Perhaps you want to apply oil-based paint, but you don’t know to go about it.

The steps are pretty simple, and I will reveal them to you.

In this article, I will show five appropriate ways to thin an oil-based spray paint for a spray gun.

I will also add a bonus by showing you how to handle a spray gun when painting.

How to thin oil-based paint for a spray gun.

Find out whether the paint you bought can be applied to a spray gun.

This is very crucial because not oil-based paint can be thinned for a spray gun.

After researching and knowing that your paint can be applied, you might as well check if the paint has a specified ratio of thinner to utilize.

Once you have taken cognizance of these two steps, you have done 50% of the job already.

Items needed you to apply oil-based paint for a spray gun.

You need a few tools to use oil-based paint that will make the job quicker and easier.

These tools include;

  1. Paint thinning agent.
  2. A paint strainer.
  3. A funnel.
  4. A clean bucket.
  5. Stir sticks.
  6. A spray gun.

Now that you have the tools, let’s get down to business;

Step 1: Ready your paint.To get rid of any impurities or paint lumps, strain your paint using a strainer.
Step 2: Add thinner.Add 1 part thinning agent to the paint you are using.
Step 3: Stir paint.If it has not been thinned enough, add another 1 part thinner and keep testing until it passes.
Step 4: Test run.Apply the paint through a funnel to check if it has been thinned enough.
Step 5: Re-thinTo remove any impurities or paint lumps, strain your paint using a strainer.

Step 1:

Ready your paint:

To get your paint ready, you need the buckets and the strainer.

In almost every new paint bucket, there is always a chunk of paint clustered together.

Getting paint lumps like this to pass through a spray gun is complicated.

This is why you must flood the oil-based paint into a bowl with a strainer.

While the paint will escape through the strainer’s holes, the paint chunks won’t be that lucky.

Step 2:

Add thinner:

This is the most crucial and delicate part of the process that you are thinning your paint.

You must be more careful because if the thinner you add is not enough, the paint will remain ‘fat’.

But if you use too much thinner, the paint gets watery and extremely light.

(We don’t want to fall victim to our red and pink paint scenario).

When you want to add thinner (mineral spirits or turpentine), the best option is to follow the directions on the paint.

Most paints have the thinner they require to be thinned on their label.

Without any instruction, the general rule is to add 1 part thinner for every 3 parts of paint.

Applying thinner than the paint would be better for the bottom line.

If you do that, you are not thinning your paint; you are painting it thinner (Lol).

Step 3:

Stir paint:

This is where the stir stick comes in handy.

Carefully and thoroughly stir the paint and the thinner together.

Ensure you stir it properly until your thinner and paint get mixed totally.

If you get bored while stirring, sing (roll, roll, roll your boat while stirring).

That’s my super-secret of having fun while stirring.

“Ensure your stir stick is clean. You do not want to add particles that the strainer should have removed.”

Step 4:

Test run:

There is a sure way to test if your paint is thin enough for your spray gun.

Simply pour the thinned oil-based paint into a funnel.

If it flows freely, your job is done, but if It doesn’t, you will have to go to step 5, which is to…

Step 5:


You have to add one more part thinner to the oil-based paint to make it thinner.

However, this may slightly make the paint light and take longer to dry.

But don’t worry; it will not be as worse as the ‘red and pink paint scenario’.

It is only a small price to pay, and you’d be glad you did it when you started spraying.

After adding the thinner, thoroughly mix your paint and thinner with another clean stir stick.

Then, the test again checks if your paint passes through the funnel.

If it does, you are ready to start spraying; if it doesn’t, continue to add thinner until it passes the test.

Watch this video if you want to watch how these steps happen in action.

Disclaimers: I must warn you that when using oil-based paint, ensure you are doing so in a well-ventilated area.

Wear a mask, gloves, and safety goggles to minimize potential health risks.

Oil-based paint contains high volatile organic compound (VOC) levels, which, when it vaporizes, can cause smog and other quality problems.

Professional tip

These are tips that professionals use to make their painting jobs flawless.

