Updated July 2024 by Stephen Cochrane. There’s a really short answer to this question and it is ‘YES’. Paint primers, or sealer coats prepare the surface for a superior result for your interior repaint. If you want that “Instagram” finish to your painting work, you need a primer or a sealer. Which, why and how? Let’s talk about professional house painting vs DIY and how you can create a near pro-looking job this renovation!
What does a primer or sealer actually do?
Primers and sealesr have special bonding agents that help them stick to the surface of walls – new or old. So it sticks well to walls … and then paint sticks well to the primer or sealer. This means it provides a sturdy ‘interface’ between the wall … and the final, quality coats of paint. Primers or sealers also allow the top coat to go on more smoothly providing a better quality, longer-lasting finish.
Primers Vs Sealers Vs Undercoats
Primer:
- Blocks stains, tannins and other imperfections leaching into your final paint finish
- Creates a “paintable” surface on raw building materials
- Smooths imperfect surfaces
- Most also prevent mold, fungus and bubbling by creating a moisture barrier
- Stops rust when painting metal surfaces
- Helps paint stick to “tricky” surfaces like tile, laminate or existing gloss paint.
- Helps paint stick to doors, skirting boards and other “glossy” surfaces
- Prevents peeling and chipping and helps your new paint “last longer”
- Primers help “hide” previous paint jobs. So, if you’re trying to cover up that HORRIFIC colour scheme your teen, or tenant chose, you’ll need a primer.
- Primers can reduce the number of top coats needed, and are cheaper than finishing coat paints. If the wall has flaws to cover, a primer will save you money, not cost you money.
Sealer:
- Sealers are a specific type of primer designed to stop the top coat from leaching or soaking into the substrate.
- Sealers are essential for highly porous surfaces like concrete
- Sealers are essential if you are painting a damaged wall, crumbly wall or aged gypsum plaster
- If you’re using a sealer AND a primer, you should apply the sealer first.
Undercoat:
- Undercoats come after the primer and/or sealer
- The main purpose of undercoats is to ensure a completely uniform colour prior to adding top coats/finishing coats.
- Undercoats used without primers or sealers may not be enough to hide imperfections and bright colours
- You will need an undercoat for most painting tasks regardless of whether a sealer or primer is used. Some paint products offer am “all in one” prepcoat that combines undercoats with sealers or primers. If you’re choosing to use an “all in one” – choose wisely. We always use and recommend Dulux paints. And NEVER use or recommend “no name” discount store paints. You will have SERIOUS regrets. We love Dulux but if you’re not using Dulux, use a reputable brand.
But, really, do I need a primer coat? What could happen?
Do I need a primer coat? Well, you don’t. You don’t need to do anything you don’t want to do. Nobody is the boss of you. When could you “get away without a primer?
- If you are painting over an existing wall that was previously sealed/primed, and painted in a similar colour to the one you are re-painting with. So, a repaint or renovation where you’re not changing much and you’ve previously done a superior job painting the area. Also, it wasn’t too long ago – so the wall is still in excellent condition.
- When you’ve got money to burn so you’re excited to pay more for finishing coats.
- When you LOVE repainting and want to do this again soon.
- If you’re renovating to sell a house and you’d like lowball offers.
- If you don’t mind when your paint job flakes off easily and looks rubbish 😉
The obligatory reminder, we’re Perth’s most experienced, most-awarded painters
A J Cochrane have been Perth painters for four generations. We’re approaching a CENTURY as Perth’s most reputable painting company. So you know, we’ve got a bit of experience in these matters. While we understand you’re on a tight budget and are eager to do a little DIY painting, know that if it all goes to pot, you can call us in to finish the job. Painting your home on a budget means doing it right, or blowing the budget when you need to “undo newbie mistakes”. Before you rush to the hardware store, do some research and learn how to renovate your home successfully.
