Why Is My Kilz Primer Bubbling?

DIY paint jobs can be very satisfying for a lot of us. But things do not always go as planned. For example, Kilz Primer is a top choice for DIYers and professional painters alike. But your Kilz primer might be bubbling like lava, and you don’t know why.

Kilz primers develop paint bubbles when you apply them to an unclean surface, leading to poor adhesion and loose paint. Always clean the surface you will be priming before you start the painting process. 

Kilz Primer products

This article will provide more details about precisely why Kilz primers develop paint bubbles and how to apply a layer of paint primer for a smooth finish.

What is Kilz Primer?

Kilz Primer is an adhesion primer that achieves a permanent bond by bonding the top layer of paint or finish to the surface being worked on. Adding primer to paint also helps prevent cracking and mildew.

You can use a gallon of Kilz primer on about 300 square feet of surface area. This primer is ideal for all types of surfaces cleaned of dust, grease, mold, rust, and old paint. 

Kilz primer can also be used as a color sealer to reduce staining on many surfaces. Make sure not to inhale fumes when using this or any other paint primer to avoid health issues.

Some of the benefits of using Kilz Primer include:

  •  Versatility: While some primers can only be applied to specific surfaces, Kilz can be used on wood, metal, concrete, and plastic.
  •  A mildew-resistant finish
  • Odor blocking

As you can see, Kilz Primer comes with plenty of benefits. It is a bit more expensive than other primers, but many DIYers find the cost to be acceptable, given the quality they get.

 However, despite this being a high-quality product, issues like sudden bubbling after applying coats of paint primer can arise.

Why Would Kilz Bubble?

paint bubbling and peeling problems on the wall

The main reason behind primers bubbling is lack of adhesion. If you see bubbles after applying Kilz, you might have applied it to the surface without cleaning it properly. When working with wood, make sure to clean it thoroughly with mineral spirits after sanding.

Other possible causes of Kilz Primer bubbling are:

  •  Moisture or high humidity can keep primer from adhering to a wall or other surface, creating bubbles in the process. This often happens in bathrooms and kitchens.
  •  Applying too much primer to the same area.
  •  Recoating and repainting without allowing enough time for it to dry.
  •  Tiny air pockets from stirring the product too fast. When you apply the primer, these air pockets will create bubbles.
  • Porous surfaces like oak wood often have small holes known as pores. Air pockets fill these pores and cause bubbles in the primer. To avoid this, it is best to seal porous surfaces before applying primer.

How to Get Rid of Bubbles in Kilz Primer

sanding surface of a drywall  to get rid of Kilz primer

Having bubbles appear after applying Kilz does not have to ruin your day. But it will take a bit of time to solve the matter. 

One of the most effective ways to deal with bubbling is to pop the bubbles and reapply the primer.

Follow these simple steps to do this:

  1.  Use a razor or needle to pop the bubbles in your Kilz primer. Make sure to do this with care to avoid injuring yourself and a possible trip to the hospital.
  1.  Use a paint scraper to get as much primer off as possible.
  1.  Use sandpaper to create a smooth surface.
  1.  Although you do not have to, applying a sanding sealer while performing surface prep is a good idea.
  1. Reapply a coat of primer and leave it long enough for it to dry properly before painting.

Related Post: PPG Gripper vs Kilz Primer: (Comparison Guide for DIYers)

Should I Mix Kilz Primer with Paint?

mixing primer with paint

It might seem like a good idea to mix primer with paint to save time from having to apply one at a time, but it isn’t. 

You should not mix your primer with paint because they are chemically different. The primer is meant to be a bond between the paint and the surface being painted. They must be applied to the surface separately.

If you’re really in a time crunch, it’s better to skip priming altogether instead of mixing the primer with another product. Instead, just use an unprimed paint coat.

Remember, though, that while applying both paint and primer separately does take more time, it ensures the best possible results.


Kilz Primer has many benefits that make it ideal for many painting projects. Whether painting a wall or another part of your house, this primer can help your new paint stick to the surface better and last longer.

If the product begins to bubble, pop the bubbles and start over. Be sure to clean off any dusty surface or otherwise dirty surface before applying the primer.