A one-part, ready-to-use internal plaster bonding agent with added aggregate to provide a key prior to plastering on smooth surfaces. This bonding agent is suitable for smooth surfaces and contains sand/aggregate to provide a plaster key. It is a ready-to-use, one-coat application, perfect for use on smooth substrates. The product is pigmented yellow to identify treated areas and has a phthalate-free formulation. PLASTERERS PREGRIT should be used as a primer/bonding aid prior to plastering on surfaces such as concrete, plaster, and difficult, low, or non-porous substrates. It is for internal use only and not suitable for external applications.