Surface treatments

• Paints are used to protect timber when you want to cover up the grain and it changes colour
• Undercoat is the first coat of paint. It covers up any previous colours more cheaply than applying extra layers of the final 'topcoat'. Its function includes providing a tough barrier to prevent water penetration and evening out rough surfaces
• Gloss paints are hard-wearing and water-proof and come in lots of colours. They're shiny and used for things like interior woodwork. You apply them with a brush or roller, painting in the direction of the grain.
• Polyurethane paints are even tougher than gloss paints. They're used for things like children's toys. They're often sprayed on for a smoother finish.
• Varnish can be coloured or clear, and either gloss, matt or satin.
• Yacht varnish seals the wood and makes it waterproof. Its quite flexible, so it doesn't crack if the wood moves. Its good for things like doors and window frames.
• Polyurethane varnish is best for interior uses. E.g. stairs and skirting boards. Its very hard-wearing.
• Woods that will be used outdoors are often treated with a wood preservative.