Plenty of research to show that just adding wire mesh or wire wool to a catch can doesn't do the job properly either.
You ideally need a larger circular vessel with the air oil vapour going into the side and an internal baffle similar to an upside down cup inside with the exiting air coming out of the centre top.
This allows the air oil vapour to enter the vessel circulate and slow down and release the oil onto the outside surface of the inverted cup and side of the vessel. This will run down and collect in the bottom whilst the cleaner air can escape via the inside of the cup.
The mesh in the vortex recommended one will clog up and allow the air flowing through it to pick oil on its way through.
Most air oil seperators are too small to do the job properly, but may be better than nothing.
Paul
