How to Make Interior Paint Into Exterior Paint?

Is it allowed to mix them? Is it safe to use exterior paint indoors? We will answer these and other questions today

Imagine the following situation: you decide to refresh your house’s facade or any other exterior object in your household by painting it.

You go to the store, buy paint and everything you need, and you start painting. But then, right in the middle of the process, you realize that you are running out of paint and you will not be able to finish your project!

What shall you do? The majority of us would think of the same thing: what if I use my interior paint leftovers to finish what I have started? Both paints have the same color so the difference will not be seen!

That might seem to be a brilliant idea, but here you have another question that comes into your mind. Is it possible and allowed at all to mix these two types of paint? Can you use interior paint outside?

And what happens if you use interior paint for the outside painting works?

Well, if you are not a professional painter, answering those questions might be quite complicated for you! This is why we decided to help you out a bit and provide with all the necessary information on the use of these two types of paint together in a mixture.

So from today’s article you will learn not only whether it is ok to mix interior and exterior paint. We will also tell you more about different nuances of the process, such as whether it is ok to mix oil-based and water-based paints, whether paint with different finishes can be combined successfully, and what happens if you mix two distinct brands of paint.

Finally, you will also learn about the major distinctions between interior and exterior paints, as well as find out which one of them is more durable.

All You Need to Know About Using Interior Paint Outside

If you started your home painting project and then you suddenly find out that you are running out of paint, you might think of the use of interior paint for the outside painting works. But then you will definitely ask yourself a question: is it possible to mix these two types of paint at all?

Well, the basic answer is yes. Exterior and interior paints can be mixed together or even used interchangeably.

However, it is still necessary to be aware of certain nuances and peculiarities of such a paint combination to be able to get the most out of it for your painting project.

First of all, you need to keep in mind that all the interior paints have a different formulation than exterior paints.

They are not designed for freeze and thaw, rain, snow, mold, and mildew! This is why they will chalk, fade, and even break down more quickly if applied outdoors.

Also, interior paints are more porous in comparison to the exterior ones, and they lack the necessary resin to bind them to exterior surfaces. As a result, they are more likely to crack and flake.

All You Need to Know About Using Interior Paint Outside
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In addition, exterior and interior paints have different amounts of VOCs (exterior paint has a much higher amount of them) which may have a harmful effect on you if you apply this paint indoors. See, these solvents are off-gas fumes that are particularly problematic for the respiratory system!

While you can get away using exterior paint inside a room or hallway, it will smell to high heaven, give you a headache, and potentially damage the lungs.

So if you must use exterior paint or a homemade mix of interior or exterior paint inside, keep it well ventilated, with fans and open windows. Also, it is important to keep in mind where and how the paint will be applied.

If you are determined to use interior paint outside, please remember that it should be sealed with one or two coats of exterior-grade, clear-coat sealer.

All You Need to Know About Using Interior Paint Outside (3)
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Depending on how strongly the painted surface will be exposed to the elements, it may extend the length of time it will adhere, but it will not necessarily prevent the paint layer from fading, and the sealer may yellow.

Using interior paint with a sealer increases the amount of work, and makes more expensive exterior paints a cheaper finish, that’s true. But additionally, using interior paint outdoors voids its warranty.

So before you reach for the interior paint uto have it used outside, consider all the nuances that we have mentioned.

Maybe, it will be better and wiser to just go to the store and buy some extra cans in case you will need more paint than you expected?
But if you do decide to make use of these two types of paints together, we recommend you become familiar with some more aspects regarding their use.

With this information in mind, you will understand better how the mixing process must happen and what you will need to take into consideration before you start combining the two paints in one.

All You Need to Know About Using Interior Paint Outside (2)
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Is It Allowed to Mix Paints With Different Finishes?

If you are going to mix two different types of paint, be very mindful of the type of paint you are using. Since there are many different types of paint, we would recommend you take some time in order to get to know your particular paint better.

So what are those types of paint we are talking about? Well, you can find the following ones on the market:

Matte Paints

The major significant feature of these paints is that they almost have no shine to them. It allows them to hide dimples and imperfections in walls and ceilings quite effectively.

However, you should avoid using this type of paint in the bathroom or kitchen since high humidity and splattering from your cooking can ruin the finish.

Matte Paints
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Eggshell Paints

Similar to matte paints, eggshell has just a bit more shine to them. They are also perfect for the same uses as the matte paints, by the way.

Eggshell Paints
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Satin Paints

This paint is more suitable for higher-traffic areas of the house, such as hallways or children’s rooms. Also, it gives an adorable satin-like finish to the painted surface.

Satin Paints
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Semi-Gloss Paints

Shiny and durable, semi-gloss paints are suitable for places like the bathroom, laundry room, and kitchen.

Semi Gloss Paints
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High-Gloss Paints

This type of paint is perfect for accent and furniture work since it will create an astonishing glossy look if the proper preparatory work is done.

With all this information in mind, now you are aware of whether you can mix your paints to end up with something similar to the original color and finish.

You can mix two paints with different finishes, but it will dull the reflectiveness and shine. For instance, you can mix a semi-gloss and satin paint and notice a small drop in the shine of the mixed product.

