s had foam backed vinyl head-linings attached to marine ply templates screwed to the cabin roof but they too had their problems. Over time, the foam deteriorated to a fine black dust and the glue failed leaving many owners with a problem that be came known as ‘Westerly droop’. Sagging vinyl isn’t attractive and today the cost of replacement foam backed vinyl is exorbitant. I didn’t want to spend the money – and anyway, I’m not prepared to invest in a solution that seems not to work.

Looking at brochures for expensive modern yachts, I was attracted to an idea of using  regularly spaced wooden lats along the cabin roof to give an impression of  a wooden yacht. The lats maybe four inches (10cms) wide and about a quarter-inch (6cms)  thick  run the length of the roof and between each one there is maybe a three or four inch gap. They seem to accentuate the length of the cabin and they provide a handcrafted kind of warmth to an otherwise industrial cold GRP surface. At the time of writing, this is what I am aiming for but before that I need to improve the background GRP somehow.

Having sanded all the interior wood and GRP I decided to paint the GRP surfaces but unlike the original builder I decided to try for a mat finish in the hope that the flattened paint would draw less attention than the high gloss used before.

I have read on the internet about paint used on the interior of boat cabins. Some writers declare that a standard home interior paint is all that is required. Others suggest that the climate in a boat cabin is more extreme and suggest that a kitchen or bathroom paint is more appropriate. Some have also reported good results using exterior masonry paint. I guess most of these writers were basing their choice on cost. Obviously home products are cheaper than those specifically designed for the marine environment. One thing they seem to have overlooked however, is that the actual amount of paint required is quite small. Paint for house walls tends to come in large containers. It may be cheap, but the cost is high if you have to purchase a much larger tin than you need – especially if you don’t have another use for it. I did the sums, a small tin of marine quality paint would be all I needed, and the cost was little more than a large tin of inferior house paint.

I chose International Paints ‘Toplac’ a one pot paint I have become familiar with. It is high gloss, but fortunately International also produce a ‘matting agent.’, add it to the paint and you have a flat mat finish – perfect!

So the white bits inside the cabin have been treated to degreasing, sanding, two coats of undercoat and a Matted Toplac finish.

If you are thinking about a similar treatment however, please note. Toplac without matting agent is high gloss, Toplac with 25% matting agent produces a ‘satin finish’, and Toplac mixed 50%/50% with matting agent gives you an ‘eggshell finish’. If you really want matt (as I did) you have to work with a mixture of 25% paint to 75% matting agent. Be aware therefore, that these matt topcoats contain very little pigment, you’ll need to build up several coats to get the depth of colour, and even then, the final result will be highly depended on the thickness of undercoat you were able to create beforehand.

So, the cabin now has four coats of paint on painted surfaces and five coats of Woodskin on the wooden areas. It has been a lot of work just to achieve a blank canvass, but worth it …………. I think.

Seaward