I need to cut about 8mm off the diameter of a round mirror to fit it into my smashed mickey mouse Range Rover bonnet mirror

Can I do it with the little glass tools (below) that I must have 11 of or am I asking for trouble?

Anyone know how to go about it?

George

Good luck
Rog

The problem that you will have is cutting an exterior curve in one go. That tool will do the job, but I suggest you draw a line onto the glass with a marker pen, then take a number of larger radius cuts to try and get the correct shape. To cut a complex shape in glass, you score the line (make sure your glass cutter has oil in it - if not, cut through a film of light oil). Then you put a little pressure on the cut with a pair of blunt nosed pliers. Whilst applying the pressure, use the handle of the cutter to tap the glass - quite gently so that you don't smash it. Work your way from one end to the other - you should manage to do it without breaking. If there are small sharp lumps left at the end, use a bench grinder to get rid of them. Hope this helps.

Cool thanks guys.

So hold the glass outside the score with the pliers and tap it where - inside the score? And so I'm smearing oil on the glass to lube as I score yeah? did I just complicate things

Do you think it's worthwhile scoring a perpendicular line out to the glass edge every few cm's to try cut it in sections?

Underneath the glass, directly under the cut. The lady wife who does loads of stained glass stuff says that you can either use pliers, or tap the glass - the more complex the shape, the more likely it is you should tap it. With a simple curve with perpendicular lines scored outwards, she says to just be careful and use pliers.



Mrs. T says that the oil has a triple function. It stops the blade blunting so quickly. It lubricates the rotating part of the blade, and it fills the score line that you have just made. Glass is a VERY thick liquid, and the scoring just breaks the surface tension.



Yup - apparently that's a very good idea.

All of that or much simpler - pay a friendly local glass suppliers a beer token or two to cut it with a diamond scribe for you ... causes much less bad language!

Andy

Thats some good advicin'

Cheers I'll let you know how I get on and post pics of the cuts and bandages...

its a little bit of a myth, about glass being a liquid....
Glass is a uniform material of arguable phase, usually produced when the viscous molten material cools very rapidly to below its glass transition temperature, without sufficient time for a regular crystal lattice to form.
most material scientists regard it as a ceramic.

Go take a look in an old church and review you position .

The glass, if it is old enough is visibly thicker at the bottom due to creep.

Agreed - but I doubt that his Rangie is that old...

Or not....

Research is your friend....

This is what is called an urban myth.

I suggest you go and take a look in a materials science book, and review your position.

cheers red 90.... you saved me having to get off my arse and find some evidence.

Have you still got any material science books from when you were at school Bish?