Primer & Undercoat Paint

Using a primer and undercoat before you paint can make all the difference to your finish. Primer and undercoat can help you prepare walls, wood, metal, and plaster, before painting for the very best results. You’ll find a wide range of primers and undercoats at Toolstation including brands such as Dulux Trade, Crown, Rustins, Leyland Trade, and more.

Primer vs Undercoat

Primer and undercoat do similar jobs, but they aren’t the same thing. Whereas a primer is used to prepare a wall the very first time it’s painted, an undercoat is applied to surfaces you want to repaint. Undercoat is described as a preparation product and is used to get a wall ready for a new coat of paint, often to prevent previous colours from bleeding through.

What Is Paint Primer?

Primer is a type of paint used to prepare a surface for its first coat of paint. This can include brickwork, plaster, wood, metal, MDF, and more. It primes the surface for painting and ultimately results in a superior finish. There are many different types of primer paint for both interior and exterior use, including quick dry, water-based and solvent-based, as well as spray-on acrylic primer. Primer and undercoat products are essential for professional quality painting. At Toolstation, you’ll find trade quality primers and undercoats at friendly and affordable prices.

 

Primers for Different Surfaces

Different surfaces require specific primer or undercoat products to ensure paint adheres properly and provides long-lasting coverage.

• Plaster and drywall – Primers seal porous surfaces and create an even base for emulsion paints.
• Wood and timber – Wood primers help prevent stains or resins from bleeding through topcoats.
• Metal surfaces – Metal primers improve paint adhesion and can help protect against rust and corrosion.
• MDF and engineered boards – Specialised primers seal the surface to prevent excessive paint absorption.
• Previously painted surfaces – Undercoats provide a consistent base before applying a fresh topcoat.

Why Use Primer or Undercoat Before Painting?

Applying a primer or undercoat helps create a smooth and durable base for decorative paint finishes.

- Improving paint adhesion on difficult or porous surfaces
- Sealing surfaces to reduce paint absorption
- Helping achieve better colour coverage with fewer topcoats
- Preventing stains, marks or previous colours from showing through
- Creating a more even surface for decorative finishes

Types of Primer and Undercoat Paint

Primer and undercoat paints are available in a range of formulations designed for different decorating projects.

- Water-based primers – Low odour and quick drying, suitable for many interior surfaces.
- Solvent-based primers – Often used for difficult surfaces where stronger adhesion is required.
- Stain-blocking primers – Designed to cover marks, nicotine stains or water damage.
- Multi-surface primers – Suitable for a variety of materials including wood, plaster and masonry.