Polishing gelcoat is a kind of finest sanding

When polishing surfaces made of gelcoat, the initial condition must be taken into account and changed if necessary. For the polishing process itself the thoroughness and patience are decisive for the success. The basic principle is polishing a very fine grit and / or abrasive paste. Time is the deciding factor in any case.

Basic cleaning for preparation

Before polishing, an inventory of the condition of the surface must be made. Depending on the condition, the intensity of the basic cleaning must be determined. For lighter soiling and / or weathering, it is usually sufficient to spray a strong alkaline cleaner to clean the gelcoat. After a short reaction time, it is rinsed off.

If, after this treatment, the surface does not shine cleanly and shadowless, a preliminary sanding of the gelcoat is unavoidable. The result and the quality of the gloss after polishing depend directly on it. For "grinding" cleaning, there are several sanding polishes as aids:

  • Abrasive paste or liquid with grain additives of different sizes and quantities
  • chalk
  • polishing slate
  • stannic oxide
  • Polierrotkuchen

The processing of the gel coat with one of these polishes is only preliminary and the actual polishing is a separate following process.

Polishing tools and tools

The polishing of gelcoat can be done both by hand and with a polishing machine. Surfaces larger than half a square meter should be machined. The effort and time spent on larger surfaces is immense and often leads to an unsatisfactory result.

Polishing machines have so-called plates on which the abrasive is clamped. Usually it is polished at a rate of one thousand revolutions per minute. As abrasive sheepskin or polishing sponges are used. Lamb and plastic skins are unsuitable.

How to polish gelcoat

  • Strong alkaline detergent
  • abrasive polish
  • Abrasive 1000 and 3000 grit
  • water
  • bucket
  • polishing paste
  • Grinder (no angle grinder) with 1000
  • Revolutions / minute
  • spray bottle
  • Two microfiber flaps

1. Preparations

During polishing, the abrasive and gelcoat must always be kept moist and clean. Put lukewarm water in a spray bottle and fill a container or bucket of cleaning water into which you add a few sharpeners of strong alkaline detergent. Have a moistened and dry microfiber cloth ready.

2. Apply polishing paste

Squeeze a pea-sized amount of polishing paste onto the clamped dry abrasive. When the grinder is off, roughly spread the paste over approximately one-quarter square meter.

3. Start polishing

Moisten the surface and start the grinding machine at the lowest speed, normally 1000 U / m. Begin with evenly pressed sanding pad in circular motions further and finer to distribute the polish. Keep the surface permanently moist.

4. Wipe and final polish

When wiping off the abrasive, wipe off first with the damp and then with the dry microfiber cloth. Change the plate tension after every polishing process and wash out the used ones. Let it dry before reuse. The last polishing pass is on a dry surface.

Tips & Tricks

The slower the sanding pad rotates and the longer you work the surface, the better the polishing result becomes.

Video Board: Must Watch BEFORE Wetsanding Paint!