Scoop coaters are used for coating screens with emulsion in order to expose the screen to UV light with your film positive to create the stencil. When coating screens manually it is often difficult to achieve a smooth uniform surface with consistent thickness. To ensure complete coverage, filling in all of the mesh openings, you will want to use a multiple pass method with 2 passes being the minimum. Scoop coaters come with a thin, sharp edge and a duller, round edge. The thin, sharp edge will leave less emulsion in the mesh where the round edge will leave more emulsion in the mesh.
Tips for coating screen with emulsion:
- Only coat your screens under red or yellow safe light conditions.
- Mix your emulsion well before dispensing it into your scoop coater.
- A scoop coater should be clean and its edges free of dents and nicks. A smooth edge is best.
- Make sure the scoop coater is well filled. You don’t want to run out of emulsion halfway up the screen.
- Once the scoop coater is filled, the emulsion should be applied immediately. Emulsion left sitting in the open is a target for dust and debris.
- In low humidity environments, an open container of emulsion can begin to form a skin quickly, so keep your emulsion in an air tight container until you need it and after you apply it wash out your scoop coater right away.
- Coat the substrate side of the screen first. Begin your coating pass at the bottom of the screen. Firmly support your screen as you press the edge of the scoop coater against the mesh. Move slowly up the screen and slow down to a stop near the top. Twist the scoop coater upwards and off of the mesh. Flip the screen quickly and repeat on the ink well side.
- Be sure your emulsion coated screens are fully dry. If there is any amount of moisture in the emulsion during exposure, it can be a problem for stencil making and the emulsion may not work properly.
- The more emulsion on the mesh means you will need more exposure time. Lower mesh counts naturally hold more emulsion while higher mesh counts hold less emulsion.