Primer and preparation: the basis of good paintwork

When people think of painting, they think of the final coat: the colour and the sheen you will see. Yet what lies underneath largely determines how long the result keeps looking good. A top coat on a greasy, dusty or bare surface will come away sooner, however good the paint is. In this article you will read what preparation involves, why primer is indispensable and how the approach differs from one surface to another, from bare timber to new plasterwork.

1. Why preparation pays off

Paint only adheres well to a surface that is clean, dry and lightly keyed. Dirt, grease and dust form a barrier, so the new paint ends up sitting on top like a skin. After a few seasons you see the result as flaking, especially where rain and sun hit hardest. For exterior work in the wet North Holland climate, that is the difference between paintwork that lasts for years and paintwork that soon needs attention again.

Preparation takes time, and it is exactly the part of the job you no longer see afterwards. Those hours do count towards the price, though. How a rate is built up and why cheap can turn out expensive is explained in what a painter charges per hour.

2. Cleaning, degreasing and sanding

The first step is always cleaning. Outside, the woodwork carries a film of dirt, exhaust fumes and sometimes algae; inside it is more likely to be grease from hands, cooking vapour or nicotine. A suitable degreaser and clean water remove it, after which the surface has to dry thoroughly.

Next comes sanding. An existing, well-adhering layer is sanded to a matt finish so the new paint has something to grip. Loose areas are removed first and their edges feathered, so that you will not see raised ridges through the new gloss later on. Finally, all sanding dust is removed with a vacuum cleaner and a slightly damp cloth. A forgotten speck of dust may seem harmless, but under a glossy top coat it becomes a visible bump.

3. Primer for each surface

Primer provides adhesion and protects the surface, and it forms the bridge to the top coat. Which primer is right depends on the material:

• Bare timber: a primer that soaks into the wood and seals it against moisture, especially on end grain.
• Metal: a rust-inhibiting primer, once rust has been brushed or sanded away.
• Plastic and smooth, previously glossed parts: an adhesion primer made for smooth surfaces.
• New plaster or plasterboard: a sealer or primer, but only once the plaster is completely dry.

Premium brands such as Sigma, Sikkens and Wijzonol have their own system of primer and top coat for each surface, designed to work together. Using primer and gloss from the same system prevents adhesion problems. Where the differences between the brands lie is covered in Sikkens or Sigma.

4. Filling, sealing and repairs

Between priming and the top coat comes the repair work. Holes, dents and joints are filled and, once hardened, sanded smooth. Joints between frame and wall or between glazing bead and glass are resealed where necessary with a paintable sealant. The filled areas are then primed again, otherwise you will see them later as dull patches in the gloss.

If there is wood rot in the frame, repair comes first: the affected timber is cut out, new wood or a two-component wood filler goes in, and only then is it primed. How to recognise early rot is explained in spotting wood rot in window frames. If the damage is so extensive that repair no longer makes sense, the considerations in painting or replacing window frames will help.

5. The right build-up of coats

A durable build-up usually consists of primer, possibly an undercoat, and one or two top coats. Each coat must dry sufficiently before the next one goes on, and the surface is lightly sanded between coats. On the exterior woodwork in Amsterdam-Noord, for example, the wood was given primer after the wood rot repair and then two coats of Sikkens exterior gloss.

If you live in the Zaan region, where many homes have wooden boards on the outside wall, fascias and bargeboards, that build-up matters even more: there is simply more wood that needs protecting. For the local approach, take a look at exterior painting in Zaandam. During the free consultation our painter will tell you what preparation your woodwork needs and then set out those steps clearly in the quote.

In practice this topic belongs with wood rot and window frame repair and exterior painting. There you can read about the approach and the options, or request a free, no-obligation quote straight away.

Further reading: Interior painting in Amsterdam, Interior painting in Zaandam, Interior painting in Haarlem.

Frequently asked questions