Deck Painting

Our choice for treating the decks once the teak decking had been removed was to paint them.

The coach house on Maringret had been painted approximately 10 years earlier. Once we had removed our teak decks we decided it was best to paint both the decks and coach house which would kill 2 birds with one stone and also let us avoid issues such as how to have edges between 2 paint colours that were similar but not identical. As we had more work to do in the cockpit we planned not to paint above the blue line around the cockpit coaming, that would be done in a subsequent season.

When we bought Maringret the previous owners gave us the International Paint colour codes for the paint they had used. We thought we were in a good position, although there might be a minimum order we were confident that we could get more matching paint with a minimum of hassle. Well that was the thought anyway. We contacted International who informed us that they had “retired” the colours we wanted. We assumed that meant that we would have to pay some surcharge in order to get them to mix a minimum order of the paint. But no, that’s not how it works. International really couldn’t be bothered, we spoke to them at a boat show, they said the proper method to contact them was via email or phone calls. Of course once we were at home and trying to contact them they didn’t return phone calls or emails. The one time we caught someone answering the phone they suggested we “pick another colour”. What great advice. So we sort of gave up on International, we realise that our boat may be more important to us than it is to them but nevertheless their customer service really sucked.

So we were out looking for a paint supplier again, the 2 other players in the field were Jotun and Blakes (part of Hempel Paints). Maringret had always had Jotun anti-fouling when we bought her. After 2 seasons of trying to get Jotun anti-fouling in the UK we gave up, the dealer network in the UK just doesn’t seem to be set up for pleasure boats. Our inquiries regarding purchasing paint gave the same results which was quite unfortunate as Jotun Paints have a great reputation, friends in the Netherlands used them and thought they were unbeatable.

We talked to Blakes Paints (now part of the Hempel Paints company), they were quite willing to try and get as close to our existing paint as possible. We decided to go with Blakes and they were fantastic. Numerous phone calls to Martin at Technical Support were always answered promptly and knowledgeably. We couldn’t have asked for more in a paint company. They took us through the RAL colour code system and using this we found the best match for our existing off-white colour. We then had a digital photo of our Ducth friend Henk’s deck. Blakes had a very close match to that in 1-part paint which they very kindly agreed to mix up as a 2-part paint for us. There was a minimum order quantity of 5 litres but this seemed to be quite reasonable and we easily would use up 5 litres of paint on a 41 foot boat. We decided to use 2-part paint for our project as it is a more industrial product than the 1-part paint

We decided to have a off-white base (RAL colour code 9010) with sand coloured (Blakes colour code 20410) areas where we would mix in the anti-slip material. We did not want a single colour that covered the decks, contained the anti-slip and also covered the coachouse. We wanted to avoid colours that were too dark as they tend to hold heat – often becoming too hot to walk on. We also wanted to avoid too light a colour as that can cause terrible reflection problems when looking into the sun. As is our usual practice we took pictures of boats with nice deck colours for the couple of years prior to choosing a colour for ourselves.

RAL Colour Codes
Off-white for decks and coach house 9010
Sand coloured for anti-slip areas on deck 20410
Blue for boot-stripe and coaming stripe 5010

One thing we learned in our colour matching search is that the same colour will appear to be different depending on what material it is applied to, also whether a paint is mixed as flat or gloss finish will alter the appearance of the colour. We initially used the colour samples on websites but eventually moved to colour cards when we had narrowed it down to under 5 samples. Finally Blakes sent us out a “brush sample” which is a piece of cardstock with the actual paint applied to it. Once we had the different sample types in hand we could see how they did not appear to be identical. We could also place them on the unpainted decks and see how they would look.

Below are diagrams of the stages of deck painting:

1 – sealed with Blake’s EPU 2 – coated with white paint (RAL 9010) 3 – undercoated with sand paint (RAL 20410)
4 – RAL 20410 paint mixed with sand 5 – overcoat of sand paint (RAL 20410)

The diagram above only shows the function of the paint layers, it does not indicate how many layers of each functional layer were applied. In fact our plan is to keep applying additional coats of 20410 over the encapsulated sand as the previous paint is worn down.


