Collection: Abrasive Sheet

The abrasive sheet remains the tool of hand sanding and orbital finishing sanders. It folds, cuts, mounts on a block, and reaches what no disc can touch: internal corners, mouldings and small parts.

The 11 references in the catalogue

• Paper backing: 3M Wetordry 401Q and 734, for wet sanding.
• Non-woven backing: 3M Scotch-Brite 7447+, CF-HP pads. See our non-woven abrasive sheets.
• Mesh backing: Mirka Abranet sheets.
• Micro-abrasive films: 3M 261X lapping film. See our micro-abrasive sheets.

Wet sanding, and why it changes the result

Wetordry sheets are designed to work wet. Water plays two roles that dry work does not replace.

It carries away the particles before they stick between the grains. The abrasive therefore does not clog and keeps its cutting ability much longer.

It lubricates the cut, which reduces local heat build-up and gives a much more even surface for the same grit. On a finish before varnishing or polishing, the difference shows.

Two precautions: rinse regularly, otherwise the abrasive slurry scratches; and check that the substrate tolerates water, which is not the case for bare wood or an uncured filler.

Micro-abrasive film, for what paper cannot do

A lapping film carries the grain on a polyester film of very constant thickness. Where paper has irregularities of a few microns, enough to mark an optical surface, the film gives a flatness that paper cannot reach.

It is the abrasive for very fine finishes, lapping of bearing surfaces and work where final roughness is measured rather than judged by eye.

Block or hand

Sanding a flat surface by bare hand always gives a wavy surface: the fingers press harder than the palm, and the hand follows the hollow instead of removing it.

A block spreads the pressure and takes down the high points first. On a flat surface it is essential. On a shape it is the opposite: the hand or a sponge is right.