How do you know when it's dry enough to spray on the oil?

Just cleaned my air filter (proper cleaner) and washed it through, shook out the excess water, dried it gently with a clean cloth and stood it in front of a fan to help dry it, but it didn't feel wet then and still no signs of dampness after an hopur ....so does anyone know how tell when it's dry and ready for oiling

you should put it in the hot press cupboard overnight as water embedded in the filter cotton will not have had a chance to evaporate after only a few hours. oiling the cotton before all water has left can lead to the oil not sticking to the cotton, and therefore a re-oil is needed very soon.

I usually leave mine for about 45 mins - 1 hour near a radiator. I then dab any excess water off with kitchen paper before applying the oil. Never had any problems with this technique yet

Reminds me, mine's probably due another clean now

Chris