Grinding and polishing — the road to the right finish
From coarse grain to mirror-bright surface
A forged soldered or turned item is rarely finished when the shape is there. The surface bears marks from hammer file and tool and it is the grinder's and polisher's job to bring it to the desired finish — whether mirror-bright matt satin or brushed. Iron and metal grinding is an independent specialisation precisely because finish is a discipline in itself requiring system patience and control over dust and heat.
§Stepwise grinding: grain becomes finer
Grinding proceeds in steps with increasingly finer grinding grit. One starts coarse to remove deep scratches, dents and tool marks, and works through finer and finer grit. The basic rule is that each step must remove the scratches from the previous one before moving on — if one skips a step, the coarse scratches remain under the polishing and only become visible at the end when it is too late. The sanding direction is often crossed between steps so you can see when the old pattern is gone.
| Step | Purpose |
|---|---|
| Rough grinding | Removes dents tool marks and deep scratches |
| Intermediate grinding | Levels and prepares the surface |
| Fine grinding | Removes the last visible scratches |
| Pre-polishing | Brings shine with cutting polish |
| High-gloss polishing | Spejlblank finish med blødt polermiddel |
§Polishing with pads and paste
Polishing is typically performed with rotating fabric or felt discs with applied polishing paste in decreasing coarseness. A cutting (coarser) paste is used first to remove grinding patterns and bring out the shine; a softer paste is used last for high gloss. The disc and paste should be matched to the metal — brass, copper and stainless steel are not polished with the same means. Finally, the part is washed free of paste residue.
§Matte satin and brushed finish
Not everything should be mirror-polished. A satinised or brushed surface hides fingerprints and minor scratches and is often desired on utensils. It is produced with abrasive fleece, brush or a fine sanding wheel, which lays a uniform, directional pattern on the surface. A matt finish can also be achieved by glass blasting or chemically. The choice of finish is both aesthetic and practical: a polished surface is beautiful but shows every fingerprint.
Faldgruber ved finish
- 01Skipping a grinding step → coarse scratches appear during polishing
- 02For coarse polishing compound at the end → matte blurred surface
- 03Too much pressure → heat discolouration and wear of edges
- 04Mixed paste and disc between metals → contamination in the finish
- 05Inadequate washing → dried pasta residue in corners and joints
“The polishing reveals everything you skipped — finish begins at coarse grinding.”