Interfacer

An interface pad is a soft, cushioned pad that is placed between the sanding disc and the sander's backing pad. The primary purpose of using an interface pad for sanding is to provide a softer and more flexible surface for sanding, which helps to reduce the risk of damage or uneven sanding.

Avoid scratches and marks

When using a sander without an interface pad, the sanding disc is directly in contact with the backing pad, which can cause the sander to leave swirl marks, scratches, or uneven sanding patterns. This is especially true when sanding uneven or curved surfaces.

Distribute pressure 

The interface pad helps to distribute the sanding pressure evenly across the surface being sanded, reducing the risk of damage and ensuring a more consistent sanding pattern. The pad's soft, flexible surface also conforms to the contours of the surface being sanded, making it easier to sand irregular or curved surfaces.

Improve quality

Overall, using an interface pad for sanding can improve the quality and consistency of the sanding job, and also help to extend the life of the sanding disc and the sander's backing pad.