Acetone and Paint thinner what the correct solvent to use

Paint thinner vs Acetone {and other solvents} – How and When to Use Each

Are you confused which is the right product to thin paint.  We have all been told to use paint thinner and acetone interchangeably to thin paint.

And rightly so, both do the job well and used for similar applications. As the name suggests you should ideally go with the paint thinner product. But that might be an oversimplification. Let’s dig in to understand it a bit more.

For one, you would have noticed a difference in the price.

First thing first. Both paint thinner and acetone are solvents.  Painting experts use the right solvent for the right job and use the right technique when applying it.

On the other hand, DIYers often use any solvent and risk damaging the tool, surface and end up with a sloppy work.

What are the Different Types of Solvents that You Will Come Across

  • Turpentine
  • Mineral spirits (A.K.A white spirits’)
  • Acetone
  • Naphtha
  • Alcohol (and its many forms such as methyl, isopropyl, ethyl, denatured alcohol etc.)
  • Lacquer Thinner (combines multiple solvents, may also include Acetone)
  • Acetone
  • Methylene chloride

and the list goes on….

There are a variety of different solvents.  What you need to understand is each has a slightly different set of properties.  

One might be strong, and a similar product might have lesser strength. Another solvent can smell too much and manufacturers might work on an odorless variety of the same for a slightly higher price.

All in all, you must think of the below properties

  • speed of evaporation
  • The strength of the product
  • Intended use (as a thinner or as a solvent)
  • Material that it must be applied on

This will dictate when and where to use.

Protection Before Using Paint Thinner, Acetone or Other Solvents

I have seen many DIYers over my career that uses the product without proper protection.

In general, if you don’t know what to use and how to protect, that is an issue.  Read the container for manufacturers recommendation.

Manufacturer’s recommendations are just the bare minimum, so you are fine over protecting than under protecting.

Many are stronger chemicals with dissolving, diluting, thinning and stripping abilities. Several of these products can irritate your skin too.

First, they can be absorbed by the pores in the skin and can travel to other organs.

I know you didn’t even image this, right?

Second, they can cause dermatitis.  Which is basically causing irritation to the skin by removing the natural oil in the skin and causing skin allergies and irritation.

The best protection is to use gloves all the time when dealing with solvents.  And a face mask that filters out the air. After all the solvents are known to have a very strong smell that gives headaches to some.

Not any gloves, but the ones that are designed to protect against chemicals.

Paint thinners and any solvent for that matter have strong chemicals.  Most of them are hazardous and some of which leave fumes. As you know solves can quickly evaporate in the air so you will almost always inhale if you don’t have a well-ventilated space. In addition to keeping it ventilated you can use a respirator to combat this problem.

Inhaling strong chemical fumes can cause headaches, dizziness, vomit and can even lead to unconsciousness.  There are even cases of death in prolonged exposure to certain toxic hazardous chemicals.

Difference Between Thinner and Solvent

Let me talk about the difference between a thinner and a solvent.

For example, let’s say you have dried shellac in a cup – just a left over.  If you try to rinse it with water, nothing will happen.

But if you pour a little of denatured alcohol in it and let it sit, you will start to see that dried shellac getting loosening up and solve into alcohol.

Paint Thinner Uses

Main uses of paint thinner, as the name suggests, is to thin the paint.  There are different applications where you might need the paint in certain consistency to get the correct spread.

Mostly you would use the paint thinner to get the consistency right when the weather thickens it.

The other main use is to clean the brush-up.  There are other products where you might get the dried brush cleaned, but when it’s wet, you would use paint thinner to clean the brush.

Paint thinners are best used with oil-based paint and especially when it is wet if you want to clean.

If you are working with latex paint, ignore using paint thinners. They are not good enough as a thinner or as a solvent when it comes to latex paint, lacquer, shellac and such.

Paint Thinner Ingredients

Mineral spirits are also called white spirits.  This is the most common item you will be referring to as paint thinner.  If you want to get too technical, you may say mineral spirits is more refined than paint thinner.

For all intents and purposes and you all DIYers, the difference between paint thinner and Mineral Spirits is negligible.

Back in the day when all paints were oil based, mineral spirits were used primarily.

This is going to be your go-to thinner for most varnish and oil-based paint thinning.

Mineral Spirits might not be fast evaporating compared to Naptha for example.

Other than Acetone and Denatured alcohol, most of what we will see are petroleum-based products.

Paint to Thinner Ratio For Paint Gun

The best is to look at the manufacturer’s recommendation. Either on the label of the container or online.  Usually, in my experience a 3 part to 1 is the most that must be used.

We have also heard 4:1 ratio of paint to thinner by other expert painters.

Remember one thing, the thinner you add, it may feel as though that you got a good runny consistency.  But what happens is that you are compromising on the coverage.

Paint, in general, has a base and a lot of color pigments, that gives you the color on the surface when you apply.  When you add paint thinner, you are basically making the pigment count less per unit of thinned paint.

Acetone to Thin Paint

Acetone is a fast drying product and it is not oily.  It’s a great degreaser and a thinner. And this is also the fast evaporating solvent.

So if you have an application to clean fast and not leave a residue then acetone is great.

This is a great metal finishing cleaner.

If you have sticker residue or any leftover glue product, acetone is great at removing it. Especially if you working with superglue or any other super strong glue product, before the glue dries, use acetone to remove the glue.

Also if are working with wood and find an oily residue acetone will be a great product to strip the oil out of the wood.

Be careful when using it on PVC products.  Acetone acts as a solvent and tries to etch the PVC. So don’t drain it in the sewer.

Acetone works nicely as a thinner if you are working with fiberglass products, mostly fiberglass resin.

Don’t believe me when I say Acetone can melt plastics, styrofoam and fiberglass resin, then you must watch this video.

Denatured Alcohol and Its Uses

It’s the same thing that’s in booze but some poison is added to it on purpose so we don’t consume — and yet no alcohol tax is paid.

Denatured alcohol is also a fast drying product, similar to Acetone. And this will also not leave a residue after the application is over and alcohol dried.

Acts as a Thinner and Solvent for Shellac. Use this to remove any ink marks easily.

Again if you are working on a wood product, use Denatured alcohol to clean it after sanding.

You can use it to clean windows – remember this leaves no marks.  

Well, use this as a degreaser too.

In Conclusion:

Using a paint thinner to thin the paint is the right approach.  However, if you are working with certain products and needs cleaned, acetone might do the job.

But several solvents act as thinner too.  So, you need to consider the paint product that you are using, the material that it is applied on before considering what to use as a paint thinner.

Acetone is definitely a cleaner which leaves no marks.  But on occasions, you can use it as a thinner.

There are several products to easily get confused.  You will also mess up the surface or the finish if you don’t know when and what to use. So it is recommended to read the label to see the solvent intended purpose to stay clear.

Or if it was me, I would as a local painting expert near me to be absolutely sure before using a product not intended for something.