On 20/06/2020 11:21, alan_m wrote:
On 19/06/2020 19:59, newshound wrote:


The other useful technique is, after making the score, to gently tap
along the line of it with something like the ball of a ball pein
hammer. Done correctly, it will cause the surface defect to propagate
through the thickness of the glass.

I was shown how to do this with quarry tiles and used it when fitting
the same.Â* Score the glazed top surface with a glass cutter in the same
way as glass and then use a very small light weight hammer

https://tinyurl.com/ya54ypa9

to repeatedly gently tap the back of the tile in the area with the score
on the top surface. The tile will start "ringing" with the note changing
as the crack propagates and breaks along the score line. Not suitable
for just taking off a small amount but OK for a 1/4 of the tile width or
more.


The sort of glass cutters we use in stained-glass tend to have a
weighted brass 'head' (the opposite end to the cutter) - and this can be
used to start the score running.

If you're doing a straight 'edge-to-edge' cut then you shouldn't need to
do any more than tap at the start and end of the score - and the section
in-between will follow the line of the score, if the score has been done
properly.

If you have a sinuous score then tapping at strategic points along the
curve can ensure that the glass behaves - rather than cracking off in
random directions where it wants to..