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Introduction GRP Basics Essential Tools
Colour Pigments
(This page)
BACK TO FULL LIST OF PROJECTS
Introduction GRP Basics Essential Tools
Colour Pigments
(This page)
This page looks at the various ways of obtaining gelcoat with the correct pigment to match your boat's colour. The term gelcoat as used here includes normal gelcoat & the flowcoat variety.
When undertaking repairs on a GRP boat, pigmented (coloured) gelcoat which matches the the existing colour is used. There are several ways of obtaining this.
The easiest & most convenient way to get matching gelcoat for your boat is to obtain a Gelcoat Repair Kit which essentially consists of a small quantity of flowcoat to which the correct pigment has already been added. For this option you need to know the names of the colour pigments used on your boat. This may be printed in the instruction manual/documentation which came with the boat, otherwise it can be obtained by contacting the boat builder. Stewart Brown at Churchouse Boats can mix up and supply small quantities of suitably coloured Gelcoat Repair Kits for most (if not all) colours ever used on Luggers (or other Drascombe boats). Whilst this is quite adequate for minor repairs, it is prohibitively expensive for larger quantities of pigmented gelcoat necessary for extensive restoration projects.
If your boat has a GRP hull or deck, with a white gelcoat finish then white Plastic Padding Gelcoat Filler is an excellent Gelcoat Repair Kit. This product comes pre-coloured with white pigment and is widely available at most chandlers in the UK. Note that when catalysed it is slightly more paste-like in texture than standard flowcoat and is more amenable to application with a plastic spatula than with a paint brush
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Plastic Padding Gelcoat Filler - Ideal for repairing damage on areas of white gelcoat |
Gelcoat Repair Kits are fine for small or 'one off' repairs but for larger restoration projects it is cheaper to purchase colourless gelcoat and the pigments separately. Because white is widely used on GRP boats (especially hulls), it is possible to purchase large quantities of pre-coloured white gelcoat. Otherwise, for other colours, the pigment is added to the colourless gelcoat as required.
To obtain pigments matching your GRP boat colours it is important to know the trade names of the colours used. For recently manufactured boats, most of the pigments used in the Drascombe and Devon boats are made by West & Senior If you do not know the name of the pigments used on your boat you can try and match them with the Drascombe & Honnor Marine Devon colour swatches reproduced below.
| Some GRP Colour Pigments used on Currently Manufactured Drascombe & Devon Boats | ||
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| Colour (approximate) | Pigment name | Manufacturer & Name of Retailer |
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Cream |
All these gelcoat pigments are manufactured by West & Senior as part of their FASCOL range. West & Senior do not sell directly to the public but their products can be ordered online from East Coast Fibreglass Supplies NOTE that due to display differences of colours on different computer monitors, the colour swatches reproduced in this table are only for guidance and are not an exact representation of the final result. Printed colour charts for West & Senior pigments can be requested from the contact information on their web site. |
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Light Admiralty Grey |
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Manilla |
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Motorway Blue |
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Oxford Blue |
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Racing Green |
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White |
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For older boats it is likely that the pigments are no longer made or will only be available in small quantities as Gelcoat Repair Kits. The only other alternative (particularly for large scale restoration), is to purchase some pigments & blende them until they match the original colour scheme of your boat. Pigment recipes for the Drascombe colours Aquamarine and Duck-Egg Blue are reproduced below.
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The first step is to find an area of gelcoat on the boat that is not faded and which can be used as a comparison when mixing the pigments. One way to do this is to remove a fitting such as the jib cleat fitted to the deck. The underlying gelcoat (as shown in the photograph, left) has been protected from sunlight and reveals the original colour (and the extent of the fading of the adjacent gelcoat!). If this is not possible, a sanding block with 1200 grade wet-or-dry (waterproof abrasive paper) can be used with water to rub away a small test area of faded gelcoat and expose the original gelcoat colour beneath. This is a good method to use on the hull GRP. |
The next step is to obtain a pigment colour card (similar to that from a decorator or paint store) from your chosen pigment supplier. The printed card will be a much more accurate representation of the colours than on a web site equivalent. It's then easy to choose the colours which are closest to those used on your boat.
Llewellyn Ryland are another UK manufacturer of gelcoat pigments and their Colour cards can be viewed online. The GRP supplier Blue Gee include some printed copies of Llewellyn Ryland colour cards as part of a comprehensive free printed catalogue of GRP/Epoxy materials.
Let's take the colours of Sospiri as an example. For the Aquamarine hull gelcoat colour the West & Senior Turquoise pigment seemed the closest match but needed some additional green tinting which I decided that their Traffic Green pigment would add. In addition I purchased some White pigment which, if required, would make the blended pigments paler. Each of the three pigments were purchased in 500 gram tins.
For smaller quantities an alternative source would have been the Blue Gee Blue & Green Colormatch kits as supplied online by Sailboats UK. Each kit consists of three 20 gram tins containing different shades of the same colour. A 20 gram tin of their Super White pigment would complete the required pigment range.
