A B C D E F G
Cutting shapes
As you get more proficient at straight lines,
start to curve them gently and see if they
break any differently. Try the cuts in fig 4 .8.
You should find that gentle curves (A and B)
break well but sudden changes of direction
(C), convoluted lines(D), thin edges (E), deep
curves (F) and cuts to a point (G) may not
break properly.
As you get more proficient at straight lines,
start to curve them gently and see if they
break any differently. Try the cuts in fig 4 .8.
You should find that gentle curves (A and B)
break well but sudden changes of direction
(C), convoluted lines(D), thin edges (E), deep
curves (F) and cuts to a point (G) may not
break properly.
There are other breaking methods that help to overcome these problems but the fact is there are some
shapes that cannot be cut from glass by conventional means. And even when they are finally worked
out, they are very likely to break apart in assembly, installation, or high winds. Example E is difficult
and inherently weak. Example G is not possible because one of the score lines will run to the far edge.
(This cut could be achieved with a glass saw or a via small hole drilled at the apex, then the scores
made and gently broken. It will almost inevitably break up at some later stage, however.)
shapes that cannot be cut from glass by conventional means. And even when they are finally worked
out, they are very likely to break apart in assembly, installation, or high winds. Example E is difficult
and inherently weak. Example G is not possible because one of the score lines will run to the far edge.
(This cut could be achieved with a glass saw or a via small hole drilled at the apex, then the scores
made and gently broken. It will almost inevitably break up at some later stage, however.)
Tapping
Deep concave cuts or sharp curves can be scored and then broken out by tapping from underneath
with the metal head of the glass cutter (not the wheel!!).
Each tap should be an accurate swift "poke" at the underside of the scoreline with the cutter held at
right angles to it (Fig 4.9). A crack should appear in the glass and advance with each tap. The
temptation is to flail away madly at the glass to get it broken out quickly. The drawback to tapping is
that every time you tap the glass, it cracks through on a slightly different angle. Once the waste is
broken away you will discover a very rough edge to the glass. To partly avoid this, make each tap
gentle and accurate rather than erratic and heavy. After tapping out a shape you will need to use a
glass grinder to file down the edges so use tapping only as a last resort - running a cut is cleaner,
faster and quieter.
Deep concave cuts or sharp curves can be scored and then broken out by tapping from underneath
with the metal head of the glass cutter (not the wheel!!).
Each tap should be an accurate swift "poke" at the underside of the scoreline with the cutter held at
right angles to it (Fig 4.9). A crack should appear in the glass and advance with each tap. The
temptation is to flail away madly at the glass to get it broken out quickly. The drawback to tapping is
that every time you tap the glass, it cracks through on a slightly different angle. Once the waste is
broken away you will discover a very rough edge to the glass. To partly avoid this, make each tap
gentle and accurate rather than erratic and heavy. After tapping out a shape you will need to use a
glass grinder to file down the edges so use tapping only as a last resort - running a cut is cleaner,
faster and quieter.
