When I first started doing pour acrylics, I was always running into the problem of finding places to put my drying paintings. I was having so much fun painting that I was creating new pieces faster than the previous works were taking to dry.
Currently I paint on my kitchen table, and my paintings dry in our “multi-purpose room” aka. junk room. I only have about three square feet of floor space to use so I have to very careful how often I paint in order to have space for the paintings to try. That being said, drying process for my acrylic pours is very important to the amount of painting that I can create.
How long do acrylic pours take to dry? Most acrylic pour paintings take between 24 and 72 hours to dry and between 7 and 14 days to cure. Heat, humidity, airflow, materials used, painting surface, and other factors can both positively and negatively affect your drying times.
With so many important components to the drying process, it is important that you understand each. Whether you want to able to paint more often, sell your work, or simply display it at home, the drying process is an critical piece to a complete painting.
The Steps Acrylic Paints Take When Drying
When acrylic paint dries, whether poured or applied directly to a surface, they tend the follow a pattern of sorts. The steps in this pattern are meaningful to understand so that you doing unintentionally cause harm to your pouring projects.
Below is a quick summary of an amazingly detailed and technical article written by Mike Townsend from Golden Artist Colors about the drying process of Acrylics and Gels. If you want to dive into the nitty-gritty details, please review his article which can be found here.
One vitally important part of the process is the times each of these steps take for pour applications is much higher compared to straight painting application . The mediums used to create the fluid nature of acrylic pouring paint extends the first few steps of the drying process considerably.
Step 1 – Wet Paint
Paint in this format is right out the container. The paint is malleable and is easily moved around the painting surface. When exposed to the air, the water and solvents, or volatiles, rapidly start leave the paint. Note: The loss of these volatiles is how paint “dries”. For pour acrylics this stage can last anywhere from a few hours to a few days.
Step 2 – Skinned Over
Once the quickly escaping volatiles have completed their exit, the paint begins to form a skin on the outside of the painting. This areas with the most exposed surface areas like corners are going to see the skins form faster while the interior portions take longer the form. This will generally be evident on the edges after four to eight hours of dry time for an acrylic pour.
Step 3 – Touch Dry
For the Touch Dry stage, the skin on the painting has developed enough that touching the surface of the paint does not wrinkle or tear. Paint underneath this layer may still not be entirely dry yet. This is normally seen to happen on the outside of a painting first after the first 24 hours.
Step 4 – Dry to Handle/Solid State
At this stage, the paint on the painting surface appears to be dry. The skin mentioned in steps 2 and 3 is now thicker and harder. This is really the danger zone step where most artists believe their paint is dry and ready final preparation.
The paint has not had enough time to dry all the way through, and the bond between the painting surface and the paint is not fully formed. Excessive handing, rolling, or adding additional layers of sealers (like varnish, or resin) could cause the paint to pull away from the painting surface.
Step 5 Cured/Coalesced
The last step of the drying process for acrylic paints is the cured stage. The volatile water and solvents have almost completely evaporated. The acrylic paint molecules are all closely packed now (this is what causes the plastic skin like effect when drying). The painting should be ready for additional layers or for finishing at this point.
An acrylic pour painting can continue to “cure” for weeks after the 5 steps mentioned above, but the amount of volatile leaving the painting is minuscule compared to the first few days of the drying process.
As mentioned above, paint does not dry uniformly. The areas exposed to the air the most will tend to dry faster. On a canvas, for example, the paint will dry on the outside edges the fastest. The center of the painting might still be in step 2 while the outside of the painting is now in step 3. This is called zonal drying. For acrylic paint pouring projects, zonal drying will continue until the whole painting is the cured/coalesced stage.
How the Environment Affects Drying Times of Acrylic Pours?
The drying process can be affected by a number of different environmental concerns including temperature, humidity, and airflow. The water and solvents in the paint evaporate at different rates based on the combination of these variables.
According to Golden Artist colors, the ideal temperatures for paints to dry are between “65-75° F (18-24°C) with Relative Humidity above 50%”. Paint will not dry unless the temperatures are above ~49° F, and the water in the paint will freeze at just under 32° F. Temperatures above 75° F can cause the surface of the painting to dry much faster than the underlying paint layers which can causing cracking and crazing.
Humidity refers the amount of water in the air. The drying process of acrylic paints, especially acrylic paints mixed with a liquid-like medium, require that water and solvents dissipates out of the paint and into the air.
If the air is too humid outside of the paint, the water molecules will not evaporate as quickly as because there is less room for additional water in the air. In contrast, when the humidity is very low, the drying process will speed up as there is plenty of room in the air for additional water molecules.
The air flowing around a drying pour can cause the painting to dry out faster than it would with a more calm area. Essentially, this becomes of function of changing humidity.
Blowing on a surface causes the air around that surface to change. In the case of the drying painting, the air right near the surface is accumulating more water and solvents from evaporation. It takes time for these evaporated gases to move away from the painting as it equalizes over a larger area.