Tip 1-

The steps for thinning oil-based paint and primers are similar to diluting them.

Most often than not, these steps are always on the can first, so simply following them will bring immaculate results.

Tip 2-

The temperature at which you are working affects your paint thinning significantly.

You might have noticed that when you are using cold paint, it usually appears to be thicker than it is.

It is safer to mix the paint at room temperature; this will ensure that you get the desired result out of your paint thinning process wasting your paint.

Types of thinners to use when thinning oil-based paint.

In thinning oil-based paint, some conditions determine what thinners to use.

For instance, if the previous surface you want to spray paint on consists of thick or oil paint, it is not advisable to use solvents.

This will cause your paint to sink and even cause massive breaking.

Thinners you can use to thin oil-based paint include;

  • Mineral spirits.
  • Turpentine.
  • Linseed oil.
  • Walnut oil.
  • Poppy oil.
  • Safflower oil.
  • Stand oil.

Each thinner has its level of viscosity on the oil-based paint.

This table will show you a simplified form of these thinners.

ThinnerType of thinnerViscosity/thicknessDrying time
Mineral spiritSolventLowNormal
Linseed oilOilMediumSlow
Walnut oilOilMediumSlow
Safflower oilOilMediumVery slow
Stand oilOilHighSlow
Poppy oilOilMediumVery slow

It will also show you how long they take to dry when used and their viscosity level.

This table shows that using oil to thin oil-based paint increases the paint’s viscosity but takes a longer time to dry.

However, solvents decrease the paint’s viscosity but take a shorter time to dry.

When to use solvent to thin oil-based paint.

You must know when to use solvents to thin oil-based paint.

This is important because thinners have their benefits when you use them to thin oil-based paint.

If you are laying your first coat, then it is advisable to use solvents to thin your oil-based paint.

Solvents thin the paint rapidly and thoroughly.

They also have low viscosity, which makes the oil-based paint more watery.

Solvents like acetone also help remove oil-based paint.

Safety precaution: Solvents have narcotic effects, they can cause dizziness, fatigue, and even unconsciousness.

Make sure you wear a mask when using solvents to thin your oil-based paint.

When to use oil to thin oil-based paint.

It seems redundant to thin oil-based paint with oil.

But if you have applied your first layer, it is better to use oil to thin your paint for the subsequent layers.

This is because these solvents will make the oil-based paint sink if applied on a surface with oil.

Although the paint will take longer to dry, it is a small price compared to sinking and breaking your paint.

You don’t want to waste your expensive paint and produce a bad result.

How to use a spray gun to spray oil-based paint.

Remember the bonus I promised you?

Here it is.

To use a spray gun, follow these steps.

Step 1:

Prepare your oil-based paint for coating:

To prepare your oil-based paint for coating, carefully strain out the paint lumps.

Lumps like this cannot pass through the spray gun’s nozzle, so you need to strain these lumps.

To do this, get a bucket and a strainer.

Put the strainer on the bucket and use a strainer to sieve out the paint lumps.

After straining, thin the paint using a thinning agent, as discussed earlier.

Step 2:

Prepare the surface you want to paint on:

This is just as important as preparing the oil-based paint for coating.

The general rule is to ensure that you completely wipe out any dust on the surface.

You can do this using a thinner.

However, some coatings have technical data sheet that shows how to prepare specific surfaces.

Step 3:

Choose the right fluid tip and/or air cap:

The essential next step is to review the cap and nozzle options on the spray gun.

You must select the best size suitable for the paint you are spraying.

One way to do this is by performing a few test patterns until you have gotten the one you are comfortable with.

You need to be sure that the paint comes out with the right speed and in a fair quantity.

If your spray gun has one option, move to the next step.

Step 4:

Adjust the air pressure:

This step requires technical fine-tuning.

You need to ensure you get the right amount of breaks you need to get.

You can watch this video to see how it is done.

Step 5:

Use the proper method:

While painting with your spray gun, keep the spray gun about 5-7 inches away from the surface you are painting.

You also want to move back and forth and ensure you are not swinging your waist while spraying.

