COVID-19 - Operating as normal but PLEASE order online and email us if you have a technical query if you can as we may not be able to answer the phone as quickly as normal - thank you.

Marine paint guide

A typical paint system will usually comprise of a primer and a topcoat onto a prepared bare substrate such as metal, GRP/gelcoat, wood or concrete. The primer serves as a thicker, protective layer and/or provides a good surface for a topcoat. The topcoat is usually a much thinner coating that provides an aesthetic finish and a final colour. With modern paints a mid-coat or undercoat is not always required especially if the primer can be mixed in a colour to complement the topcoat.

It is important to select the right primer for the substrate you are applying it to and you should be able to get a good idea if you read the category headings. As a general rule primers intended to protect metal from rust and GRP from osmosis are applied in a number of coats to form a thick water resistant layer – two-pack high build epoxies provide excellent protection. Surface preparation is important and the amount of time you are willing to take will affect the choices of primer you will be able to use and the success of the paint system as a whole. Surface tolerant primers can make preparation easier for metal substrates.

If you are applying a primer or topcoat over an existing paint coating you will be more limited in your choices as the new paint could react with the old. In this case, regardless, the success of the eventual coating will always come back to what you are painting over. Generally two pack primers and topcoats will not go on top of single pack coatings, however single pack primers and topcoats can go over prepared two pack coatings. If you are unsure of what you are painting over we can provide a FREE test kit. We supply single pack primers that provide a good ‘tie coat’ between existing coatings and seal old antifouling and undercoats that build the colour before applying the topcoat.

Because they are thicker than topcoats, if you intend to spray, the majority of our marine primers require airless spray equipment. An airless sprayer is different from a conventional paint sprayer as it pumps the paint through a nozzle rather than blow it out using compressed air.

Topcoats essentially provide a durable colour finish. They achieve this with pigments mixed in various quantities to produce 1000’s of colour variations and contain UV stabilisers to retain that colour. Unfortunately there is no International finish standard so the finish quoted be it gloss, semi-gloss, satin, low sheen or matt is a guide and can vary between products.

The topcoat requires the most attention to get the best results and we have tried to make it easier for brush and roller application with our LUSTRE range. If you have not used a specific topcoat before and are applying with a brush or roller we always recommend starting on a less visible area first so you get used to the paint. If there is a single tip for modern paints it would be to not overwork them – apply a solid layer and allow it to level, going over the same spot again and again reduces the chance of a smooth finish. If you are spraying most of our topcoats can use either conventional or airless spray equipment and the details for settings can be found in the ‘Guides’ section within the product details.

If you need help choosing paints you can send us a message, with as much detail of your project as possible, using the message system below or send us an email at info@smlpaints.co.uk.

P.S. Don’t forget the personal protection equipmet and accessories such as paint brushes, rollers, trays, and scuttles. All of our accessories have been tried and tested and are solvent resistant – not something you can guarantee with DIY store application products.