Hello,

I was trying to cut some paving slabs at the weekend. I was using a
diamond blade and it was heavy going. I thought at first that the
slabs were just very tough.

I looked at the blade and there was plenty of diamond left but the
diamond patches had a hint of brown. I read here that if the blade
overheats it will turn a brown colour and that the glue can soften and
the diamonds sink beneath the surface.

Could this be what happened? It was a cheap silverline disc from
toolstation. I had an equally cheap disc from aldi that I put on
instead and it cut like a knife through butter, so it was the blade,
not a tough slab.

Isn't there a trick to rejuvenate worn blades? Do I have to cut a
couple of bricks? Or should I just bin it?

How is the best way to prevent overheating? I would think that if you
keep lifting the blade out to allow it to cool, this will make cutting
a straight line quite difficult to achieve? Surely it is best to leave
the blade in the slab. Is the trick to keep the blade in the slab but
let it move at its own pace rather than force it?

Thanks,
Stephen.