The purpose of primer is to prepare the surface for the top coat of paint. It’s an important step in your paint project and will ensure a professional looking finish that will last. A primer often isn’t necessary but if you have any of the issues listed below, then one or two coats of primer are recommended for best results.

1. Bare drywall

The face paper on drywall is porous and so is drywall compound. Use specific drywall primer to seal the porous surface before the first coat of paint.

2. Sealing porous surfaces

Other porous surfaces requiring primer include bare wood and masonry. It’s recommended to use a specific primer engineered for that particular surface.

3. Cover stains

A coat of primer will ensure coverage of stains so you won’t see them through the top coat of paint. Tough stains, like smoke or water stains, will need a heavy duty stain blocking primer to conceal them.

4. Wood knots

Wood tannins are released from wood knots and can bleed through to the surface resulting in unsightly brown or yellow circular stains. Use a shellac-based stain blocker to prevent this.

5. Painting over dark colours

Using a primer over dark colours will make it easier for the lighter coloured paint to cover the dark colour. Primer is usually white but you can have it tinted the same colour as the paint to reduct the number of coats needed.

6. Glossy paint

Using a primer will help paint stick to glossy surfaces. It’s recommended to also scuff up the glossy sheen before you apply primer.

Types of primers

1. Water-based

Also called latex, these primers are the most common and are used for the majority of interior paint projects. There are latex primers specially formulated for covering tough stains, glossy paint and oil-based paint. All latex primers are easy to clean up with soap and water.

2. Self-priming paint

Latex paint-and-primer-in-one is essentially a paint that is thicker than regular paint. Use this if your walls are in good condition. If you have any issues with your walls, it’s preferable to use a separate primer. Because this paint is thicker, it takes longer to dry. Clean up with soap and water.

3. Oil-based

Very effective in blocking stains from showing through the top coat of paint. Can be used on variety of surfaces including galvanized metal and bare wood. Note that they are slow-drying and can release VOCs. Clean up with paint thinner.

4. Shellac

This primer is for coverage of serious stains, smoke damage, smells and to seal wood knots. They contain VOCs so the area will need to be well ventilated. Follow manufacturer clean up instructions, usually with ammonia or denatured alcohol.

Using the right primer at the right time can make all the difference in achieving a smooth, durable finish that lasts. Whether you’re dealing with porous surfaces, stains, or dark colours, primer helps ensure your top coat adheres properly and looks its best. If you’re unsure which primer to use or need expert advice, don’t hesitate to visit your local TIMBER MART — our specialists are here to help you choose the perfect products for your project.