Sanding Discs NZ
Our automotive sanding discs are designed for efficient and consistent work that covers every stage of circular sanding, from shaping filler to keying primer, with Norton and AutoFinish ranges available.
Choosing Car Sanding Discs for Each Repair Stage
Circular sanding discs on a dual action sander do most of the levelling work in a repair, and each grit should remove the scratches left by the one before. 3M's process charts call for block sanding body filler at P120 then P180, feather edging at P180 to P220 and refining at P320, then sanding primer at P320 to P500 before paint. Skipping too far ahead in grit leaves deep scratches the finer disc struggles to remove, and these can appear through basecoat. Fit an interface pad when sanding curved panels and swage lines to spread pressure and avoid cutting through edges.
Sanding Discs FAQs
Which hole pattern do I need for my sander?
Match the disc to the holes on your sander's backing pad. If they don't line up, the extraction holes are blocked, and dust builds up under the disc. Our auto sanding discs come in 15-hole 150mm and 8-hole 125mm formats.
When should I use an interface pad?
Use one on curves, contours, and body lines, where a firm pad can make the disc cut through edges. 3M advises a soft interface pad when sanding curved areas. Leave it off for flat filler work, where a firm pad helps keep the panel straight.
What grit should I finish primer with before the basecoat?
Check the technical data sheet for your paint system, as each one lists its own final grit. 3M's process finishes large primer areas at P400 to P500, with P600 as a last step for critical colours. For hand flatting around edges, use wet and dry sandpaper.
Can I use 150mm discs on a 125mm sander?
No. Use car body sanding discs that match your backing pad's diameter. An oversized disc overhangs the pad, wears unevenly, and can catch on panel edges. Our range covers both 150mm and 125mm sanders.