Call us now: 800.662.0336   |    Log In

DIAMOND POLISHING BASICS -
HOW TO ACHIEVE A SPI #1 or SPI #2 FINISH

  1. The first step with diamond polishing is to find an area in the shop that is clean and is away from other machining and polishing operations. Airborne dust and grit can greatly affect the final finish during the diamond polishing process. Make every effort to eliminate these conditions.
  2. Make sure all stoning marks are brought to a 600 or finer grit stone finish on the mold surface.
  3. Mold surface must be cleaned extremely well! All 600 or finer grit stone residue must be cleaned from the mold surface.
  4. Next use a rotary brush with Grade 30 or 15 diamond compound to remove stoning marks. Use a slow rotary speed and light pressure. If heavy pressure is used it can cause a surface condition called "Orange Peel". This can be caused by over-stressing the mold surface with excessive heat created by too much pressure and speed.
  5. When all stoning marks are removed, clean the mold surface. Cleaning is a very critical part of this polishing process. Extra care must be used to make sure all previous grade diamond compound is removed. It is recommended to use a very soft tissue to clean the surface. This will help eliminate unwanted scratches during the cleaning process.
  6. Next use a medium to hard felt bob with Grade 15 or 9 diamond compound to remove all brush marks from the previous polishing step.
  7. Again, clean the mold surface and be sure all the previous grade diamond compound is removed.
  8.  Next use a medium or soft felt bob with Grade 9 or 6 diamond compound.
  9. Again, clean the mold surface and be sure all the previous grade diamond compound is removed.
  10. Next use a soft felt bob with Grade 3 diamond compound to get the #2 finish.
  11. If you need a #1 finish, clean the mold surface and then use Grade 1 or finer diamond compound with a soft felt bob.