Paint Storage Best Practices

Technical bulletin from Dunn-Edwards, the manufacturer of the paints sold at PaintPro.

When storing paints before or after a project, it is important to consider the temperature at which the product is stored. When temperatures are too hot or too cold, a product's shelf life can be shortened. For example, water-based paints stored below freezing (0 °C / 32 °F) can gel, especially after numerous freeze/thaw cycles. On the other hand, temperatures above 43 °C (110 °F) can cause paint to form skins on the top layer, create settling, and ultimately cause the paint to gel over time. Below are some precautionary measures to make sure your paint is not stored in conditions that could cause problems with the product.

Shelf stability in water-based paints

Latex paint consists of dispersed pigment and resin, along with some additives and liquid, which is mainly water. While the paint is in its liquid state, the particles of pigment and resin are distributed and spaced out. During storage, especially when exposed to extreme cold or heat, the stability of the paint system can be stressed. This stress can change the paint in the following ways:

  • Increased or decreased viscosity (the paint gets thinner or thicker)
  • Skinning or seeding of the paint
  • Syneresis / phase separation (a layer of semi-clear liquid on top of the paint with thicker paint material beneath)
  • Settling of pigments (soft or hard packing of pigments dropping out of the system, similar to how sand settles in a glass of water). With soft settling, the pigment can usually be stirred or shaken back in. With hard settling it cannot, and the result is bad paint that differs in gloss, viscosity and performance.

Coatings with reactive pigments

Storing at moderate temperatures is especially important for coatings that contain reactive pigments. Many high-performance water-based coatings for specific uses, such as light industrial, direct-to-metal, specialty primers, and topcoats for corrosion resistance or stain blocking, contain reactive pigments. They give extra protection and performance, but are much harder to stabilize than the pigments used in traditional architectural paints.

The Dunn-Edwards products in this category are listed below in alphabetical order by product code. Take extra care when storing them.

  1. ARISTOSHIELD® Eggshell (ASHL30), Low Sheen (ASHL40), Semi-Gloss (ASHL50), High Gloss (ASHL70)
  2. BLOC-RUST® Premium (BRPR00)
  3. ENDURA-COAT® Eggshell (ENCT30), Semi-Gloss (ENCT50)
  4. ENDURAPRIME® Metal Primer (ENPR00)
  5. EZ-PRIME® Wood Primer (EZPR00)
  6. ULTRASHIELD® Galvanized Metal Primer (ULGM00)

Additional precautions

  • Check the weather forecast. Find out the weather for the days you will paint and keep paint on the job site. If the temperature will rise above 43 °C (110 °F) or fall below freezing (0 °C / 32 °F), take special measures so the product is not kept at these temperatures for more than 24 hours.
  • Know your storage area. If you keep leftover paint for later use, check the temperature of the storage area and make sure it will not rise above 43 °C (110 °F) or fall below 0 °C (32 °F) for extended periods.

Download

Technical bulletin “Paint Storage Best Practices” (PDF, English)

Questions about storing paint? Visit us at Sayat-Nova 35, Yerevan, or call +374 11 203011.