I used an air filter from a tractor, 275 Massey to be exact. Hole size is about 1/8th or lil bigger. Outer screen tube is about 4", inner screen tube is 2.5" or so. Soak the paper element with gasoline & lite 'er up!
I think the filter's length was 18", you could cut out slots to then wire wrap your larger screening material onto as well near then end for another size seperation.