Do you have some leftover paint you would like to use on your next project? Are you now hesitant to use the old paint because it had separated into layers when you opened it? Do not worry; this article will help you figure out the right thing to do.
There are instances where you only need a few DIY steps to make paint that has separated in the can fit for use. You may also have to discard the paint if it has gone bad.
Your concern is called for; the last thing you want is a bad paint job that will begin to peel and crack in no time. Bad paint could be more than an eyesore. Latex paint that has gone bad will also cause the room to have a terrible odor that worsens over time.
This article will explain what you need to know about reusing your old paint. We will answer questions like:
- Why does paint separate in the can
- How to reuse paint that has separated in a can
- How long different types of can last
- How to tell if the paint has gone bad
- How to store paint to prevent it from going bad
Why Does Paint Separate in the Can
Float is the painting industry’s term for the condition where your paint separates into layers. Separation is most likely to happen in colors that are formulated using pigments that have a large variance in densities.
For example, the color gray is formed using white and black pigments with densities of 3.4 and 1.62, respectively. When your paint is still for a long time, gravity causes the pigment with the larger density to settle at the bottom and the lighter one to float on top.
Float does not indicate that your paint is spoilt. It only happens because of the different pigments that separate the color over time. If your paint does not exhibit any of the symptoms that we highlight below, it should be good to use.
How to Check If Your Paint Is Bad
Contrary to popular belief, paint separation is not a telltale sign that paint has gone bad. There are several other signs that indicate a can of paint is ready for disposal.
1) How Does it Smell?
If you are hit by a rancid odor the second you pry off the lid, your can of paint has likely gone bad. Good paint still fit for use should have a chemical smell from the gases it emits.
2) What Is Its Consistency?
You are right to be alarmed if your paint’s consistency displays the following:
- Lumps that do not break apart when you stir or a rubbery layer at the
- Thin hard skin on its surface
- Separation into semi-transparent and opaque layers. If your paint keeps separating after layers when you remix it, you should dispose of it. Your paint’s failure to reconstitute the original consistency means that the solvent and pigment can no longer collaborate to stick on your wall effectively.
All of these signs individually indicate that your paint is not spoilt. If the lumps, thin skin, and float occur alongside a terrible smell, there will be confirmation that the paint is spoilt.
3) How Was It Stored?
Most types of paints can for years without spoiling if stored correctly. Exposing your paint cans to weather elements like rain or snow will increase their chances of going bad. Exposure to moisture may cause the paint can to rust. A rusted can may compromise the shelf life of the paint and causes it to go bad faster.
Similarly, paint that appears moldy should not be used. It will do more harm than good. Freezing temperatures, on the hand, cause the water in your paint to separate from the mixture causing it to dry out. Paint that has frozen is not fit for use.
Shelf Life of Various Types of Paint
Not all types of paints are manufactured to have the same shelf life. Before determining whether the paint has gone bad, we shall highlight the shelf life of various types of paint. So, how do you determine whether a can of paint is past its prime if there isn’t any expiry date on it?
1) Latex Paint
Latex paint can last from two to ten years. How long your paint remains usable will depend on how you store it. Since latex paint is water-based, it is more vulnerable to freezing. Anyone living in a cold region should store their latex paint in a climate-controlled area to prevent it from freezing. When latex paint undergoes freezing and thawing, it forms lumps that may be difficult or impossible to stir out.
2) Oil-Based Acrylic Paint
Oil-based paint has the longest lifespan. If unopened, it can last for fifteen years. An opened can that is well stored will last about ten years. Oil-based paint is the most likely to separate into layers over time. This is because it contains volatile organic compounds. These compounds separate, with the heavier ones settling at the bottom.
Ensure your acrylic paint is well sealed before you store it. Any exposure to air will dry the paint and emit toxic volatile fumes.
How to Reuse Paint That Has Separated
Before reusing your separated paint, ensure it has not gone bad.
- If your separated paint is still fit for use, your first step will be to determine whether the paint particles and solvent have permanently separated. If the paint has formed a thin hard skin, ensure you skim it off.
- Mix the paint thoroughly until it has a uniform consistency, i.e., the layers have completely blended into one.
- Check the paint’s color after stirring. If it does not regain its original color after blending, the odds that the paint has gone bad increase.
- Find a clean container to pour the paint into so you can inspect the bottom of the paint can. If the bottom has a rubbery, solidified layer of paint that fails to blend in with the rest of the paint. When the rubbery layer fails to mix in with the rest of the paint, you will have to throw out the paint. Ensure you throw out paint according to your local regulations to avoid getting a ticket.
- The paint will be ready for use when the paint and solvent blend smoothly without any lumps or chips.
- If you notice that your paint has lumps or chips, you will have to strain it before using it. Failure to strain the paint will cause the lumps and chips to stick out, preventing your paint job from having a smooth finish.
- You can purchase strainers at your local hardware store or improvise at home with a pair of stockings. Strain the paint into a clean container in small batches.
- After straining your paint, try brushing it on a newspaper sheet to check whether it will be smooth or rough and bumpy. If the paint is rough and bumpy, you should throw it out even after straining. Ensure you dispose of the paint as recommended in your region.
- If your separated paint makes it through all these steps, you can use it without worry. You must keep stirring the paint during the entire painting process. If the paint rests for too long, it will begin to float again. Ensure that your paint maintains a uniform color and consistency throughout the entire process.
How to Store Paint
Proper storage will ensure you preserve your paint for as long as possible. When storing your paint, be sure to:
- Put the lid back on the paint as soon as possible.
- Clean the lid and rim to ensure your reseal is airtight.
- Store the paint away from direct sunlight and freezing temperatures.
- Store the paint away from moisture.
- If you are storing leftover paint in a container other than the original can, choose one that is as close as possible to the amount of leftover paint. This limits air exposure and lengthens the lifespan of the paint.
How to Get Rid of Old Paint
Paint is classified as a toxic substance, and most regions have ordinances that regulate its disposal. If your paint is no longer fit for use, you may get in trouble if you simply toss it in the trash. Inquire about the laws of your region on disposing of paint to avoid a hefty fine.
If your paint has separated in the can, do not rush to throw it out. It may still be usable. If you do not smell a foul odor when you open the can, you can look closer at the can. Your paint may be usable where the can show no signs of mold, rust, or damage. The final test is to check whether layers contain any lumps and try to stir them out.
Paint that passes these steps is as good as new. You can use it with the peace of mind that the paint job will look as good as one with brand-new paint.
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