Yacht paints and coatings

1.Surface Preparation for yacht paints on Bare GRP

All fibreglass substrates should be thoroughly degreased and cleaned, to remove traces of mould release agents that may be present with a suitable surface cleaner. The surface should then be lightly sanded with medium to fine abrasive paper to provide a keying pattern for the subsequent yacht coatings, the substrate should then be thoroughly wiped to remove any dust.

Previously coated surfaces - Topsides

If the existing marine coatings are in good condition and adhesion is still good, proceed with thoroughly degreasing and cleaning the existing coating followed by sanding with medium to fine abrasive paper (180-240). Thoroughly remove all dust and sanding residuals before starting the paint application. Apply undercoat and topcoat as required.

If the existing yacht paints and coatings are in poor condition, cracking or flaking paint, then it is necessary to remove the old paint with either a remover or by scraping or sanding. And then proceed with the preparation as described for bare substrates.

Previously coated surfaces - Below the waterline

If the existing coating is in good condition, it is generally enough to remove any powdering or loose  parts of the old antifouling, by sanding with a fine abrasive paper and applying 2 coats of the new antifouling compatible with the existing one. if the type of antifouling is unknown it is recommended to apply 2-3 coats of solver primer intermediate undercoat before applying the new antifouling.

If the existing hull coating is in poor condition, cracking flaking and loss of adhesion from substrate it is necessary to remove the old antifouling with a suitable antifouling remover or by sanding with medium abrasive paper, thoroughly remove all dust from the substrate. Then proceed with preparation as described for bare substrates.

2.Surface preparation for boat paints on Bare Steel

The surface preparation of steel before applying an anticorrosive coating system is very important and could directly affect the life/adhesion of your marine coating system.

The steel surface should be free from rust, corrosion and traces of oils, the best method of surface preparation is to carry out adequate shot blasting in accordance to SA2.5 standard if this is not possible it will be necessary to prepare the surface by using grinders, wire brushing and sanders to remove any traces of rust from the substrate, before the application of a coating system. If the substrate has been shot blasted, the application of EPOZINC (zinc-rich, cold galvanising primers) is recommended, giving a high quality anticorrosive barrier. The recommended coating system for below and above the water line in either one or two component should then be applied.

Previously coated surfaces - Topsides and below the water line

If the existing paint is in good condition and there is no rust, cracking or bubbles within current paint-work, then it is recommended to thoroughly clean, degrease and sand the surface with a medium-fine abrasive paper removing any dust and  sanding residue from the surface. After the preparation has been carried out it will be suitable to apply your preferred coating, undercoat and topcoat system or protective coating and antifouling system.

If the existing coating is in poor condition, if there is rust showing, flaking, cracking, loss of adhesion from the substrate it is recommended to remove the old coating by mechanically sanding, shot blasting or with a remover and proceed to prepare substrate as described for bare substrate.

3.Surface preparation for boat paints on wood Bare substrate

The wood should be thoroughly cleaned and degreased to be free from traces of oil and grease, which may be present especially with oily woods. Sand the wood with a medium-fine abrasive paper in order to provide a rough pattern that allows a keying for the subsequent coating system. All dust and sanding residuals should be thoroughly removed from the substrate by brush and vacuum cleaner. Clean the surfaces with a cloth soaked with Thinner 203, allowing to dry fully before applying the recommended coating system.

If the paint is in good condition, with no cracking, blisters, flaking or  loss of adhesion then it will be possible to clean and degrease the existing coating and sand with a medium-fine abrasive paper taking care to remove all dust and sanding residue from the surface before starting the paint application. After this has taken place proceed with the application of suitable undercoat and topcoat.

If the paint is in poor condition, flaking loss of adhesion, cracking, then the coating should be removed back to the bare wood either by a remover or by sanding and scraping, taking care to remove all the dust and sanding residue from the surface. It is important then to follow the recommended coating system for bare wood. Like with any substrate it is important to make sure that the surface preparation is carried out and suitable primers applied to gain a long lasting finish.

Previously painted substrates - Below the waterline

If the paint is in good condition and a new application of yacht antifouling is required, it is suitable to sand the existing coating with a medium abrasive paper ensuring that there is no marine growth and flaking or loss of adhesion. After removing all sanding residue from the substrate, apply 2 coats of antifouling. If old antifouling  is unknown it is recommended to apply 2-3 coats of Solver primer before the application of the new boat antifouling.

If the old paint is in poor condition, loss of adhesion, cracking then it is important to remove the old coating from the substrate by using a remover or by sanding and scraping back to the bare wood removing all sanding residue from the surface. It is important to use the recommended coating systems for all types of boat construction especially wood, taking acre to use suitable primers below the waterline, achieve a barrier before the application of antifouling. Antifouling is only a protection from marine growth/fouling.

Boat Varnishes

There is nothing more eye catching then perfectly varnished wood, enhancing the natural colour and the beauty of the wood, but also adding protection from the severe marine environments. The surface preparation of wood before varnishing is important not only to achieve a long lasting finish but the clear nature of varnish will show any area of the wood which is in poor condition or which has not been prepared properly.

Surface preparation for yacht varnishes on Bare wood

The wood should be thoroughly cleaned and degreased to be free from traces of oil and grease which may be present especially in oily woods. Sand the wood with a medium-fine abrasive paper in order to provide a rough pattern that allows a keying for the subsequent coatings system. All dust and sanding residues should be thoroughly removed from the substrate by brushing and vacuuming. Clean the surface with a cloth soaked with Thinner 203, allowing to dry fully before applying the recommended varnishing system. When priming wood with varnish depending on  the Skipper's Line varnish which is used, dilution of the varnish with the appropriate thinner will aid the penetration of the varnish enabling better adhesion to the substrate.

Previously varnished surfaces

They may be different reasons as to why you need to re-varnish.

A. The varnish is crazing, showing loss of adhesion, UV damage to the wood resulting in loss of colour

or

B. Simply good maintenance on your behalf by wanting to apply a fresh coat of varnish.

if the reason is B, it will be suitable to sand the existing varnish with a fine abrasive paper and thoroughly clean and degrease the surface, removing all dust and sanding residue.  Proceed with the application of a varnish compatible with the pre-existing one, if the varnish is unknown then it is recommended to remove the varnish back to bare wood or to do a test patch to see if the varnish is compatible.

If  the reason is A, varnish is crazing, cracking, coming off or has lost its colour, then it is recommended to remove the old varnish back to bare wood, by using a remover or by sanding and scraping the varnish, making sure that the surface has been thoroughly cleaned and degreased. Proceed by following the surface preparation for bare wood and follow up with recommended varnishing system.