You must do all these to ensure a suitable method for an excellent finish.

Step 6:


Paint a part of the surface area with the method listed above.

If you are satisfied with how the painting looks, you can continue to spray the other parts with the method you used in Step 5.

Step 7:

Clean your gun:

(Oh, I mean, clean your spray gun.)

When you are done painting, clean your spray gun thoroughly.

Remember you are dealing with oil-based paint, so you need a solvent to clean it.

Ensure you clean the air cap and nozzle as well.

How to use an HVLP spray gun for thinned oil-based paint.

To use a high volume low-pressure spray gun, follow these steps;

Step 1:

Check and clean filters:

You need to check the filters of the HVLP spray gun.

To clean any dirt or dust on it.

Step 2-

Connect the spray gun to the power supply.

Step 3-

Connect the airline to the unit.

Step 4-

Pour the thinned paint into the HVLP spray gun‘s container.

Step 5-

Check the air nozzle:

You want to check if the air nozzle is right for the application.

The air nozzle should be suitable for the paint you want to spray.

Step 6-

Connect the air hose to the spray gun.

Step 7-

Adjust fluid control:

You need to adjust the control of the spray gun’s fluid.

This is to ensure you have the right amount of fluid flow.

Step 8-

Screw out for more paint:

If you want more paint to flow out while spraying.

Simply screw out the spray gun.

Step 9-

Ensure the valve is fitted to the pressurized pot.

Step 10-

Adjust air cap tip:

Adjust the air cap tip to the spray pattern you desire.

How to use an airless spray gun for thinned oil-based paint.

How to use an HVLP spray gun for thinned oil-based paint

Step 1;

Thin your enamel or oil-based paint:

I have shown you how to do this earlier.

Step 2;

Choose the right tip for the paint:

Find the right tip for oil-based paint.

There are different tips for different paints.

You need to find the right one suitable for your enamel paint.

Step 3;

Submerge the suction tube into the thinned paint:

The airless spray gun has suction and a return tube.

To test and relieve the pressure of the spray, submerge the suction tube into the paint you thinned.

Put a bucket beside the thinned paint container.

Step 4;

Change the spray/prime knob from spray to prime:

You want to suck the paint into the spray gun.

Change the spray/prime knob from spray to prime.

If it is already on prime, let it remain that way.

Step 5;

Adjust the pressure settings:

I recommend you adjust the paint set to 2 or, at most, 2.5

Step 6;

Squeeze the trigger:

Test the spray gun’s setting by squeezing the trigger.

Ensure the return tube is inside the bucket you placed beside the thinned paint.

Step 7;

Lock the trigger:

Once you have got the paint flowing through the gun.

Then lock the trigger.

Step 8;

Install the tip:

Ensure you install the tip suitable for the paint you are spraying.

Let the tip be facing the direction you want to paint.

Step 9;

Change the spray/prime knob from to spray:

Since you are about to spray, change the knob back to spray.

Step 10;

Adjust the pressure setting and unlock the trigger:

Adjust the spray settings to whatever is required by the painting manual.

Unlock the trigger since you are now ready to paint.

Step 11;

Test the spray gun:

You want to test your airless spray gun on cardboard to know whether or not you are satisfied with the coat.

Step 12;

Use the proper method:

Hold your spray gun 10-12 inches from your painting surface, and do not swing your wrist while painting.

Professional tip

Apply your paint in a consistent pattern and overlap by 50%.

This will make your job easier and more pleasant to look at.

Disclaimer: this is not a general rule to follow for all airless sprayers.

Airless sprayers can vary; ensure you read the material for the airless sprayer you are using.

Final thoughts:

I have always wondered why you need to thin oil-based paint for a spray gun with thinners, not water.

The reason is simply that oil doesn’t mix with water.

You need to thin oil-based with thinners specifically because they are highly viscous.

Thinners, as the name imply, help to reduce the viscosity of the oil-based paint and make it easier to spray with a spray gun.

I hope you find this article helpful to thin your oil-based paint for a spray gun.