Some help please- screen exposing/ burning

Hello,

I’ve recently got into screen printing and could do with some help.

So I’m burning my graphics into the screens using film ofc... I’m struggling so I burn the screens take them straight to the wash out booth and I give it a spray with the power washer the graphic slowly comes out but when I’m doing it over and over the emulsions slowly coming off too.

I’m using a DIY exposure unit basic floodlight setup exposing my screens for 20 minutes.

Look forward to hearing from you all