Shop towels serve their purpose well by wiping off oil and grease, but eventually they become so dirty they are no longer effective. Washing these contaminants out is not as simple as tossing the towel in the wash and hoping for the best. In order to reuse shop towels and extend their lifespan, they must be properly cleaned. Cleaning techniques will work best on towels that have light to medium grease and oil buildup. They can be used on severely stained shop towels but the results may not be as effective.
Pre-soak the shop towels. Get a bucket of clean, warm water and put the shop towels in. Only add in four or five towels at a time, depending on the size of your bucket. A large 5-gallon bucket can hold up to six to seven shop towels.
Add baking soda into the water. The baking soda will help break up the grease and oil that has been ground into the towels. Use approximately 1/2 cup of baking soda per bucket. Let the shop towels soak in this mixture for one to two hours.
Dump the water out of the bucket in a safe spot. Since this water contains contaminants it should not be poured down the drain or into the ground. Pour this water into a barrel and set it aside.
Refill the bucket with water and add Goop or a comparable oil remover soap. Put the towels back in the water and allow them to soak for another hour. Dump this water out into your barrel again once they have soaked.
Rinse the towels. Any oil and grease should be removed from the shop towels at this point. If not, repeat steps 2 through 4 until the contaminants are removed. Once they are free of grease and oil they can be rinsed in the sink.
Air-dry the shop towels. Hang the towels up in an area with good airflow to let them dry properly. This should take approximately five to eight hours. They will likely be a little stiff but they should be clean and reusable.
Never wash or dry shop towels in a regular or commercial washing machine and dryer. These chemicals are flammable. In addition, washing machines drain either into the ground or the city sewer system and grease and oil will contaminate the water supply.