HI Simon

sm_jamieson wrote:
I never had issue with diamond cutting disks before. I got cheap-ish
ones, and they just worked.
However, yesterday I had about 80 facing brick cross-cuts to make
(cutting tapered headers etc), using 230mm disks in angle grinder
stand. The first disk was a cheapy "titan" (20 quid) that I had been
using for a few months cutting bricks now and then. This was worn
quite low and it suddenly stopped cutting, the brick vitrifying as if
if there were no diamond left. Off to screwfix to get another titan,
since the last had quite a good life. This disk got through 60 cuts
OK, and suddenly stopped cutting like the last, although there was
loads of the cutting band left, and diamonds could be seen on the
sides, but the bottom almost looked "polished" and rounded off.
Long story short, another "clarke" disk from nearby machinemart (20
quid) did not appear to even start cutting. I put that down to
learning experience (it will cut aircrete !!!). Finally, screwfix, got
the Edge GP turbo or something, that took a short while to get going,
but then was pretty good (although no better than the titan, although
it may last longer).
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. So perhaps this is
the problem with all the disks.
If so, whats the best mateial to cut to expose some more diamonds ?
All the disks were general purpose medium/hard versions.
I would probably have been better off getting an expensive disk for
hard material including engineering bricks at the start of my building
work, but there you are.
However, I seem to be lacking some knowledge about the use of there
disks.
Any tips ?
Simon.

In the lapidary (gemstone cutting) business, the advice for rejuvenating
a glazed-over diamond saw used to be to make a couple of cuts with the
blade into a discarded grinding wheel. The idea was to wear away the
edge of the sawblade to reveal a new diamond cutting surface.

I seem to recall that the better blades have a thicker layer of diamonds
(which this technique relies upon) - whereas cheaper blades may only
have a very thin 'surface layer'of diamonds - and when they're gone
you're stuck !

Hope this helps

Adrian