Let it run for a minute before you do any grinding. Then grind gradually with a light pressure until the wheel warms up. Cold can cause a wheel to shatter. Side pressure may break a wheel that is not specifically designed for side-pressure grinding. Portable grinders and brushes are difficult to handle because of their size and weight.
Extra care is needed to avoid injury and to protect the grinding wheel and brushes from damage.
When using a portable grinder, hold it firmly with both hands. When finished, make sure that the grinder has completely stopped turning before you lay it down. Develop a system of racks, bins and tool panels to make it easy to find the right tool or materials quickly. Don't store tools, supplies or spare parts in the aisle or on the floor where they become tripping hazards. Keep other flammable materials away from heaters and welding areas to prevent fire.