
Rustoleum is a well-known paint brand that’s nearly a century old. It has become quite popular over time for its rust-proofing capabilities.
Today, many metal surfaces ranging from ships to roofs to equipment to vehicles, and more are covered in Rustoleum spray paint.
While there are spray cans available, for painting larger surfaces, you will need to buy the paint in quantity and mix it properly for spraying.
Below we will look at what to use for diluting the Rustoleum paint and how to do so correctly to achieve the desired results that last. Let’s start by knowing some basics…
What is Rustoleum Paint?
Rust-Oleum paint is a product that Robert Fergusson invented in 1921.
A sea captain by trade, he noticed that when fish oil was spilled on the rusted metal deck of his boat, the rust did not spread.
At first, he mixed whale oil with paint to achieve the desired results, but the formula changed considerably over time.
Instead of whale oil, Rustoleum now contains polyurethanes, latex, epoxies, and Alkyds – to name just a few ingredients.
What Type of Paint is Rustoleum?
Rustoleum is one of the most popular acrylic enamel rust-preventative spray paint today.
This multipurpose paint stands number one in terms of the paint industry’s professional, specialty, and decorative segments.
Until 1994 Rustoleum was a family-owned company, but now it’s part of RPM International Inc.
Although nearly 100 years old, Rustoleum is still quite a popular brand in the US and Canada, and the company itself has reached over a billion dollars in sales.
The company’s success starts with its remarkable product, but it also continues with the different ways it is packaged.
So popular is Rustoleum that people use the paint even for larger projects that use a spray gun like Wagner.
You can always use a paintbrush if you do not want to thin it, but thinning and putting the paint in a sprayer gun will make the job go faster.

Steps for Thinning Rustoleum Paint for Spraying
Rust-Oleum comes in spray cans, which work fine for small to medium-sized surfaces.
However, if you want to paint something large (such as a furniture set, vehicle, tractor, or other industrial equipment), you are better off purchasing Rustoleum in a paint container and thinning it with proper solvent before using your spray gun.
For thinning Rust-Oleum, you will need:
- A large bucket to hold the paint
- A wooden stirring stick
- Paint and solvent for thinning
Once you are ready, all you need to follow the three easy steps;
Step 1- Pour and Stir
Pour a gallon of Rustoleum into a bucket that’s at least 1 ½ to 2 gallons big. This is because you’ll need to stir the paint.
Next, pour about 6 ½ ounces of acetone into the bucket and mix with a wooden stick.
Stir with a wooden stick until you feel the paint starts to thin and keep going until you have reached the desired consistency.
Step 2- Test the Paint
Before you spray, it’s good to test the thinned paint to see if it works correctly in your spray gun.
If needed, use a viscometer to measure the paint’s viscosity. Or, add a small amount of paint to the spray gun and test it on an unwanted surface, such as scrap metal.
Then judge the results and color with the help of a paint mixing chart.
If required, add more acetone or more paint, depending on if you need it thinner or thicker – to get the right color (lighter or darker).
Step 3- Load The Sprayer
Once you have reached the desired viscosity, fully load your airless sprayer and start applying the paint.
Be sure to follow the instructions on the spray gun, wear the appropriate protection, and hold the gun at enough distance to cover a decent-sized area while still being close enough to add a good layer of paint.
If you use the viscosimeter, you can record the results and rely on that again if you decide at another time to thin some more Rustoleum.
The bottom line
Thinning Rust-Oleum paints like Tremclad is no rocket science if you know the process and the right kind of products to use.
The best way to thin Rustoleum oil-based paint for spraying is to mix 6.5 ounces of acetone for every gallon of paint.
Alternatively, you can mix it with mineral spirits or xylene in a ratio of 6 to 6.5 grams of thinner for every gallon of paint.
No matter whether you are mixing Rustoleum paint colors or using a single one, follow the above guidelines.
Hopefully, these will help you complete your task quickly without wasting your paint, thinning agents, and energy.
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Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.