Paint primer has a multitude of attributes. They are not only stain blockers but they are also a base coat that provides adhesion on a problem or hard to stick to surfaces. With so many options available it can get a little confusing choosing the right primer for the right job. Should you use an oil-based primer over a pigmented shellac-based primer? Or should you use a Latex-based primer? What is the difference?
Don’t worry, we will give you the ultimate primer guide and answer all of your questions here.
When To Use Paint Primer On Walls?
Whenever you have bare drywall it is absolutely a must that you prime and seals your walls.
Sealing the walls will prevent moisture from getting into your walls.
In addition, it will ensure that your topcoat doesn’t’ peel off once it dries.
This also applies to areas that have been patched.
You always want to prime patched areas after repair.
Additionally, this will seal the joint compound and allow for an even topcoat finish.
What Paint Primer To Use On Bare Drywall?
Whenever you are sealing new drywall and/or patches, you want to use a PVA primer.
The price for PVA primers ranges from $10-$20 US per gallon.
If you are trying to use a lower-cost product then Glidden PVA paint primer is what you would want to consider.
You can pick it up at Home Depot and it is great for sealing drywall and joint compound.
It is very transparent and sometimes hard to point out when dried.
A 5-gallon bucket goes for $40-$50 and is great for larger and commercial projects. Also, it will help you keep your costs low.
It is a water-based product and cleans up easily with just soap and water.
Another option is Kilz-PVA paint primer. It ranges from $50-$60 (5-Gallon Bucket)
We prefer to use this primer at 518 Painters because you get the most bang for your buck.
Because it seals porous surfaces and is dry within 15- 25 minutes which is great for productivity.
Just like the Glidden it is a water-based product and cleans easily with soap and water.
Our go-to primer for bare drywall is Benjamin Moore’s FreshStart.
It is a bit more pricey than other primers but it is a Hi-build primer that covers and blocks stains like no other.
Whenever we have to paint dirty walls and ceilings due to soot or other messes FreshStart outperforms. In addition, it saves us a boatload of time.
What Are The Downsides To PVA Primers?
PVA primers are very transparent and have the consistency of milk almost. Therefore they are not good for blocking stains and can be a little messy coming off your roller.
Does Primer Have To Be Perfect?
Primer doesn’t have to be applied perfectly.
You should however cover all bare surfaces that are being painted.
If not, you risk the chance of losing adhesion. This can cause your topcoat to peel off eventually.
You should also be aware of any drips.
Your base coat sets the foundation for a smooth surface.
Therefore it is suggested you sand your walls with 150-220 grit sandpaper after priming.
How Many Coats Of Primer Should I Use?
Unless you have a surface with stains that are bleeding through severely, in most cases, one coat is enough.
What Primer Should I Use On Wood?
You will have to use a different primer depending on what type of wood and what condition the wood is in.
For bare wood, you can use a high-quality latex primer or an oil-based primer.
Read more about Best Oil Based Primers For Wood And More
That is if your wood isn’t seriously stained.
If you have wood that is stained you will need to use a stain-blocking primer.
The same goes for painting redwood or cedar.
If you see that the latex primer is not effective you will have to switch to an oil-based primer.
The Downside is that Oil-based primers have a strong odor and are not as easy to clean up as water-based primers.
Do I Have To Prime Painted Wood?
Generally, you will not have to prime previously painted wood.
In some cases, you will have to de-gloss them by either using a liquid sander such as M1 Liquid Sander or by scuffing up the surface with 220 grit sandpaper.
A brillo pad will work too. Just be sure to clean your surface with a damp rag before priming to ensure an evenly smooth finish.
If the wood has been painted with an oil-based product you will definitely have to scuff and prime it because the hard and slick surface of the oil paint will not allow for proper adhesion.
If however, the painted surface has some chipping spots you will have to scrape and remove all loose pieces and then spot prime them with a high-quality latex primer or an oil-based primer.
Read more about How To Paint Over Gloss Paint
Can I Prime Weathered Wood?
Absolutely, you will have to sand your weathered wood until you see new wood fibers, then proceed to prime using a high-quality latex primer or an oil-based primer
Can I Prime Galvanized Metals?
If your surface has rust on it you will have to clean those areas with a grinder or wire brush to remove all loose pieces. Then you can proceed to prime your metal surface using a corrosion blocking primer. Insl-X Stix bonding primer is great for these types of surfaces.
It is a waterborne urethane acrylic bonding primer that has the ability to bond to various surfaces.
This includes tile, PVC, Glass, and even vinyl.
What Is The Best Primer To Block Stains?
When you are dealing with any stains that have oil or wax in them there is really only one option of primer you can use which are Oil-based primers.
If you try to use a waterborne product you will see that the marks will keep bleeding through the surface.
This includes any crayon, pen, permanent marker, or felt pen marks.
Read more about Best Oil Based Primers For Wood And More
How To Stop Tannin Bleed?
You will see tannin bleed through a lot on cedar and redwood or whenever you are painting old kitchen cabinets.
We learned that the best way to stop this bleeding is to use a pigmented shellac-based product. It blocks bleeding better than oil-based primers. It is also sandable, dries within 30 minutes, and is a relatively low price.
The downside is the strong odor and it is difficult to clean.
It is very thin-bodied, therefore, it has the tendency to splatter if you move too quickly.
How To Block Water And Nicotine Stains On Walls And Ceilings?
We found that after cleaning your surfaces with dish liquid and water the best way to block water and smoke damages is using an oil-based primer.
Zinsser B-I-N is our personal favorite. The downside is that drying times are a little prolonged with an oil-based product.
You could use a shellac-based primer if time is a concern but it can get messy, especially when you are priming ceilings.
How To Clean Oil Based And Shellac Primers?
Personally, I am not a fan and wouldn’t recommend using any solvents such as paint thinner.
What works for us at 518 Painters is denatured alcohol. Occasionally we will use Ammonia.
I suggest you wear proper protection when you use oil-based or shellac-based primers.
Always wear gloves and long sleeves if you can to avoid skin contact.
If you do get any primer on your skin you can use denatured alcohol or coconut oil.
In Conclusion
If you have a large area that needs to be primed such as a commercial building, go with a less expensive primer such as Glidden PVA
If your surfaces are dirty and you need to hide stains go with Benjamin Moore’s FreshStart
If you have to prime bare wood and want to stop tannin bleed, use an oil-based primer such as Zinsser Coverstain.
If you have smoke or water stains and you need a fast-drying product that will block the stains and odor, go with a shellac-based primer such as Zinsser Bin but keep in mind that when you use oil-based or shellac-based primers you want to use natural bristle brush!