Chalk paint sticks well to porous surfaces, such as wood. But, can you use chalk paint on metal?
You can use chalk paint for metal surfaces, but you must sand and prime the metal. Since metal is non-porous, chalk paint doesn’t stick well to metal. But, sanding creates scratches on the metal surface that the chalk paint can “bite” into and stick.
Also, if the metal surface is painted or sealed, you must remove the previous finish before applying chalk paint. That’s because a sealer will prevent chalk paint from penetrating the metal surface.
Chalk Paint Sticks To Metal
Chalk paint will stick to a bare metal surface as long as the metal is in good condition and you sand it. However, if the metal surface is painted or stained, chalk paint won’t stick. You must remove the previous coating to allow chalk paint to stick to it.
Also, if there’s rust on the metal, chalk paint won’t stick well. Even if chalk paint sticks to rusted metal, the paint will peel off in a few weeks. So before applying chalk paint, you must remove the rust (and prevent it).
Chalk paint must penetrate a surface to stick. But, since metal is non-porous, it doesn’t allow the paint to penetrate its surface. So, you must sand the metal surface lightly to create tiny scratches (ridges) for the paint to soak into.
Compared to other paints, chalk paint has good adhesive qualities. That’s because of the thin and water-based nature of the chalk paint. Chalk paint sticks so well on surfaces that it can be used as a base coat (primer) for other paints or sealers.
Use a stain-blocking primer to increase the bonding between chalk paint and metal. The primer will serve as a base coat for chalk paint and allow it to stick better.
Related Read: Will Chalk Paint Adhere To Glass?
Chalk Paint Dry Time on Metal
It takes chalk paint 30 minutes to dry enough for a re-coat and 24 hours to dry fully (cure). Chalk paint has a fast dry time because of its water-based nature.
For chalk paint to dry its solvent (water) must evaporate from the coating. Since chalk paint uses water as its solvent, the dry time is water because water evaporates fast.
Also, since metal is non-porous, the evaporation process of the chalk paint solvent happens faster. That’s because all of the paint is over the top layer of the metal, and no paint is penetrated inside the metal. So, the air around the metal surface increases the evaporation of the exposed chalk paint.
However, the dry time of chalk paint depends on the room temperature, humidity levels, thickness and number of coats. During moist temperatures, chalk paint takes longer to dry.
How To Apply Chalk Paint On Metal?
Painting metal with chalk paint is easy; clean, sand, prime the metal, and then apply chalk paint.
Here are the tools you need:
- Chalk Paint
- 1 x Sealant (Polyurethane or Spar Varnish)
- A Mild Solvent (Like Rubbing Alcohol)
- Wire Brush
- 1 x Primer
- Foam Roller or paint sprayer.
1. Clean The Metal
First, clean the metal surface. Cleaning will remove dust, grease, and grime from the metal that can prevent chalk paint from sticking.
To clean metal:
- Mix detergent (or soap) with warm water.
- Damp a clean rag with the mixture.
- Use the dampened rag to clean the metal surface.
- For stubborn stains, use a degreaser.
- Wait 5 minutes.
- Clean the metal surface with water.
- Allow the metal to dry.
2. Remove The Existing Finish
If the metal surface is already painted, stained, or sealed, you must remove the existing finish before applying chalk paint. A sealer or paint will prevent chalk paint from penetrating and sticking to the metal surface.
Here’s how to remove the existing finish from the metal:
- Use mineral spirits for oil-based paints or rubbing alcohol for water-based paints.
- Apply the paint remover compound over the painted metal surface.
- Wait 15-20 minutes.
- Once 20 minutes have passed, the paint will start to bubble and change its form.
- Use a plastic paint scraper to scrape most of the paint.
- Re-apply the paint remover compound to leftover paint.
- Use a rag to remove the paint.
- Remove the paint removing residue from the metal (IMPORTANT!).
- Allow the metal to dry.
- Sand the metal surface with ultrafine-grit sandpaper.
