One cotton ball spread evenly sa output side (before you install the valve) and I covered it with a layer of jeans cloth to make sure di ito mahigop towards the valve. I never under estimate engine vacuum, napakalakas nito kaya dapat matibay ang filter sa output side.
Dalawang cotton balls naman sa intake side bago ilagay ang sponge filter. Just spread the cotton balls evenly flat to a uniform thickness to cover the area kung saan ito ilagay. The flattened cotton balls is a very cheap material yet very effective filter than any sponge or plastic screen. Since cotton is also an organic fiber, it does not interfere with what comes out of the device.
I added the taffeta (
Taffeta - Wikipedia, the free encyclopedia) cloth to cover the intake side para di malaglag ang filters and it also served as and additional outer filter for all incoming air. However, wala akong alam na mas effective na mechnism to keep the taffeta in place than to hold it around the opening with aluminum tape. Electrical tape does not work well, gagalaw ito overtime. I also noticed the advantage of using the taffeta cloth, dust can't easily get inside and can easily be removed from the taffeta cloth - madulas kasi ang taffeta cloth and if ever gustong ma renew, washable ito.
These materials like jeans cloth (cotton material and strongly woven), cotton balls (cheap and a houshold material), taffeta (also cheap and available in any textile stores, tightly woven) all can work together for a long term as almost maintenance free filters.
Should you add this as an improvement to the device, di gaano magastos at madaling gawin. Should a user add this as part of the enhancement, madaling mahanap ang mga ito lalo na kung malapit ka sa isang tailoring shop - basura na nila ang small cuts na pwedeng magamit sa device. hehe
Effective filtration on the output will make sure no large particle can get in the engine. Better filtration on the input side will make sure walang mag contaminate what's inside the device and allow it to perform better.