What to Know Before Painting Over Zinsser 123 Primer

Although you can get away without priming in some cases, it’s always best to use a primer to make your paint coat more durable. Primers also improve paint adhesion and protect your surface from bleed-through, especially if you’re painting over wood with high tannin content.

Zinsser 123 primer is one of the most popular primer products and it’s available at most big box hardware stores. It is a water-based primer that’s compatible with both water-based and oil-based paints. Although applying it is straightforward, many have questions about painting over it. 

In this post, we’ll cover all you need to know about painting over Zinsser 123 Primer.

Can you paint over Zinsser primer?

Not only is painting over Zinsser primer okay, but it’s the next step that you should take no matter what. Primer is made to be painted over. 

Zinsser primer acts as a basecoat, which primarily works to:

  • Smoothen most porous and non-porous surfaces in preparation for the paint layer
  • Improve paint adhesion
  • Prevent minor bleed-through
  • Keep paint color hue and sheen
  • Improve paint durability 

Moreover, Zinsser primer is not meant to be a topcoat. So, it will not make your surface durable. As such, at least two top coats of paint is always best. However, you can learn more about priming without painting here

How long to let Zinsser 123 Primer dry before painting?

Since Zinsser 123 Primer is a water-based medium, it will typically become touch dry in less than an hour. According to manufacturer details, this is about 30-40 minutes.

However, it doesn’t always dry this quickly. Zinsser 123 Primer needs specific environmental conditions to dry fast. These conditions include:

  • Relative humidity at 10-85%
  • Temperature range at 10° – 32° C
  • Fair weather with no rain (if painting outside) 

If your working area has very high humidity or very low temperature, expect the dry time to be longer. This may range from an hour or even longer.

How many coats of primer are needed?

Based on the manufacturer’s details, you will only need one coat of Zinsser 123 Primer. Most other primers are exactly the same in this regard.

Although in most cases you will only need one coat, you may need two coats to properly seal extremely porous surfaces.

Additionally, if you are using primer to cover a stain or knots of wood high in tannins, you may want to cover these areas twice over. Two coats of primer will help to fully block in the stain or tannins from bleeding through. 

What paint can I use over Zinsser 123?

Zinsser 123 Primer works well with either water or oil-based paint. You can use almost any type of paint when you use this product including:

  • Latex paint
  • Acrylic paint
  • Enamel paint
  • Chalk paint
  • Mineral paint
  • Milk Paint
  • Clay Paint
  • Alkyd paint 

It’s a common myth that you can’t use water-based primer with oil-based paint. However, oil-based paint can stick to practically anything and it doesn’t require an oil-based primer per se. As a multi-purpose primer, it’s pretty hard to screw up with product. 

Should you sand Zinsser 123 Primer before painting?

Sanding Zinsser 123 Primer is not necessary.

However, if you are priming and painting a piece of furniture, sanding can eliminate brush marks that can dry like little ridges. Lightly sanding before applying the first paint coat ensures a completely smooth surface for painting.

Use fine-grit sandpaper to lightly scuff the primed surface. There is no need to apply a lot of pressure, and you’re certainly applying too much force if you are sanding through to the wood. 

In general though, sanding before painting isn’t necessary if you’re painting over glossy surfaces.

When to use other Zinsser primers?

Rust-Oleum’s Zinsser primers come in different varieties, so it can sometimes be confusing to pick which Zinsser primer to use for your paint job.

We’ve discussed the Zinsser 123 Primer in detail above. It is a water-based medium that adheres well to most surfaces. It provides some stain-blocking properties but it’s certainly not a specialty stain-blocking primer. For blocking water stains, tar stains, and tannins it is best to use either Zinsser Cover Stain or Zinsser BIN.

Zinsser BIN primer is a shellac-based medium widely used to prevent tannin bleed-through. Tannin is an acid chemical in wood that reacts with water, causing yellow stains or bleed-through. This primer adheres well to most surfaces except for floors, decks, and other surfaces with prolonged water contact.

This primer has comparatively higher VOCs compared to Zinsser 123 Primer. So, it is best to check label guidelines for use, safety precautions, and disposal instructions. It is best used for:

  • Spot priming persistent bleeds through on exterior walls and over water-based or oil-based primer
  • Sealing fire and water stains and odors caused by pets, fires, and smoking
  • Places with extremely cold temperatures (0°-90° F/-18°-32° C)

In contrast, Zinsser Cover Stain is an oil-based primer famed for its flexibility. It can be applied to most surfaces without causing swelling (unlike some other primers). It offers great coverage and is significantly cheaper than Zinsser BIN Primer.

This oil-based medium is also better than its water-based alternative at covering and preventing tannin bleed-through. However, it also has the most VOC content and the longest drying time. It takes at least an hour to touch dry and over a week to be cured.

It is recommended to use this primer for:

  • Glossy surfaces
  • Wood with high tannin content, like cedar, oak, and redwood
  • Covering water, fire, and smoke stains 

Additionally, Zinsser also creates various specialty primers such as mold-killing primer, primer for concrete and brick, and more. These primers are far too expensive to be used as multi-purpose primers. They should really only be used for their specific use case. 

Related: Do You Have to Paint over Zinsser Mold Killing Primer?

To summarize, use Zinsser 123 Primer on surfaces that are not prone to bleed through. It is also best for indoor use and it’s perfectly safe for homes with pets and children. After all, it has the lowest VOC content among the three other primers discussed. For severe bleed-through from tannin, water, smoke, or fire, opt for Zinsser BIN Primer. For durability both outdoors and indoors and some bleed-through, pick Zinsser Cover Stain.




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