As was mentioned above, the more humid the air is around painting is the less quickly evaporation occurs. When an external force moves the air around the painting, that humid air is quickly replaced by less humid air, allowing the evaporation process to move more rapidly.
The evaporation process will happen more quickly at higher elevations because of the additional air pressure. Air pressure makes molecules move faster.
In the case of paint drying, the quicker molecules move inside your paint, the quicker they can find ways to escape increasing the speed at which evaporation happens. At lower elevations this process will slow down.
While changing elevation to manipulate drying times is impractical, if you move from one elevation to another, your observed drying times will most likely change.
The surface on which you paint can have an affect on how long your painting takes to dry. Finished hard surfaces, like wood panels, or surfaces that are well sealed do not have as much ability to absorb some of the water and solvents from the paint. This materials won’t change the drying time very much at all.
Painting surfaces such as canvas panels, stretch canvas, paper, and raw wood that can absorb more of the water and solvents will cause the painting to dry faster.
In the case of the hard, finished, or sealed surfaces, the paint can really only evaporate through the top and sides of a painting. With the more porous surfaces, like canvases, the water and solvents can leave though the painting surface material in addition to the top and sides of the painting thus speeding up drying times.
Slowing Down Dry Times
On occasion, your pour may be drying too fast which can cause crazing or cracking of the paint. Drying times can be slowed by adjusting the environmental variables or adding additional materials to the paint.
- Reduce the temperature of the drying area while keeping it in the recommended 65-75° F can slow the drying process.
- Dry your paintings in a room with a humidifier or difuser to increase the humidity in the room. If you hang dry clothing, doing so in the same room and you paintings can help raise the humidity. Be careful not to increase the humidity beyond ~75%.
- Reduce the airflow in the room. Close vents, windows, and doors to keep the movement of air to a minimum.
- Tent your painting – Tenting refers to building a tent, usually out of painters plastic or plastic sheeting. Ensure this plastic cannot come in contact with the painting and that there is little or no open ventilation into the tent. This helps keep the humidity higher under the tenting and reduces airflow as they paint dries.
- Add a retarder to your pouring mixture. A retarded is an additive that slows down the drying time of paints. Many are glycerin-based additives which slow down how fast water and solvents move through a mixture thus “retarding” or slowing down the evaporation process.
- Leave the paint slightly thicker on the painting surface for acrylic pours. This will increase the amount of time it takes for the paint to dry. It is not recommend to leave a layer of more than an 1/8″ and preferably closer to a 1/16″ on the painting surface. Thick application of pour paints are more prone to cracking and crazing.
- Use a finished hard painting surface or seal the surface before painting.
Speeding Up Dry Times
In some cases, it may also be helpful to speed up the drying time on your painting. As with slowing, speeding up requires that you change the environment in which the paint is drying or adding something to quicken the drying process.
- Increase the temperature of the drying area while keeping it in the recommended 65-75° F can help speed the drying process.
- Dry your paintings in a room with less humidity. Rooms with plans will be more humid that those without. Cooking and food preparation can also add additional moisture into the air. Showers, air drying clothes, and clothes washing machines can also add unwanted moisture into the air.
- Open the window slightly, ensure your heating or air conditioning vents are open, or add a fan to increase the airflow in the room. Be careful of dust and other airborne particles as they can stick to wet paint.
- Use a matte paint medium in place of a gel or gloss medium will also decrease the drying time of a painting.
- Allow less paint to sit on the painting surface. 1/16″ is a good thickness of paint that will cover well when dried, although this is subject to the type and color of paint and medium used. Stretched canvas tends to hold more paint in the center where there is more give in the canvas. Pull this excess paint to the sides or off the canvas to help decrease your drying times.
- Use a more porous unsealing painting surface like canvas, raw wood, cloth, or paper.
There are many factors that can affect the time it takes for your painting to dry. Humidity, temperature, additives, airflow, painting surface, and elevation are some of the more important variable to consider.
The final product of a pairing comes after the paint is dried. By understanding how the drying process works, you have the power to make the best possible decisions to ensure the success of your artistic efforts.
Does the size of the painting surface or canvas affect dry times? The size of a canvas or other painting surface has little affect on dry times for acrylic pours. A 1/16″ layer of paint on a 6″ X 6″ canvas will dry in almost the same time as a 1/16″ layer of paint on a 16″ X 20″ canvas. The factors detailed above will have more do do with the drying times than anything else.
Does the quality of the acrylic paint affect drying times? Acrylic paints are made from very similar materials and thus will dry at the same basic rate. The makeup of some color pigment may affect how slowly or quickly a paint dries although these different will tend to be almost imperceptible in most cases.
When can I seal my pour acrylic painting? Do not seal your painting for a least 7 days and preferably waiting 14 or more days. Sealing your paintings before they have dried and cured properly could allow the paint to pull itself off of the painting surface because the adhesion process is not complete.