Working with a grinder.

 
 
  If you have work experience, I’ll give you a piece of advice at your own risk.
- You’ll need a grinder for 115-125 disks for modding and for cutting small things. It’s the most common size. With 1mm disk you can cut 20 mm steal sheet 1 meter in width if you follow an easy rule: 7 minutes of work – 30 minutes for cooling. Small, especially cheap grinders are always burn off when you overheat them.
- It’s more convenient to use 1-1.2 mm width disks and 3-4mm disks for grinding and polishing.
- It’s better to use diamond disk while cutting stone, concrete, glass, granite, Dutch tile, ceramic granite and so on. If you don’t want to break expensive disk (from 10$ for one) – richly water the place of cut. It'll be easier to make this work with an assistant - you cut, assistant water it with thick trickle of water (don't forget that water is a good conductor), give water to someone with brains.
- There is a special brush for metal grinding.
- You can buy a rag disk for polishing.
- There is a disk with glass-cloth on a sticker for grinding or polishing flat surfaces. Glass-cloth can be of any number.
- When you work with thin metal you easily make a shape cutting with an old disk with minimal diameter. You can make an ideal hole 60mm in diameter.