Rejuvenating old fuel, used degreasers and paint thinner

 
Be extremely careful when working with ignitable wastes. 
  • Work outdoors or provide adequate ventilation by opening windows and doors and/or turning on a room fan.
  • Stay away from potential ignition sources like pilot lights or sparks of any kind.  
  • Wear protective clothing such as chemical-resistant gloves, eye protection and long sleeves, and take care not to breathe any fumes.
 
Fuel 
  1. Carefully filter old fuels through two layers of lint-free cloth or coffee filters to remove contaminants like dirt, rust or “varnish.” 
  2. If needed, add an octane booster (available at auto supply stores or gas stations) to restore lost ignitability.  
  3. If the fuel is contaminated with small amounts of water, add a water dispersant (ethyl alcohol) or "dry gas" (isopropanol) (available at auto supply stores or gas stations) to break up the water so it doesn't enter the engine all at once.  
  4. If the fuel is contaminated with larger amounts of water, the water will sink to the bottom of the container.
  • Mechanically siphon the product floating above the water into an approved fuel container and rejuvenate it using the process above.
  • The residual water and fuel remaining in the original container will have to be stabilized for disposal.
  1. The rejuvenated fuel can be mixed with new product at a ratio of 1 part old to 5 parts new, then used as intended.  
  2. Two-stroke mixtures can be rejuvenated by filtering as above, adding about 1 quart of gasoline to each gallon of two-stroke mixture, then adding enough oil to bring the mixture up to the proper ratio.
  • A water dispersant or “dry gas” may be added to the rejuvenated mixture if needed.
 
Degreasers 
  1. Carefully filter used degreasers through two layers of lint-free cloth or coffee filters to remove contaminants.
  2. The cloth or coffee filters used to strain the degreaser should be laid out to dry outdoors in a well-ventilated area away from potential ignition sources, children and pets. The dried cloth or filters can be disposed of in the regular trash when dry.
 
Paint thinners 
  1. Pour the used thinner into a glass jar. Tightly seal the jar and label it with the type of product and a warning not to open the jar.
  2. Allow the paint solids to settle to the bottom of the container. Then carefully pour the clear thinner into another container for continued use. Make sure the new container is properly labeled.
  3. Dry the solids in the bottom of the first container by mixing them with an absorbent like clay-based cat litter. The dried solids can then be disposed of in the trash.