PlasteringDevil float for undercoat plasters
Plasterers devil float is used to key the undercoat or backing plaster ready for final plastering or finishing
![Devil float for undercoat plasters Devil float for undercoat plasters](https://www.justgypsum.com/upload/05012018162628WOBNB.jpg)
A devil float, also known as hand float, contains nails that slightly stick out at one end and is used to roughen the surface of plaster to provide a key for the next coat. It can also be used to get rid of any bumps.
A devil float is used to help close in the surface of the backing plaster like thistle bonding coat, thistle hardwall or sand and cement render. This is commonly known as "rubbing up". It has screws projecting at the top corners to key the surface ready for the finish plaster.