You must use a plastic paint scraper as a metal paint scraper can damage the metal. Also, you must remove the paint remover residue from the metal as it can discolor or damage the metal surface.
After you remove the paint, sand the metal surface with ultrafine-grit sandpaper. Sanding will remove any leftover paint and create tiny scratches for the paint to soak into. But, you must only use ultrafine-grit sandpaper to sand metal before chalk paint. If you use coarse-grit sandpaper, you will damage the metal.
3. Prime The Metal
After the metal surface is clean and sanded, apply a stain-blocking paint primer. Paint primer has extra additives that allow the coating to stick to a metal surface. The primer will serve as a base coat and offer a smooth and even layer for the chalk paint to stick to.
To apply primer:
- Use a paintbrush, roller, or sprayer.
- You must use a stain-blocking primer as it prevents stain or moisture from affecting the chalk paint coating.
- Apply 2 coats of primer on the metal.
- Wait until the first coat dries before applying the next one.
Related Read: Does Chalk Paint Need Primer?
4. Apply Chalk Paint
Once the second coat of primer dries, apply the chalk paint over the metal.
Here’s a step-by-step guide:
- Use a paintbrush, roller, or sprayer.
- Apply 3 coats of chalk paint on metal.
- Wait until one coat dries before applying the next one.
- Optionally, sand between coats of chalk paint (except for the final one).
- Seal the chalk paint.
5. Seal The Chalk Paint
For outdoor metal surfaces, you must seal the chalk paint. That’s because chalk paint isn’t durable enough to withstand outdoor elements and will get washed off. Also, chalk paint isn’t water-resistant and won’t protect the metal from moisture or scratches.
To seal outdoor chalk-painted surfaces, use exterior polyurethane or spar varnish. When dry, a sealer will produce a glossy clear coat that protects the chalk paint and metal from moisture, water, and scratches. However, you must apply 2-3 coats of sealer for proper coverage and protection.
For indoor or decorative metal surfaces, sealing chalk paint is optional. That’s because indoor or decorative surfaces aren’t exposed to elements that can wash or damage the chalk paint coating.
Types of Metal You Can Use Chalk Paint Over:
Indoor Metal Surfaces
You can paint low-traffic indoor surfaces with chalk paint. That’s because indoor or decorative metal surfaces aren’t exposed to elements such as water, moisture, or handling that can damage the finish. Chalk paint will last 3-5 years on low-traffic indoor surfaces.
For instance, you can apply chalk paint on indoor metal cabinets. That’s because the metal cabinets aren’t exposed to water or moisture, so the chalk paint will last longer.
However, for high-traffic indoor surfaces, you shouldn’t use chalk paint. For instance, you shouldn’t use chalk paint on metal door handles because the chalk paint will get washed off from the constant touching.
Outdoor Metal Surfaces
You shouldn’t use chalk paint on outdoor metal surfaces. That’s because an outdoor surface is exposed to weather elements, such as rain, that can damage (wash off) the chalk paint finish.
Chalk paint isn’t a durable paint. The paint doesn’t have extra additives that make the finish durable or resistant to anything. If chalk paint is exposed to constant water, the finish will get removed.
Chalk paint doesn’t protect the metal surface from weather elements. A chalk paint coating will only change the color of the metal. So, if exposed to constant water, the chalk paint will get removed and expose the metal surface to weather elements. So, avoid using unsealed chalk paint on outdoor metal surfaces.
However, if you want to use chalk paint on outdoor surfaces, you must seal it with a sealant. A sealant such as exterior polyurethane or spar varnish will protect chalk paint from weather elements. When dry, polyurethane will form a glossy top coat over the chalk paint finish and protect it from water, moisture, scratches, and other damage.
You can use chalk paint on metal surfaces, but you must sand and prime the metal before applying chalk paint. Also, if the metal is already painted, you must remove the finish and then apply chalk paint.
For outdoor metal surfaces, sealing the chalk paint with a sealant is mandatory. Sealing will protect the chalk paint coating and metal surface from moisture, water, and other damage. For indoor decorative surfaces, sealing chalk paint is optional.