Bonding Plaster: Bonding is an undercoat plaster. This means it is the first coat, or undercoat to be applied to a new (or to be patched) wall. … It is the most often used undercoat plaster these days, and can be applied to most masonry surfaces.

What is bonding plaster for?

Bonding Plaster: Bonding is an undercoat plaster. This means it is the first coat, or undercoat to be applied to a new (or to be patched) wall. … It is the most often used undercoat plaster these days, and can be applied to most masonry surfaces.

Does plaster need a bonding agent?

2 Answers. You shouldn’t need a bonding agent, for putting a base coat on a scratch coat, or a finish coat on a base. However you do need to make sure you scratched the scratch coat properly, and you do need to dampen an existing coat of plaster before you put on the new wet plaster.