How to Thin Paint for Wagner Sprayer

One of the biggest reasons a hobby or cheaper paint sprayer has issues is because the paint isn’t thinned correctly. So here’s how to thin paint for a Wagner Sprayer. No more guessing, straight up, here’s how to thin it right!

This step-by-step tutorial uses the Wagner Double Duty Paint Sprayer.

Learn exactly how to use a Wagner Double Duty Paint Sprayer here!

thinning paint for a paint sprayer

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We’ve received so many questions about our Wagner Paint Sprayer that we decided we needed to dedicate a series of posts on how to use a paint sprayer to refinish furniture.

I could never go back to brushing our paint on all of the pieces we refinish.

Not only does it make painting easier and faster, but it also creates that smooth even finish you see in stores.

Today we’re talking about our Wagner Paint Sprayer, what we love about it, as well as how to thin chalk paint or latex paint for the sprayer.

Do You Have to Thin Paint for a Wagner Sprayer?


Actually, most beginner or hobby paint sprayers require the paint to be thinned because they don’t have enough power to suck up and push out anything thicker than stain.

But, thinning the paint a little bit is even a good idea with a professional grade paint sprayer too – it creates a prettier, less bumpy finish!

(Update: The Wagner FLEXiO sprayer doesn’t require paint to be thinned! It can spray thick chalk paint! Check out the comparison here!)

It’s not rocket science, and the way that I’m about to show you how to thin paint, is a no guessing method!

But first,

Wagner Double Duty Paint Sprayer

When we started painting furniture, we didn’t have any outdoor space to paint in, except for our apartment balcony or the shared entry way.

We lived that way for over a year while we brushed everything on.

When we moved to a home with a garage and a decent sized backyard I was over the moon!

I quickly started researching paint sprayers and had so many questions about how to use them and which one to get.

After talking with my sister and mom who have paint sprayers I decided on the Wagner Double Duty Paint Sprayer.

I’m so glad I did!

spraying a desk with a wagner paint sprayer

Supplies Needed:

How to Thin Paint for a Wagner Sprayer

  1. Filter the Paint
  2. Add Water (Or the Correct Thinning Agent for Your Paint)
  3. Test with Viscosity Cup

Step One: Filter the Paint

Pour the paint into the paint sprayer container, using a fine mesh strainer to remove any dried paint lumps.

paint filter to filter paint for paint sprayer
pouring chalk paint through paint filter

Those lumps will clog the paint sprayer while spraying and will make it a nightmare so it is best to make sure all of those are removed from your paint before you start spraying.  

Trust me on this one.

Step Two: Add Water (Or the Correct Thinning Agent for Your Paint)

Next, you’ll want to add a small amount of water (if using water-based paint!) and whisk the paint and water to combine.

*NOTE: If you are using oil-based paint, use paint thinner to thin the paint.

Keep doing this until you think it’s the right consistency.

Since every paint varies in thickness, there isn’t an exact amount of water to add to the paint.

adding water to chalk paint

You’ll want to only add a small amount of water at a time because if you add too much water you will have to add more paint.

Usually, I’ve already cleaned my strainer and closed up the can of paint, so it’s much easier to just add water slowly and test as much as I need to until it’s the right consistency.

Step Three: Test with Viscosity Cup

When you think you have it about right, grab the viscosity cup and the timer or stopwatch.

To test if the paint is the right consistency for the sprayer, dip the cup completely into the paint and start your timer or stopwatch as you bring the cup up out of the paint.

wagner viscosity cup
paint draining through viscosity cup

You are looking for the paint to completely run out of the bottom of the cup within 25-40 seconds.

I prefer the consistency of 35 seconds, but as little as 25 or as much as 40 seconds works too.

timing how long paint takes to drain from viscosity cup

Once I have the right consistency I wash off all the tools for next time and screw the head of the paint sprayer onto the container.

That’s all there is to it!

Super easy and can be done pretty quickly.

I hope this answered all of those questions, and if I made more questions for you please let me know!

How to Get Away With NOT Thinning Paint

If you don’t want to thin out the paint, use the Wagner FLEXiO paint sprayer instead of the Wagner Double Duty Paint Sprayer. It can spray thick chalk paint without thinning it out! (I like to add water still to make the finish look perfectly smooth and not bumpy.) See it in action with this blue painted nightstands makeover.

What’s so great about the Wagner Double Duty Paint Sprayer?

  • I love that it comes with two containers. Since I’m always using it I end up keeping a constant supply of poly in the small container and change out the color of paint in the big container.
  • No air compressor needed. This baby has its own little compressor built-in, so there is no need to spend hundreds of dollars on a big enough air compressor to run your spray gun.
  • It’s easy to take apart and clean out. This is a must as I’m constantly cleaning this bad boy.
  • My favorite part is that it is reasonably priced – especially when you take into account the other paint sprayers that have to be connected to an expensive and huge air compressor.
  • Not only do I love my paint sprayer, but I love how quickly it paints my furniture. You know the dreaded white paint that takes 5 coats before you get complete coverage? I would dread brushing all of those layers on before. Now painting everything white isn’t so bad since those 5 coats each go on in seconds. Now I get to do other things while I wait for the paint to dry. Who wouldn’t want that?!

So basically if you don’t have a Wagner spray gun already, I highly recommend them!

And no, I’m not getting compensated by Wagner to say that. This is completely my opinion and I purchased this spray gun on my own.

UPDATE: Learn more about the pros and cons of this Wagner Double Duty Paint Sprayer here!

What kind of paint do I use?!

I personally love chalk paint.

We do however have to use a top coat over the chalk paint, but honestly, who likes the feel of dried latex paint on their furniture? Not me! 

Polyurethane gives the furniture a nice smooth finish – just like the finishes at the store.  So it’s a win win!

And, you can spray polyurethane with this paint sprayer too!

My favorite budget friendly paint is Behr paint made into homemade chalk paint.

I love the color variety it provides as well as how easy it is to get.

I’ve also used Country Chic Paint quite a bit, and it’s amazing.

UPDATE: Learn about my favorite and the Best Paint to Use on Furniture here!

No matter what paint you use, latex, chalk, acrylic, enamel, etc. – it has to be thinned.

I know it can be intimidating, but once you’ve done it once or twice it is easy as pie.

For those who like to see visuals, I made a little video to show you how I thin my paint for my paint sprayer.

More Paint Sprayer Tips and Reviews:

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  1. Sroor9001 says:

    So you should have viscosity cup
    There is no other way to measure ��

  2. That's the only way I know how to get an accurate measurement.

  3. Mark A Bradley says:

    Thank you for the video,you are using the same paint as I am. This helped me out BIGTIME,thank you….

    1. I’m so glad! Happy painting!

  4. Hello! I plan on buying the sprayer you have suggested. Where do I get a viscosity cup like yours?

    1. Hey Tracey! I’m excited for you! The paint sprayer I use comes with the viscosity cup! Thats one of the many reasons I love it!
      Can’t wait for you to bust out your new sprayer!

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