High Gloss Paints
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Depending on what you are using the paint for, this may not be a problem.

The same goes for mixing eggshell and matte or satin and eggshell. However, mixing the paints with completely different finishes like a matte and a high-gloss one, you will not have great results! It is just best to save those paints for smaller projects.

🖌️ Interior vs Exterior Paint (You CAN Use Either One!) 🖌️🖌️ Interior vs Exterior Paint (You CAN Use Either One!) 🖌️

Can Water-Based And Oil-Based Paints Be Mixed?

This question bothers many home renovators and painters. Indeed, is it possible to combine two paints that have different bases?

First of all, before we answer this question, we would like to remind you of the two basic types of paint bases that exist. Depending on the type of base, paints can be divided into two groups:

  • oil-based paints
  • water-based paints

Oil-based paints are the traditional long-lasting paints that can last for years before you decide they need repainting.

However, they off-gas much longer than water-based paints and take longer to dry. As for the water-based paints (or latex paints as they are also called), they are more modern, they dry faster, and they are less prone to show brush strokes and overlapping when fully cured.

However, you don’t want to mix these two types of paint together since, as you all definitely know, oil and water do not mix well together.

Can Water Based And Oil Based Paints Be Mixed
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Can I Mix Different Brands Of Paint?

With the brands of paint, it is somewhat more complicated. Indeed, if you decide to mix an interior and exterior paint that come from different brands, will there be that many distinctions between them except for the brand’s name?

Basically, there is nothing bad about mixing two paints of different brands. And if you do so, the effect will be quite good. However, we would like you to keep in mind that, first of all, paints contain four different components. Those components are:

  • Pigments – which are the crushed minerals that give the paint its color.
  • Solvents – the chemicals that are responsible for keeping paint in a solution.
  • Additives – the component of paint that controls its drying time and contains the mildewcide mentioned earlier.
  • Binders – the part of the paint that helps to form a layer.

So naturally, different paint brands have distinct recipes for their products, with different concentrations of the components mentioned above, and you need to consider that before you decide to mix two of them.

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When trying to mix two different paint brands, beware that even if the paints seem similar, they may not mix!

At the same time, it is very likely that you will find two brands that can be perfectly mixed together!

So what we would suggest is that you give it a try and mix the two paints of different brands that you have. And just see how it will work (if it will). Anyway, at least you will find out whether these two particular brands can be mixed together or not!

Can I Mix Different Brands Of Paint (2)
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What Is the Difference Between Interior And Exterior Paint?

Before you proceed with using interior paint outside, consider learning more about the basic distinctions that these two types of paint have. Of course, the basic distinction is that one type of paint is designed for the outdoor use whilst another one is meant for the indoor application. But except for that, there are three more distinct factors that are connected with the paint content and that must be taken into account.

  • pigments
  • binders
  • liquids

Now let’s take a closer look at each of them. So, let us start with pigments.

Pigment is what provides a can of paint with its color. Interior paints may contain organic pigments for giving them color, and certain types of organic pigments are known to significantly fade if used on an exterior surface.

As for the exterior paint formulas, they avoid these pigments which increases the time needed between outdoor paint projects.

What Is the Difference Between Interior And Exterior Paint
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Then we have binders. Those are additives that are used to bind the pigment together, as well as provide adhesion to the painted surface.

And since exterior paints usually need more help with fighting the impact of the environment and weather, binders used in outdoor-friendly formulas give the paint resistance to such problems as cracking and chalking.

Also, they provide an increased moisture control. Interior paint binders, on the other hand, may offer better resistance from abrasion, which is not that much-needed quality for exterior paints.

Finally, paints may vary depending on the types of liquids they contain. As for the interior paints, specifically indoor water-based paints including latex, they contain the lowest levels of VOCs (volatile organic compounds).

VOCs are used as solvents in the liquid component of paint and they vaporize at room temperature. And since they are connected to many health issues from headaches to even cancer, look for the paint that has low or no VOC level.

Respectively, exterior paints contain higher levels of these harmful components since they are designed for outdoor use. This is why, when you decide to mix these two paints, take as little of exterior paint as possible and remember to ventilate the painted area properly!

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What Paint Is More Durable: Exterior Or Interior One?

If you think of interior paint being used outside, you might be wondering how durable it is, and which of the two types of paint is more long lasting when applied outdoors.

The answer is that the exterior paint is generally considered more durable than interior paint. See, exterior paint is designed to withstand wind, rain, snow, ice, and hurricanes, as well as other harsh weather conditions.

Interior paint, on the other hand, has a higher degree of hardness than exterior paint.

What Paint Is More Durable Exterior Or Interior One
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Hardness helps prevent the paint from scuffing. It also allows us to clean the paint easily. But any interior paint will not withstand weather fluctuations long enough if you apply it solely on your exterior walls.

Nevertheless, exterior paint is not as hard as interior paint, but it is more durable.

Frequently Asked Questions

⭐How long will interior paint last outside?

It depends on weather conditions in your area, but expect it to last for a couple of years.

⭐ Can I use pure interior paint outside if I seal it?

Yes, you can use it like this.

⭐ Can I use interior paint outside as a primer?

No, since they serve for different purposes.

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