How to Store Powder Coating - The Ultimate Guide
One of the many benefits of powder coating is you can continue to reuse the powder out of the box after it has been opened, this is in contrast to many liquid paints that tend to not be able to be left after being opened. While being able to store powder coating is a huge benefit that powder coating offers, proper storage is critical to ensure you are able to properly make use of the powder when you want to in the future. Failure to consider how to store powder effectively can create issues with powder clumping together, which can make it difficult or even impossible to apply. Knowing the downside of improperly storing powder coating, we are going to cover how you should store powder coating to ensure issues are prevented.
Powder Coating Storage Factor 1 - Temperature
Powder coatings prefer moderate temperatures for storage. In particular powder coatings tend to do best when the temperature of the storage area is below 80 degrees Fahrenheit. Heat is one of the common causes of lumps in powder, which are often able to be addressed by properly sieving the powder prior to use. However, it is always best to prevent lumps where possible so having a storage area below 80 degrees is ideal, this means using an air conditioned area ideally.
Powder Coating Storage Factor 2 - Humidity
Even more problematic to powder coating storage is humidity, which can cause powder coating to stick together. If your powder coating sticks together, it will not fluidize as well which can create a poor orange peel in your final powder coating finish. Ideally powder coating should be stored between 50% and 65% relative humidity. To ensure your storage area’s humidity is properly controlled you can always use a humidity gauge that also tracks temperature to verify your room has the proper conditions for powder coating storage.
Powder Coating Storage Factor 3 - Sunlight & Potential Contamination
Beyond temperature and humidity the other two pertinent factors to consider when storing powder coating is sunlight and potential contaminants. Sunlight can cause powder to clump creating issues with fluidizing the powder coating. Additionally outside contaminants can cause issues effectively spraying the powder, lumps, and negative effects to your powder coating finish. To avoid problems like these due to contamination and sunlight your powder coating should be sealed and out of direct sunlight when not in use. This can be accomplished by leaving the powder in the box it came in or by sealing a powder hopper if your using a hopper fed powder system.
Practical Steps to Storing Powder Coating
- Powder coating lines should purge all powder that is left where possible as a step to prepare for the end of the day
- If powder coating will be left in a hopper, ensure you have an air tight seal and the storage area temperature and humidity is properly controlled
- Keep the storage area between 50 - 65% relative humidity and below 80 degrees farenheit
- Most powder coatings are ok to reuse for up to one year after initially opening if properly stored, your product data sheet for your powder will definitively state safe storage time for your powder