The deck areas were already prepared by the removal of the teak decks and the subsequent making good of the gelcoat surface, what had not been done was to prepare the coach house for painting. The first step was to remove all the windows and clean the dirt, grit and salt that had formed between the window frame and the fibreglass. Then other removable fittings had to be taken off, including the hand rails. The coach house of the HR 41 is mainly covered by a textured gelcoat, something we called “elephant hide”. It seems that a textured material was placed inside the mold when the coach house was laid up. The textured effect is partly anti-slip but also a decorative feature. Outlining these patches of textured gelcoat are smooth margins, also the sides of the coach house are smooth.

Keying For Paint Application

We needed to make sure that all areas to be painted were both clean and keyed so the paint would adhere to the coach house. Keying is the process of giving the paint a mechanical grip on the under surface. Often this is done with fine sand papers or other gentle abrasives – for an interesting explanation of how modern paint works see Wikipedia’s Paint article. For ensuring the cleanliness of the surface we depended on our favourite acetone applied with paper rags. The margin areas and the smooth sides of the coach house were keyed with 320 grit paper. We didn’t worry about removing all the old paint if it was still adhering, what we did was key it all to ensure a good grip for the new paint. On the textured areas (i.e. the elephant hide) we scrubbed them with 3m Scotch-Brite scouring pads with Vim (AKA CIF or JIF) which is a gentle abrasive cleaner. We then rinsed the coach house extensively in order to make sure there was no trace of the detergent in Vim left behind. The coach house was then left to dry until there was no trace of moisture.

A 2-Layer Approach

We decided that for a consistent finish and to minimise the amount of masking we would apply our 9010 colour starting from one toe rail, across the deck, up and over the coach house,  across the deck on the other side to the opposite toe rail. This would avoid any joins and we could do all this without masking – except for the blue stripe around the cockpit coaming and the deck fittings that had not been removed (e.g. the mast foot and chain plates). After that was complete we would then mask for the 20410 anti slip areas.

we decided to paint the decks and up to the blue line around the cockpit coaming (but not above it)

Painting is much like epoxy work in that “cleanliness is king”. We used disposable “moon suits” which cover everything except feet, hands and face. Latex gloves and footwear then seal the body in other than the face. This is necessary to avoid any contaminants such as body oils from fingerprints, hair or other particles being on surfaces. If any contaminants do get on the surface being painted then the bonding will be partial and the results may be disappointing.

We put on 5 coats of 9010 on the decks by roller – the last 2 coats covering both the decks and the coachhouse. In the end the decks had 5 coats before the 20410 was applied and the coachhouse had 2 coats with the 2 final coats of 9010 being applied from one toe rail up and over the coachhouse and across to the other toe rail. Being a 2-part paint the Blakes is sensitive to the ambient temperature and warmer temperatures will cause it to “go off” or start curing faster. Maringret was inside a metal shed so we had removed any concerns about wind or rain  but as the shed was constructed out of sheet steel and was not insulated we still had the effect of the sun to deal with. We measured that with Maringret sitting in a cradle the deck level would be about 3 meters above the concrete floor. This 3 meters would increase the temperature by up to 10 degrees. There were certain days (luckily not when we were painting) when the temperature on deck was 35 degrees and power tools were stopping due to their thermal cutouts. To avoid these temperatures we started painting at 5 AM – basically you have to determine when it will be too hot to paint and subtract enough hours from that time so that a coat can be applied. Applying one coat took about 4 hours and then we would let the paint dry until the next day. Both of us were cleaning the surface prior to starting the paint and then one person would mix and supply the paint while the other person was solely responsible for the application. Any small tasks such as wiping up drips, mixing the next batch of paint etc. were handled by the non-painting person. Management of the “wet line” and coverage were the prime responsibilities of the painting person. Having a manpower plan such as this seems essential to success. Different plans can be used but the boats we saw who did not have a rough plan at the start were the ones who would have to sand off a failed coat of paint.