Likewise for the Duck-Egg Blue where, curiously, the nearest match seemed to be West & Senior Light Admiralty Grey with just a touch of Traffic Blue pigment the whole made paler with white pigment.
Again the alternative for smaller quantities would have been the Blue Colormatch kit supplied by Blue Gee consisting of three 20 gram tins containing different shades of blue, plus a 20 gram tin of their Super White to make the colour paler if required.
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Materials Required
This photograph shows the tools & materials required for Aquamarine pigment mixing. Three tins of pigment paste (green, blue & white), three small 10 ml disposable plastic syringes (for accurately dispensing measured quantities of pigment), a miniature jam-jar (with screw lid) for mixing the pigments (also useful as a dispenser), plastic spatula for mixing, pen & notebook for recording the quantities of pigments mixed, a roll of paper towel and disposable latex gloves (mixing pigments is messy!) (Click on image for larger view) |
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An Ideal Pigment Mixing/Storage/Dispenser jar
This small glass jar once contained 28 grams of jam! This is an ideally sized container both for pigment mixing, storage & dispensing. The screw top lid keeps the contents secure whilst the wide neck makes it very easy to dip a small spatula in to dispense tiny amounts of pigment to stir into gelcoat. The squat shape also means that the jar is not easily knocked over. These miniature jam-jars can be obtained from supermarkets selling boxed pots of various jams. They also turn up on the breakfast table of some hotels. Some potted 'meat pastes' are also sold in jars of this size. |
The following pictures summarise stages in blending green, blue and white pigments to match a patch of polished aquamarine gelcoat on Sospiri's hull. In reality there will be many more stages of experimentation than shown here. Also note that some pigment pastes are very viscous and they may be difficult to suck up using a syringe. If this is the case they can be thinned slightly by stirring in a few drops of Styrene.
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Mixing the Pigments to match the Aquamarine of the
Hull
Syringes are used (see photo above), to add pigments to the small jam jar (quantities accurately recorded in the notebook), where they are thoroughly mixed using a plastic spatula. Next, add a smear of the pigment mix to a drop of colourless flowcoat (the resulting colour will be slightly lighter in tone than the mixed pigment alone). Smear a small amount of this pigmented flowcoat on a polished (unfaded) area of the hull. Any colour variation between the mix and the hull will be evident. If the match is not acceptable, change the colour by adding small amounts of additional pigment to the jar. As you vary the amounts of pigment, try to think in terms of the basic colours, i.e.; the colour needs to be bluer or greener... This will help you identify which of the pigments to use. Add very small amounts of the pigments using the syringes to record the amount of each pigment added. The resulting 'recipe' will make it very easy to mix the correct amounts of pigment in the future. Leave each of the smears of pigmented flowcoat on the surface until you have the colour as close to the gelcoat colour as you can get it. When you are satisfied with the colour match, wipe away all of the test smears with acetone. The final mix in the jar will be sufficient for many repairs, but if required, having kept an exact note of the quantities used, it will be very easy to use the 'recipe' to mix up more pigments in exactly the right proportions to match your boat's colour. If stored in a a sealed container the pigments have a virtually indefinite shelf life and, when the boat is sold, can be passed on to the new owner ... |
Having successfully mixed matching pigments for Sospiri, the 'recipes' are reproduced below. These hopefully will be useful to those owning boats with the same colours. NOTE that all the base pigments are from West & Senior and, apart from the 'Traffic Green' pigment, all are from their 'FASCOL' range.
For the Aquamarine colour, the closest pigment seemed to be Turquoise, but as this contains a high element of blue, I reasoned that a bright green (Traffic Green) was needed to counteract this. White was used to lighten the result to give a very close match.
The Duck-Egg Blue pigment has a very high component of grey so I chose Light Admiralty Grey as the main pigment. As regards the blue I found that the Turquoise used as an ingredient for the Aquamarine pigment could not be used as an ingredient for the Duck-Egg blue, as it has a green component which gives completely the wrong shade of blue when mixed with the white and grey pigments. The answer was a dark blue pigment (Traffic Blue). Only a very small amount of this blue, mixed with the grey and White pigments, resulted in a very close match.
| 'Recipe' for Drascombe Aquamarine | |||
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Turquoise (11 ml) |
+ Traffic Green (5 ml) |
+ White (4 ml) |
= Drascombe Aquamarine (20 ml) |
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.jpg "Traffic Green")
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| 'Recipe' for Drascombe Duck-Egg blue | |||
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Light Admiralty Grey (23 ml) |
+ Traffic Blue (0.5 ml) |
+ White (12 ml) |
= Drascombe Duck-Egg Blue (35.5 ml) |
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Having mixed the pigments to match the colours of the gelcoat on the hull and deck of Sospiri, I was all set to start the GRP & gelcoat renovation.