Milk paint is one of the oldest forms of paint. It’s been found in cave drawings from 8,000 years ago and even in the tomb of King Tut. It was first used as decoration, and then as a protective coating. The original formula for milk paint contained common ingredients like lime, casein (a protein found in milk), water and earth pigments.
Milk paint hasn’t changed much over time, but it has been “enhanced”. General Finishes milk paint is an interior/exterior water-based paint that’s extremely durable. Milk paint mimics the look of old-world furniture paint and is very durable. I like using milk paint because it’s easy to work with, and is essentially fool-proof. I prefer to use General Finishes milk paint over other brands because it’s already mixed, unlike some that come in powder form. I’ve used their milk paint on 3 different projects over the last year.
Fun fact: Farmers used cows blood mixed with milk paint to paint their barns which is why most barns are red.
Preparation: Clean & Sand
The first steps are the most critical, because without proper prep work your project could fail. Prep work is different depending on the existing state wood. Does it have an existing finish, or is it bare wood?
General Finishes recommends that you use a scotch brite pad to scuff clean and use a 50:50 mix of denatured alcohol and water with the pad. You can use any type of all purpose cleaner, or a de-greaser to clean the piece, but I do not recommend using anything with phosphates such as TSP because it could leave a white haze behind.
After thoroughly cleaning, you’ll want to begin sanding.
- Bare Wood: Use 120 and go up to 150. Do not use any grit that is finer than 150 because you’ll wind up sealing the wood grain.
- Existing Finishes: Sand with a fine-grade like 220 and work your way up to 320 or 400.
Should You Use a Primer?
- Knots in Wood: Knots can be difficult to work with because paint doesn’t like to adhere to the sap in the knot. It’s a good idea to use a darker paint color over knots. If you really want to use a lighter paint color, you can use a stain blocker but that won’t guarantee that the knots still won’t bleed through.
- Existing Finish that has a Dark Paint Color: If you’re going to paint a light color over a dark color, you’ll want to use a stain blocking primer to prevent the color from bleeding through.
- Metal: While General Finishes milk paint is designed for wood surfaces, it may stick to metal surfaces like steel or aluminum if you use a metal primer first.
- Laminate: Milk paint may stick to laminate if you use a “bonding primer”.
- Fiberglass: You can apply milk paint directly to fiberglass without using a primer.
- Plywood: You can apply General Finishes milk paint directly to plywood, but using a primer will prevent the wood from bleeding through the paint.
Application of General Finishes Milk Paint
- Stir the paint to blend in any solid material that has settled at the bottom. You’ll want to continue to stir throughout the application process.
- You can use a foam brush, paint pad, synthetic bristle brush, microfiber roller or a paint sprayer to apply the milk paint.
- You can apply as many coats as you’d like, but 2-3 coats tends to be the standard. The paint needs to be fully dry before applying an additional coat. It should be fully dry within 2 hours, depending on the temperature and humidity.
- General Finishes recommends that you allow the paint to cure for at least 21 days before placing objects on the surface.