Prior to applying the next coat, the previous paint must be cleaned. Unless you are able to paint in a proper paint room where the air is filtered there will be airborne contaminants which settle on the paint in the 24 hours while it is drying between coats. We additionally had an infestation of spiders above our painting area. Prior to applying each coat we had to knock them off the roof with a long pole. In preparing for applying the next coat it is important to use a cleaning product that does not disturb the previously applied coat which will not be fully cured. Blakes Paints advised us not to use acetone for cleaning between coats as it would partially dissolve the previous coat. Instead they recommended methylated spirits. When performing this cleaning remember that the purpose is to remove any airborne contaminants that have settled in the previous 24 hours, the purpose is not to attack the relatively new paint as if it were spring cleaning time. Gently wipe off the paint surface using paper products wetted with a cleaning product approved by the paint manufacturer (in our case methylated spirits).

We did not paint above the blue line on the cockpit coaming, this meant that we were painting “around” the boat and could not avoid a “dry line”. When painting making sure that wet paint never meets paint that is already partially dried is referred to as maintaining a “wet line”. A perfect finish requires maintaining the “wet line”. Some tricks to “loose” the “dry line” is to never have it in the same place from coat to coat, also place it in a corner if possible, place it where it is the smallest length, place it around a curve or corner which will take attention away from it. Then afterwards you can cut polish the ridge that will remain from the “dry line” meeting. We could have avoided any “dry line” problems if we had had 2 people painting, they could have worked in opposite directions around the decks and meet on the opposite side, thereby preserving the “wet line”. Having 2 persons painting would have implied a 3rd person to supply and support them and we were not able to find anyone interested in doing something like that starting at 5 AM.

Once we had our desired number of coats on we left the 9010 for a few days to cure further. Our next step was to mask off all the areas that would receive the 20410 colour paint with the anti-slip mixed in. This paint was going to be much more fiddly to do with many corners, curves, margins etc. We would have to walk over the previously applied 9010 to apply the 20410 and wanted to make sure there was no risk of our footsteps disturbing the 9010 undercoat.

Masking Off For the Anti-Slip

Accurate masking off is critical to the end result, especially when there will be a visible edge of the sand coloured anti-slip area painted over the white undercoat. For this we used our favourite Scotch 2214 masking tape. For the corner radiuses we used pin-striping tape from our local car painting supply. We set the desired radius in the pin striping tape (we used a 6 mm wide tape) and then overlapped it with the 2214 masking tape to provide a wider area of cover when the roller was putting down paint. Pin stripe tape will roughly handle a radius twice its width when masking curves.

1st masking tape marks the final edge of painted area 2nd masking tape overlaps 1 to 2 mm into area to be painted

To end up with a smoother edge to the paint, on the straight or gentle curving edges we used 2 layers of 2214 masking tape as follows:

pin striping tape masks curved edges masking tape overlaps the pin stripe tape
and also masks straight edges

The first (i.e. bottom) layer of masking tape marks where the paint edge will eventually fall. Then put a second layer of masking tape over the first but advance the edge next to the area to be painted so that it overlaps by between 1 and 2 mm. Now apply roughly half the desired number of coats and then remove the upper masking tape. Then precede to apply the remaining coats of paint. The subsequent coats of paint will then “ramp up” from the first layers onto the subsequently applied layers. This technique gives a much more gradual edge to the paint where multiple coats are required and the paint edge is visible against a different coloured background (i.e. the paint edge is not in a 90 degree angle).

Applying Initial Layer(s) For Anti-Slip

The underlying RAL 9010 off-white was cured for a number of days meaning we could walk on it carefully. We wiped it down with methylated spirits using paper towels. We painted 1 coat of the 20410 which would act as a coloured underlay for the anti-slip. If any particles of anti-slip came loose then instead of a point of RAL 9010 white showing through there would be RAL 20410 sand colour showing through which would not even be noticeable.

