Swirl-Free Sanding Techniques
Tips from the Dynabrade website
- Always START the sander ON the surface, and STOP the sander OFF the surface.
- When sanding keep the sander, and pad FLAT on the surface.
Important: Do not exert heavy downward force on the sander. Apply enough downward force to keep the back-up pad and abrasive flat on the surface allowing the back-up pad to orbit freely over the surface.
- Follow a set pattern when sanding.
It is suggested to pass over the surface following a "North, South, East, West" pattern, overlapping each pass 1/4 the diameter of the back-up pad and abrasive. This insures that the previous scratches are removed and that a uniform finish is achieved. Two "patterns" per sanding step are recommended.
- Frequently inspect abrasive for tears, folds, or build-up.
When changing abrasive to proceed to the next sanding step, first inspect the condition of the abrasive that is on the sander. If any defects are noticed in that abrasive, remove it and install another piece of the same grain and sand the work surface again before proceeding on to the next sanding step.
- Always clear away sanding dust and abrasive debris before progressing to the next sanding step with a finer "grit" abrasive.
Swirl Free Check List:
The pad must be flat and smooth, without any defects. Check if they are using a Dynabrade back-up pad that is "weight-mated" to the sander. Using another pad can make the sander vibrate excessively and lead to an unacceptable finish.
- Use quality abrasives.
Abrasive that has an additive to help prevent loading of the sanding disc will provide a superior finish than abrasive that has no additive. When
sanding particularly sensitive surfaces such as Corian® and other acrylic solid surface it is best to use a film backed abrasive sanding disc. Film backing forces the abrasive to lie flat on the surface. The grain is then presented to the sanding surface in a very uniform manner.
Original article from Dynabrade website