Polishing Is Subtraction Not Addition
Every grade in a finishing sequence exists to remove the scratches left by the grade before it. Nothing in the sequence adds shine; the shine is what is left when the scratches are gone.
This is why skipping a grade cannot be recovered later. A fine wheel does not remove coarse scratches; it polishes the surface around them.
The Sequence
Gross reduction with a grinder or coarse bur. Shaping with mounted points, working down through the grits without skipping. Smoothing with rubber or silicone polishers. Final shine with a brush or buff and compound.
At each stage, inspect under good light before moving on. Moving on early is the most common error at a finishing bench.
Clean Between Grades
This is the habit that fixes most finishing problems. A single coarse particle carried on the work into a fine wheel will scratch the surface the fine wheel is supposed to be perfecting. Rinse or wipe between grades.
Dedicate Brushes to Compounds
A brush loaded with two compounds delivers neither cleanly. Mark brushes by compound and keep them separate. They are inexpensive and the separation pays for itself immediately.
Heat Is the Enemy of Acrylic
Acrylic distorts with heat. Pressing harder to finish faster generates heat, distorts the base and produces a denture that no longer fits. Let the abrasive cut at its own rate.
