To make polycarbonate clear again, one of the most effective methods is flame polishing. However, before proceeding with flame polishing, it is important to do some preliminary work to prepare the surface of the polycarbonate.
1. Start by examining the polycarbonate surface for any saw stroke or milling marks. These marks can make the surface appear cloudy or opaque. Identifying the areas that need attention will help you focus your efforts on those specific areas.
2. Begin the process by using sandpaper to smoothen the surface. Start with a coarse grit sandpaper, such as 120 grit, and gradually move to finer grits, such as 220 and 400. This will help to remove the roughness and any visible marks on the surface. Remember to sand in a consistent direction to achieve a uniform finish.
3. Wet sanding can also be used to further improve the surface quality. Wet the sandpaper and continue sanding in the same consistent direction. The water helps to lubricate the surface, reducing friction and preventing the sandpaper from clogging up with debris.
4. After sanding, thoroughly clean the surface to remove any dust or debris. A lint-free cloth or microfiber cloth can be used for this purpose. Ensure that the surface is completely dry before proceeding to flame polishing.
5. Flame polishing is the key step in achieving a crystal-clear finish on polycarbonate. This method involves using a high-temperature flame source, such as a propane torch, to heat the surface of the polycarbonate. Hold the flame a few inches away from the surface and move it in a circular motion to evenly distribute the heat.
6. As the surface heats up, it will start to melt and become glossy. Be cautious not to overheat the surface, as excessive heat can cause the polycarbonate to warp or deform. Take breaks in between and allow the surface to cool down before continuing.
7. Continue flame polishing until the entire surface is smooth and clear. Pay close attention to any remaining marks or imperfections and focus the flame on those areas for a little longer if needed.
8. Once the flame polishing is complete, allow the polycarbonate to cool down naturally. Avoid sudden temperature changes or exposure to cold water, as this can cause stress on the material and potentially lead to cracking or damage.
9. After cooling, inspect the surface for any remaining imperfections. If necessary, repeat the flame polishing process or perform additional sanding to further refine the surface.
10. clean the surface once again to remove any residue or debris from the flame polishing process. Use a mild soap or detergent and a soft cloth to gently clean the surface, ensuring that it remains scratch-free.
By following these steps, you can effectively remove saw stroke or milling marks from polycarbonate and restore its clarity. However, it is important to note that flame polishing may not be suitable for all types of polycarbonate, so it is advisable to test the method on a small, inconspicuous area before proceeding with the entire surface.