What primer do I need? Types of primers and their uses explained

How to prep a surface for priming

Although priming is part of the preparation process for painting a surface, there is some prep that needs to be done before even the primer can be applied.

Step 1: Thoroughly clean the surface

Before you prime you need to ensure that the surface is completely free from dirt, dust, grime, mould, or anything else which will affect the end result. 

If you are just priming interior surfaces you will be able to use sugar soap and water to clean any dirt, grease or even nicotine staining. Simply either make a sugar soap dilution or use a premade spray and wipe the area with a clean damp cloth. Once you are confident the dirt has been removed, you can go over the area with a clean cloth to get rid of any remaining traces of the sugar soap.

For surfaces which have been affected by mould, you will need to use a bleach solution or a fungicidal wash to thoroughly clean affected areas. Painting over these areas without treatment first will only lead to the problem seeping through eventually.

For external surfaces, you will probably need something a little hardier than a cloth to tackle the grime. Use a pressure washer to blast the dirt from the surface, working a stiff-bristled scrubbing brush to loosen dirt as you go. 

Avoid using bleach outside to tackle mould as it can be harmful to wildlife. Instead, you can try spraying undiluted white vinegar on affected areas and leave for one hour - this should kill the mould spores allowing you to continue pressure washing and scrubbing the surface. Be sure to cover your plants for this stage as vinegar is a natural weed killer. You can also use a fungicidal wash on exterior surfaces or a sterilisation wash.

Step 2: Repair and sand

Once you are happy with the cleanliness of the surface you can move on to any repairs that need to be made.

Small nicks and chips in interior walls can be repaired with general purpose or fine surface filler by filling the damage, scraping off the excess and smoothing flat when dry.

It is a similar process for wood repairs too, using a wood filler to fill the damage to the wooden surface. Simply scrape off the excess and sand to smooth it out.

Next, you will need to sand the surface with fine 220 grit paper. If you are priming a large surface area you may want to opt for a palm sander, otherwise it will be a tiring task. Once you have treated the whole area wipe clean with a damp towel and allow to dry before priming. 

Step 3: Protect your surroundings

Before you start applying the primer, it is a good idea to protect your surroundings by removing all furniture and ensuring the room is well ventilated. 

Cover any remaining pieces, carpets or flooring with a drop cloth or dust sheet to protect against splatter and use painter’s tape to mask off mouldings, fixtures, trims and the ceiling.

Once you have completed these steps you can start applying the primer. Check out our guide on how to apply primer for some quick tips.

Types of primers for every surface

When it comes to primers there is no one-size-fits-all option and getting the right type of primer for your surfaces is vital for that professional-looking finish and desired longevity.