This picture was taken after all the coats of white (RAL 9010) had been applied – they were applied from one toerail, across the side deck, over the coach house roof, across the opposite side on deck to the toe rail on the other side.Once this had had a few days to harden we masked up for the anti-slip (RAL 20410). In this picture the first coats of the 20410 have been applied, just forward of the aft chainplate there is a margin across the anti-slip area – it is hard to detect as it is mainly filled with masking tape which is not very much different from the RAL #20410 in these lighting conditions.What is yet to come are the coats of RAL 20410 mixed with sand. Once we achieved what we thought was a sufficient thickness of anti-slip grit, we than put on some more coats of RAL 20410 to seal the grains of sand in place.Also the foredeck has no 20410 applied as the anchor windlass base has not yet been fitted.

Applying Layers With Anti-Slip

We made various experiments with different commercial anti-slip products and also kiln dried sand used in the construction industry. We felt that the commercial products were both expensive and too fine to be effective as anti-slip. We then tried the kiln dried sand, it gave a good grip against slipping and the amount added to the paint would directly control how aggressive the anti-slip action was. We sifted the sand about 5 times through a kitchen sieve to remove large pieces of grit which would not fit in with the rest of the sand. We mixed the sand in with paint in various proportions, it always seemed to sink to the bottom so that when the roller went into the tray it would pick up paint with only a trace of sand in it. We experimented with various methods of applying the sand to freshly applied paint (i.e. before the paint had gone tacky). We tried various shakers, sieves and other implements (many from the kitchenwares section of the local food store). In the end we settled on using a salt shaker. All salt shakers are not created equally so make sure that the shaker you select has holes in its lid to match the flow rate of sand you want. We then applied the sand in a “side to side” motion, some evidence of the shaking motion is visible but once everything is dried that seems to be a finishing effect as much as anything else. Next we applied a coat of paint to attach sand to areas we had missed or that had not received enough sand. This was repeated as many times as necessary.

Applying Final Layer(s)

To help bind the sand to the deck we then applied 2 coats of 20410 over the top. This was to help lock in the grains of sand, it also has the side effect of making the decks slightly less aggressive as the sharp corners of the grains of sand are covered by the paint. As part of ongoing maintenance we plan to keep applying additional coats of 20410 over the encapsulated sand as the previous paint is worn down. Covering an area but with the irregular grains of sand on the deck increased the amount of paint required by 50%.

Cut Polishing

We will be waiting until after the winter to cut polish. By that time the paint will be well cured.

  • the best method for applying paint is to spray it, due to availability of facilities we were not able to spray Maringret
  • the second best method (some argue it is the best) is to apply the paint with a roller and then have a second person follow with a high quality paint brush which is used to “tip off” the applied paint, to have followed this approach would have necessitated us finding us a 3rd person
  • the third best method is to roll on the paint, this will leave the paint with an “orange peel” quality which is the pattern left in the paint by the roller as the roller pulls away from the paint it has just deposited. Assuming the paint has enough layers this finish can then be “cut polished” out once the paint has cured
  • as the decks will be thinner after the removal of the teak, temporarily refit all deck fittings before painting – we didn’t do this and had to modify fittings to handle the thinner deck with fresh paint in place
  • deck fittings that are mounted with bolts will probably adapt to the thinner deck while fittings like fuel fill points often are designed a for a specific deck thickness and will need adaption
  • if we had had more time we would have done light sanding between coats to reduce the orange peel effect

  • After one year the paint is stable and resilient. The sand used as anti-slip has been great while working on the boat and wearing shoes.

  • technical support at Blakes Paints (UK) – thanks Martin and Darren!
  • Henk on Vintage Freedom in the Netherlands who had already done this and showed us the way!

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