Types of Primers
It is vital to examine the type of surface you are applying the primer to prior to commencing work. There are several different types of primers including latex based, oil based and shellac based to name a few, selecting the wrong type will have dire consequences to your project. If you are unsure, your local paint store will be able to advise you accordingly.
When to Prime
Any unpainted surface needs to have primer applied to it prior to paint being introduced. Omitting this step can cause issues later if the paint fails to adhere properly including peeling from the surface.
A previously painted surface may not require priming but if you choose to do so then you should ensure to remove all loose paint and sand the surface lightly before applying the correct type of primer.
Latex based primers provide a more flexible finish that is resistant to cracking.
Suitable uses :
- Galvanized metal
- Bare softwoods such as pine
- Masonry such as brick or concrete block.
- Unfinished drywall
Oil Based Primers
Suitable Uses :
- Previously varnished wood.
- Cedar, Redwood or other woods prone to tannin bleed.
- Unfinished wood.
- Over existing paint that is failing.
- Heavily weathered wood.
Suitable uses :
- Wood, metal, plaster.
- Knots and stubborn tannin bleeding.
- Water, smoke, and rust stains.
Priming over Oil or Latex Paint – How to Know
If you’re unsure of the type of paint you are priming over, denatured alcohol, paint de-glosser, or non-acetone fingernail polish remover will help you to determine between the two. Wipe the painted surface with a dab of either of these substances, oil-based paints won’t be affected. If it’s latex based paint, some of the paint may lift or the painted surface may manifest a tacky feel to it.