Can you use Chalk Paint Straight Over Varnish

One of the greatest benefits of chalk paint is it requires minimal prep before application. Chalk paint adheres well to practically all wood surfaces.

But what about varnish, specifically? Can you use chalk paint straight over varnish? This post addresses this very question.

KEY TAKEAWAYS

Although chalk paint has incredible sticking power, it’s best to prep varnished furniture by lightly sanding it before applying chalk paint. Chalk paint has a hard time adhering to glossy varnished surfaces since there is no texture for the paint to “grip”.

Related: Can You Use Wax Finish Over Stain?

Why you should prep before using chalk paint on varnished surfaces

Chalk paint adheres well to most surfaces. However, when it comes to varnished surfaces, a bit of chalk paint prep is almost always necessary. 

Varnish is generally a super glossy type of top coat. It can bring furniture to life, but varnish doesn’t create a texture that allows paint to stick to it easily.

Varnish essentially acts as a slick barrier between the raw wood and the paint. Chalk paint has no problem adhering to bare wood, but if there is a layer of shiny varnish in the way, you will probably end up just sliding your chalk paint around the surface. The paint simply won’t be able to adhere well to the surface and it will be easy to simply scratch the chalk paint off with a fingernail.

Chalk paint has a particularly hard time adhering to oil-based varnish. After all, chalk paint is water-based paint and varnish is oil-based. Since water and oil don’t mix, the chalk paint will essentially sit on the varnish rather than sticking to it.

If you’re working with a water-based varnish with an extremely low sheen, the chalk paint will have an easier time adhering to it. However, for the most durable results, it’s important to carry out the proper prep. 

How to prepare high-gloss varnished surfaces for chalk paint

Step 1: Sand off the finish

First, make sure that you are either working outside or in an area of your house with good ventilation. It can help to open a window. If you choose to work inside, be sure to wear a facemask so that you don’t inhale any wood dust.

Use a piece of fine-grit sandpaper for this project (around 220 grit). Lightly rub your wood furniture back and forth with your sandpaper. For greater efficiency, use a palm sander if you have one. 

You can tell if the finish has been sanded off by holding a light to the furniture. If you can no longer see the shininess to the finish that used to exist, you have successfully removed the varnish. Only a few strokes with the sandpaper should be needed.

Once you have finished sanding, be sure to wipe down your furniture with a damp cloth to remove the wood dust.

Step 2: Apply your primer (if needed)

In most cases, chalk paint doesn’t need primer. Without a layer of glossy varnish, chalk paint will have no problem sticking to your wood.

Nevertheless, under some circumstances, it’s important to prime your wood furniture before painting. 

If the wood is high in tannins, you should apply stain-blocking primer. Tannins are essentially a tree’s sap that can be visible in raw wood. When tannins bleed through paint, they create a yellowish-brown stain that can ruin a paint project. 

The following types of wood are high in tannins:

  • Oak
  • Cherry
  • Walnut
  • Mahogany

Stain-blocking primer essentially blocks the tannins from bleeding through the paint. Shellac-based primers are particularly effective. 

Step 3: Apply your chalk paint

Now that you have properly prepped your furniture, you can proceed to apply your chalk paint of choice!

Apply chalk paint with a roller or brush to cover your furniture. Always apply two coats for the most durable finish. 

Final words

If you want to use chalk paint straight over varnish without any prep at all, be sure that you clean the furniture at the very least first. There are a few materials to clean your furniture before painting, but you should use TSP for the most thorough cleaning. 

Sanding and priming might not always be needed, but a good cleaning to remove dust and grime is almost always necessary for the best quality paint job. 

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