All purpose joint compound drying time
All Purpose Joint Compound Drying Time (also known as pre-mixed joint compound) is typically around 24 hours per coat:
The first coat of all-purpose joint compound usually takes 24-48 hours to fully dry, depending on factors like temperature, humidity, and application thickness.
Subsequent coats of all-purpose joint compound can dry in 12-24 hours, as long as the previous coat has dried thoroughly.
Temperature and humidity:
Higher humidity slows down the evaporation of water in the joint compound, resulting in longer drying times.
Temperature has a significant impact on the drying time of joint compounds:
Under ideal conditions of 70°F temperature and 70% humidity, all-purpose joint compound typically takes about 24 hours to dry per coat.
Higher temperatures will speed up drying time. Ideal drying temperatures are between 70-75°F.
Lower temperatures below 70°F will slow drying. At 55°F with high humidity, drying time can be 4 times longer compared to ideal conditions.
Applying joint compound when temperatures are below 50°F can lead to a variety of problems like bond failure, delayed shrinkage, nail popping, and board sagging.
Thickness of application:
the thicker the application of joint compound, the longer it will take to fully dry. Applying joint compound in thin, even coats is recommended to minimize drying time. Rushing through thicker applications in unfavorable environmental conditions can significantly prolong the drying process and lead to finishing problems.
Ventilation and air movement:
controlling humidity levels through proper ventilation and air circulation is far more important than just controlling temperature when it comes to ensuring timely drying of joint compound during construction. Failing to manage the environment can significantly delay finishing schedules.
Type of joint compound:
Setting-type joint compounds generally dry faster than pre-mixed or lightweight joint compounds. Pre-mixed joint compound typically takes around 24 hours to dry per coat under normal conditions of 70°F temperature and 70% humidity. Higher humidity and/or lower temperatures will slow the drying time.
Setting-type joint compound, on the other hand, has a much faster drying time. The initial setting usually occurs within 20 to 45 minutes, and you can apply subsequent coats on the same day. However, it’s still best to wait 24 hours before sanding and painting.
The faster drying time of setting-type compound is one of its main advantages over pre-mixed. It allows you to complete projects more quickly, as you don’t have to wait as long between coats. However, setting-type compound can be more difficult to sand smooth compared to pre-mixed.
In summary, pre-mixed joint compound takes around 24 hours to dry per coat, while setting-type compound sets in 20-45 minutes, allowing for faster project completion, though it may require more effort to achieve a smooth finish.
Environmental changes during the project:
As the job environment becomes more humid over time, it can significantly increase the drying time for subsequent coats of joint compound.
To summarize, under normal conditions, you should plan for about 24 hours of drying time between coats when using all-purpose joint compound. Adjusting factors like temperature, humidity, and application thickness can help speed up the drying process if needed.
Speed up all purpose joint compound drying time
Here are the key tips to speed up all purpose joint compound drying time:
* Reduce the humidity in the space by using a dehumidifier. Humidity is one of the biggest factors in drying time.
* Increase ventilation and air circulation by opening windows (if not humid outside) and using fans.
* Raise the temperature in the room by using space heaters. Even a few degrees higher can help speed up drying.
* Consider using a “hot mud” or quick-setting joint compound, which can dry in as little as 12-20 minutes instead of 24 hours for regular compound.
* Apply the joint compound in thinner coats, as thicker applications take longer to fully dry.
The key is to reduce humidity, increase air flow and temperature in the work area. Using a specialized quick-setting compound can also significantly speed up the drying time, but requires more skill to apply properly. Focus on creating the optimal drying conditions rather than trying to chemically accelerate a standard joint compound.
