How to Change a Sanding Disc on a Grinder

Changing a sanding disc on a grinder, typically an angle grinder fitted with a backing pad, involves securing the disc to the spindle using a retaining nut.

To change a sanding disc on a grinder, you generally hold down the spindle lock button to prevent the shaft from turning, unscrew the retaining nut, remove the old disc and backing pad if necessary, place the new disc and backing pad, and then secure it by screwing the tapered nut back on finger tight while still holding the lock button.

Detailed Steps for Changing the Sanding Disc

Follow these steps for safely and effectively changing a sanding disc on your grinder:

1. Ensure Safety First: Always unplug the grinder from the power source before attempting to change any discs. Wear appropriate safety gear, including gloves and eye protection.
2. Access the Disc: If your grinder has a guard that obstructs access, you may need to adjust or temporarily remove it according to the manufacturer's instructions.
3. Remove the Old Disc:
   • Locate the spindle lock button, usually near the head of the grinder.
   • Press and hold the spindle lock button to prevent the spindle from rotating.
   • Use a spanner wrench (often included with the grinder) that fits the retaining nut, or in some cases, simply grip the nut.
   • Turn the retaining nut counter-clockwise to loosen and remove it. Note that some grinders have a quick-release nut that doesn't require a spanner.
   • Once the nut is off, remove the outer flange (if present), the old sanding disc, and the backing pad.
4. Prepare the New Disc: Ensure you have the correct size and grit sanding disc for your task, along with a compatible backing pad designed for your grinder's spindle size.
5. Install the New Disc:
   • Place the backing pad onto the grinder's spindle.
   • Align the new sanding disc over the backing pad and the spindle.
   • Place the outer flange back on, if applicable.
6. Secure with the Tapered Nut:
   • Take the tapered nut (as mentioned in the reference, the "tapered. Nut that goes on the top of that").
   • Thread the tapered nut onto the grinder's spindle over the disc and backing pad.
7. Tighten the Nut:
   • Press and hold the spindle lock button ("put your finger on the lock on the underside").
   • Turn the tapered nut clockwise.
   • Tighten the nut firmly ("doing it up finger. Tight."). While the reference mentions finger tight, it's crucial to ensure the disc is secure. Often, a final slight turn with a spanner wrench is needed, but avoid overtightening, which can damage the disc or grinder. Always follow your tool's manual for specific torque recommendations.
8. Check the Installation: Release the spindle lock and manually spin the disc by hand to ensure it is properly seated and doesn't wobble.

Key Components

Understanding the parts involved makes changing the disc straightforward:

• Sanding Disc: The abrasive material used for sanding.
• Backing Pad: A flexible or semi-rigid pad that supports the sanding disc and attaches to the grinder's spindle.
• Grinder Spindle: The threaded shaft on the grinder where the backing pad and disc are mounted.
• Spindle Lock Button: A button that locks the spindle rotation for changing accessories.
• Retaining/Tapered Nut: The nut that screws onto the spindle to hold the disc assembly in place. The reference specifically calls this a "tapered nut."

Summary Table: Changing a Sanding Disc

Following these steps ensures your sanding disc is securely attached, allowing for safe and effective use of your grinder. Always consult your grinder's instruction manual for model-specific guidance.