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.
Meanwhile, acrylic paint is very elastic, which prevents cracking from occurring. Acrylic paint's binder is acrylic polymer emulsion â as this binder dries, the paint remains flexible. Another difference between oil and acrylic paints is the versatility offered by acrylic paints. Acrylics are very useful in mixed media, allowing the use of pastel (oil & chalk), charcoal and pen (among others) on top of the dried acrylic painted surface.