How to prepare a surface for painting

Here at Blastrite we specialise in supplying the equipment you need to sandblast your surfaces ready for paints and coatings to be applied. However, sandblasting your surfaces isn’t always practical i.e. on the interior walls of a house, so we’ve put together a list of tips to help you manually prepare a variety of interior surfaces ready for painting...

Stripping old paint

If the previous layer or layers of paint are starting to flake then you will need to strip them away before repainting the surface, otherwise your new layer of paint will begin to flake shortly. There are several potential methods that you could use to remove old paint:

• Scraping: It is time consuming, messy, and can damage the surface in some cases.
• Heat gun: It is efficient but not suitable for some surfaces such as wood which may get scorched.
• Chemical strippers: They are efficient and less toxic than other methods. Simply paint the liquid on, wait for it to work, then scrape it off easily.

Preparing walls and ceilings

When it comes to painting walls, there’s quite a bit of preparation required. The smallest hairline crack in the plaster can really show up under a new paint job, so it’s important to prepare the surface properly as follows:

• Use a primer: If the wall is newly plastered then you’ll need to use a primer to seal the plaster before applying any paint to it.
• Wash the wall: If the wall already has paint on it, wash it down and rinse it before removing the paint. Make sure the wall is dry before painting.
• Remove wallpaper: Use a steamer to remove any old wallpaper from the wall before painting.
• Remove mould: If there’s any mould on the wall, remove it using a fungicidal cleaning product, then apply a primer to the wall before painting.
• Remove stains: Fat or grease stains need to be removed before painting as they prevent the new paint from adhering to the surface.

Preparing wooden surfaces

All naked wood must be treated with a primer before painting, even if it is old wood which has previously been painted and stripped. Use sandpaper to give the wood a smooth surface, then wipe it down with a damp cloth to remove the sawdust. Try to ensure that you work with the grain in order to maintain the natural appeal of the wood and help the paint to stick better.

Preparing metal surfaces

One of the biggest problems facing metal surfaces is rust. If your surface has been affected, start by removing as much of the rust as you can with a wire wool brush, before treating the surface with a couple of coats of primer that has been specially formulated for rust. If your metal surface is non ferrous it should be washed with white spirit, cleaned, and given a good coat of primer before painting.