GF is rather conservative regarding the life of our Milk paint. Water based products do not last forever, even when unopened. General Finishes products are best used within 1-2 years.
However, the life of the product may be extended with proper care and storage. If the can is in good condition, unopened and stored in correct temperatures, water based products can last 3-5 years. Avoid temperatures below 50°F/10°C or above 80°F/26°C and keep from freezing. Note, a can of paint that is 3 years old will not look like a can of paint that is 6 months to 1 year old. You will see stratification or separation, which is normal. Always stir thoroughly before using.
If your paint has a foul smell, the product is contaminated and is no longer in useable condition. Failure to reincorporate large, chunky lumps when stirring indicates the product has frozen and can no longer be used.
Please be mindful of the manner in which your paint is stored and how long it's been in storage. It is not a forever product.
Water-based finishes crystalize and form a skin due to evaporation when the air-tight seal on a can is broken at first use. The following best practices will increase the life of your product:
- Pry open sealed lids with a paint can opener by hooking under the lid's rolled edge. The use of a screwdriver can disfigure the rim and lid, impairing a complete seal.
- Keep lid closed while working. Pour what you will use into a bowl, paper cup, or plate, and close can lid as you work.
- Clean the chime of the can thoroughly with a paper towel before closing to create a complete seal. Paint in the chime can be minimized by using a pouring lid, such as Fitsall. Avoid wiping used brushes on the lid.
- Pound the lid in place using a rubber mallet to avoid distorting the chime or lid. Dents in the lid from direct contact with a hammer can impair a complete seal. Alternatively, place a flat piece of wood over can lid and firmly pound shut.
- Store in moderate temperatures. Avoid temperatures below 50°F/10°C or above100°F/38°C. Keep from freezing. Frozen and heat-damaged product cannot be revitalized. Temperature-controlled spaces, such as a basement, are ideal for storage. Do not store product in an attic, garage, in direct sunlight, or next to something warm like a water heater or furnace.
- Store can upside down to create a liquid seal, minimize evaporation and reduce the chance of crystallization. Decant remaining product from the can before stirring.
- Decant leftovers to a smaller container when the finish is almost used up. Alternative storage containers for water-based products are plastic FIFO bottles or glass bottles. Do not fill metal-lidded containers completely to prevent them from rusting.