Chatter Marks

Definition and Characteristics

Chatter marks, which are repetitive, parallel indentations or scratches on the sanded floor surface, exhibit certain characteristics. They maintain a consistent width and depth across the affected area, ranging from shallow scratches to deeper indentations. Notably, chatter marks are narrower and more closely spaced compared to waver marks. Chatter marks are often visible on the floor when light is directed onto its surface, appearing at intervals ranging from 5 to 20 mm apart. When you run your fingers across the sanded floor, you can often feel a consistent texture or ridges that follow the wavy pattern of chatter marks. Visually, chatter marks have a uniform and regular appearance, and they frequently cross the grain lines of the wood in a parallel fashion.

Causes of Chatter Marks

• Machine Issues: Chatter marks can occur due to problems with the floor sanding machine, such as an imbalance or malfunction. These issues can lead to uneven pressure distribution during sanding. Imbalances may arise from worn-out components or insufficient cleaning of the machine, which affects its smooth operation.

• Sanding Belt Grit: Another factor contributing to chatter marks is the use of an inappropriate or worn-out sanding belt with an excessively coarse grit. When a rough grit is used, it can result in deep gouges and irregularities on the floor surface, leading to the formation of chatter marks.

Waver Marks

Definition and Characteristics

Waver marks, also referred to as wave-like scratches, manifest as irregular indentations or scratches on the sanded floor. Unlike chatter marks, they lack a distinct pattern and can appear more random or irregular in terms of spacing and direction. Waver marks typically exhibit a spacing of approximately 25 to 150 mm between each occurrence. Waver marks exhibit variations in width and depth, resulting in a less uniform appearance. When touched, they may feel more uneven or irregular, displaying variations in both depth and texture. Visually, waver marks tend to appear sporadic and random, while also following the natural irregularities of the wood grain, deviating from a consistent pattern.

Causes of Waver Marks

• Debris on the Wheels: When debris such as dust, dirt, or small particles accumulate on the wheels of the drum or belt sander, it can interfere with the sanding process. As the machine moves along the floor, the debris can create irregularities in the sanding pattern, resulting in ripples on the surface. These ripples can appear as wavy marks on the floor, spaced further apart than chatter marks.

• Floor Unevenness: Larger wave marks are often a consequence of floor unevenness. When the sanding machine is used on a floor that has significant variations in height or surface irregularities, these imperfections can transfer through the wheels of the machine and affect the sanding process. As a result, the floor will exhibit larger, more pronounced wave marks.