Water Level Controls and Devices. A water column is used on a steam boiler to reduce the turbulence and fluctuation of the water level so the gage glass can provide a steady, accurate water level reading. The use of a water column is not mandatory.
Preparation. Verify the paint is completely dry. Never use varnish to seal acrylic paint if it is even slightly wet. Dust the surface of the dry paint gently with a clean cotton rag or paper towel. Rinse a jar or cup with water to remove any dust particles. Read the label on your varnish to find the correct water-to-varnish ratio. Mix the varnish with water in the jar or cup.
Tips. 1  It may be possible to spray paint your plastic item with the plastic spray paint used as a primer, and then use regular exterior acrylic latex paint as a top coat. 2  This would give you a bigger selection of colors. 3  The plastic spray paint would allow the other paint to adhere to the surface of the plastic.. Tape off the plastic (optional). If you donât want to paint the entire object, you can choose to tape some of it off. Use regular painters tape to mark off the sections you donât want to be painted; the tape should be removed when youâre completely done painting while the paint is still wet.