"Andy Dingley" wrote in message
...
On 25 June, 09:42, sm_jamieson wrote:

I later read something in the leaftlet that came with the apparently
hopeless clarke disk, saying if the disk stops cutting you may need to
cut some abrasive material to expose some diamonds.

This is usual for bulk abrasive disks (vitirified or sintered), but
not for diamonds.

Bulk abrasive disks can "glaze" on the surface, especially with soft
metals and some clays (hard facing or blue bricks). The trick is
usually to dress the wheel directly with a diamond or hard steel.
Grinding something moderately abrasive (hunk of hard sandstone) can
also help.

Diamond disks are differerent - they've only ever had a thin layer of
diamonds plated into the nickel surface.


Are you sure?
The ones I have from lidl appear to have sintered metal "teeth" with
diamonds throughout.
You get new diamonds as you wear the teeth away.
I can't imagine a diamond blade lasting long if it only has a surface
coating.