Be very careful and consider the results you will get if you use a paint and primer in one step. I have seen a lot of ads pushing this idea of one-coat painting, but that just plays to people’s idea that painting is a drag and one coat would be quick and easy. It is not messy and it is not hard to clean up.
It’s actually easier and safer to go with the old method of a first coat of primer because if you get the wrong type of primer (there are many) in your paint and primer in one, you will be starting all over when you think you are done! For primers: jump to the bottom to see the list of the best products and what they are for.
Why use a primer
Generally, primers are for sealing and giving porous surfaces a first ‘drink’ so they are paint-able ( and so the next coat will adhere). On the other hand, paints are for looks and, outdoors, for looks and protection.
Below I explain why it’s better to do the primer alone in the first step instead of using a paint and primer in one (plus you will always have some left over and it comes in handy). But sometimes a paint and primer in one step can be a big help.
When can you use a paint and primer in one?
In which situation can you use a paint and primer in one? When your walls are without stains and when you have no new wood. Wood almost always has some kind of resin that will bleed through many primers. Even if your wood is not going to bleed through, the hard/soft grains will accept the first treatment differently and swell at different rates causing a nice smooth sanded wood to become rough.
If you are painting walls and want to try a paint with a primer in it, be sure that your walls are:
- without stains (such as water stains, mold stains etc)
- have no unprimed wood
The best paint and primer in one
Buy a quality paint and primer in one: use Kilz, a very good name in primer, and for sure one of the best paint and primer in one. I would trust this product, it is also a primer with low VOCs.
WARNING: If you are not using a high-quality paint and primer, you will really have high VOCs. Read my post on VOCs.
What is inside your Paint and Primer in One?
There are several types of primers. Some paint primers are designed to seal out stains, and some to create a bonding surface. What kind of primer did your paint and primer in one come with? I would not know either. Is it rust? Metal? Plastic? Cigarette smell? Bold colors need primer-love too.
A very good reason to not use a paint with primer: Your health. Why using toxic ingredients if you do not need them? Paint and primer in one have much more VOCs compare to a quality paint and many primers.
Primer for wood: do not use a paint with primer in one
My friend asked me why his wood ceiling would not cover after 4 coats of paint. Should have called me first dude. Resins in wood and stains in walls that pick up impurities need a shellac based primer to stop the stains from bleeding through (that is an alcohol-based goo).
Do you want to “prime” your new walls? That’s a horse of a different color: a shellac or other sealer is not necssary. A stain-killing primer will do it, but why buy more firepower than you need? Why breathe that stuff if you don’t have to?
Surfaces with different absorption rates
Drywall and the “mud” compound that covers seams and spots where the screws are will soak up paint differently. As a result, if you don’t use a primer to stop the absorption (paint won’t do it), you will always see the seams and spots.
Get the right paint products
You have to know what you are doing before you go shopping. Ask me or ask a real paint store (not a big box store: they hire monkeys). If you have a paint and primer in one tinted to your color and now you are reading this and thinking that you may have made a mistake: yes, I’m sorry you did, and that tinted paint cannot be returned. use it anyway, but be aware, you will probably need a coat more than you planned (and you only needed those ‘primer’ chemicals in your first coat).
If you get it wrong, you will not seal tannins, stains, resins, or oils that you should have sealed and it will have to be done again. Don’t shoot the messenger. These impurities bleed through latex paint: latex does not have any real sealing properties. Good to buy a small sized can and test one area before buying all the paint.
Use one coat of primer
Honestly, in most cases, with the right tools and the right clean-up tools, one more coat is not that big of a deal for an average room. Now, if you are doing a warehouse-sized room, yes, maybe it is going to be worth it, but please call the paint store representative, perhaps even the district rep if you are risking that much investment. Paint store managers study the chemistry of paint and are trustworthy sources. You can always write to me also or leave a comment below.
The whole ball game is what are the solids in the solution of your paint, in your primer, and in your paint and primer in one? It is the solids that wind up doing the job for you.
When NOT to Use Primer (and When You Must):
Stains: at least spot prime where they appear. (Sometimes when we know we need more than one coat, we will start with a coat of regular finish paint, wait and see what bleeds through, then spot prime those, then apply final coat–this way we get them all and don’t waste time with non-stains).
Drywall: yes, always, but only with drywall primer which is not nearly as intense as stain killers. Be sure to dust those new walls first or you will have a gritty wall! (We use a push-broom). We have a longer article about drywall primer and the key steps involved.drywall primer and the key steps involved.
New wood: if pine, you will need an oil primer. Other woods you may get by with water-based. Therefore, ask your paint store manager: they know. I have written about other paint issues here.
List of Primers
Here is a list of the different kind of primers: go here to choose your weapons when you know what you need. The second one is my main go-to choice: the original alcohol based primer. So, have some rubbing alcohol on hand to clean your hands. Use a cheap brush and throw it away for most of these (even the water-based ones as they get gunky after a bit). Don’t expect these brushes will work for cutting lines. Read my post on that. This is the end of my post. Good luck!
- KILZ Original Multi-Surface Stain Blocking Interior Oil-Based Primer/Sealer (Low VOC Formula): blocks most stains including water, smoke, tannin, ink, pencil, felt marker and grease.
- The original BIN: alcohol-based and works everywhere. More than you need probably.
- Main drywall primer: Rust-Oleum Corporation 01501 Drywall Primer: Won’t raise the nap on new drywall…sands easily.
- Kilz General Purpose: Not recommended for flooring, glossy surfaces, mold- and mildew-prone surfaces, or for stain blocking.
- KILZ Adhesion High-Bonding Interior Latex: Bonds to tough-to-paint surfaces including Kynar, PVC, Formica, vinyl, glass, tile, glazed brick, chalky paints, glossy finishes, fiberglass, and metals.
- KILZ Premium High-Hide Stain Blocking: Excellent adhesion for most surfaces, use on interior and exterior drywall, plaster, woodwork, paneling, masonry, and brick. Ideal for high-humidity areas including bathrooms and laundry rooms…to seal light to medium stain
- KILZ MAX Maximum Stain and Odor Blocking: For tough stains from water damage, rust, smoke, nicotine, grease, tannin, ink, pencil, felt marker, pet stains and more while also sealing pet and smoke odors…water-based.
- KILZ Klear Multi-Surface Stain Blocking Interior/Exterior. Water based. Formulated to bond and seal porous and chalky interior and exterior surfaces with a tough, flexible, and breathable clear coating. for sealing drywall, plaster, wood, galvanized, aluminum, architectural plastics, masonry, and brick. Soap and water cleanup and dries fast – ready to recoat in 1 hour.
This is the short, common list. One painter in Indiana has a great page on primers and of course the internet authority, Wikipedia is on the ball. Sherwin-Williams has a great article on types of problems.