Is watering down paint the same as thinning paint?

For those unfamiliar with exterior painting and exterior paint, “watering down paint” and “thinning paint” probably sound somewhat synonymous. They’re actually not. In this article, we’ll explore the difference and go through how you can be sure your contractor isn’t watering down your home’s exterior paint.

Watering down paint

All paint contains water. In fact, acrylic latex paint is about 40% water. This is what makes paint a liquid that can be applied to a surface. Too little water, and the paint would be thicker and less pliable. You’d be unable to get it onto your brush, much less apply it to the outside of a home. It’s helpful to think of the water in paint as the delivery mechanism that carries the pigment in paint to the surface being painted.

Painting the exterior of a stucco home requires a lot of paint, and high-quality paint can be expensive. It’s one of the largest overhead costs in an exterior painting project. In an effort to cut costs and increase their own profits, some less-than-honest exterior painters try to make their current paint supplies stretch further by watering down paint. To do this, they add significantly more water to the paint, increasing the volume they have on hand.

As you might expect, this leads to subpar results. When you water down exterior paint, it changes the color by making it lighter. This means that the end result often differs from the sample patches or the digital renderings, if the contractor provided them at all.

Watered-down paint also causes inconsistencies, especially when the water and paint are poorly mixed. Finally, watered-down paint is less UV-resistant, adheres poorly, is more prone to chalking, and—just generally speaking—isn’t going to last as long as the manufacturer intended.

Thinning paint

In contrast to watering down paint, “thinning” paint is a regular practice for all painters and is recommended by the paint manufacturer. To “thin” paint, an exterior painter will add water to the paint bucket, increasing the paint’s workability and slowing down the speed with which it dries.

This is especially helpful in hot climates, including summers in the Sun Belt. In temperatures above 85 degrees, an exterior painter will need to thin paint to slow down the drying process.

So, what’s the difference? It really comes down to scale. When a painting contractor waters down paint, they are typically adding a significant amount of water to it. Think two gallons of water for every five gallons of paint. In contrast, the process of thinning paint involves a relatively small amount of water: 2-4 cups for every five gallons of paint. This small amount of water improves the workability of the paint without diluting it or leading to negative results.

When an experienced and trusted painting contractor thins paint, they’re doing so within the manufacturer’s specifications. If they add too much water to the paint as part of this process, it’s commonly known as “over-thinning.”

The difference between the “over-thinning” paint and “watering down” paint is one of intent: “over-thinning” typically is a correctable mistake made by an otherwise well-intentioned contractor, while the act of “watering down paint” implies that the contractor is intentionally trying to stretch their paint—and the truth.

How to know if paint is being watered down

Start by asking your contractor about their paint. You’ll want to get detailed information about the exact paint they’re using and the quantity they’re purchasing. Double-check with them to make sure they don’t water down paint as part of their painting process.

Of course, contractors can lie, or plead ignorance in the event their employees are caught watering down the paint that’s about to go on your home’s exterior. Get to the truth by asking them about their warranty. How long are they willing to stand by their work? If that contractor only offers a 1-2 year warranty—or, worse, no coverage at all—be careful. That’s a good sign that they themselves are not entirely sure how long your paint is going to hold up. Otherwise, they’d be willing to guarantee their paint.

A final tip: ask your contractor if they know the difference between watering down and thinning paint. If they don’t, you might want to find a more experienced contractor.

We do things the right way

At Crash of Rhinos Painting, we back our exterior paint with a 7-year warranty—far longer than state requirements. We’re that confident in the quality of our paint and our work.

Want to learn more about our painting process and get a free proposal? Or, do you have other questions about exterior paint? Click the button below to get started.