Wire mesh filter elements should be treated when new and after each cleaning.  There are two methods for treating wire filter elements:

1. Oil treatment: Elements can be dipped in SAE 30-50 motor oil and drained thoroughly before using.
2. Oil-free Adhesive treatment: This product from Universal can be used to treat wire elements in applications which do not permit oil wetting of the elements, such as oil-free compressors.

81-0323 Oil-Free Adhesive from Universal

13 ounce aerosol spray can, Universal part number 81-0323

Universal oil free adhesive is an oil-free product developed for use on viscous impingement type filters. It is a substitute for oil for applications which do not permit oil wetting of the elements, such as oil-free compressors.

New filters* should be treated by spraying a thorough coat of the adhesive onto both sides of the filter element and allowing to dry about ten minutes before placing into service.  Instructions can be found on the cans.
*Universal type W-2 filters are treated at factory prior to shipment

Used filters must be cleaned and dried according to instructions prior to application of the adhesive.

Cleaning Wire Mesh Air Filter Elements
To clean a wire mesh element, wash in solvent or warm water and detergent in a container large enough for complete immersion of element. Rinse completely, drain, and then either air dry or use compressed air. After cleaning and drying, re-treat the element with oil free adhesive or oil as described above.

Time to change your filter element? A clean element should have a pressure drop of 1 to 3″ of water column (w.c.). Filter elements should be changed when the pressure drop exceeds 10-15″w.c. of pressure loss. You may want to clean or replace the filter depending on the power usage of your machine. Remember, excessive pressure drop will cost you horsepower ($$$) and can also cause excessive temperature rise on the blower causing blower failure, excessive horsepower absorbed by your drive (for instance v-belts) which may cause premature failure, and excessive horsepower on your motor causing overload and premature failure