IronBarc, just use a sock and then some womens stocking, stip them over the filter ...u can go 2 layers of stocking if needed, My filters stay really clean, any bigger chips seem to slide of the slippery surface of the stocking and with the super fine material it catches any fines before they reach the main filter, and on Big bore saws, they suck huge air ...so a air filter oil is a good idea, but if the main filter is oiled and not wrapped in a sock & stocking the fines and chips will stick to it, ....sock and stocking act like a pre-filter, keeping the main filter clean ....works a treat on my saws !