If we are talking specifically stove glass and corrosive cleaners it's to do with these combined with the high heat glass. Since he's spent the last 15 years dealing with stoves i tend to believe him although i do agree in general to what ur saying

I too am awaiting the answer to that one!

I mean glass is BREAKABLE. But I understand it to not corrode, stain or fade so I am interested in detail about this 'deterioration'.

Sorry Jet&Copper I posted before I read your last.

What I would like is a bit of ELABORATION on his statement.
Not just that 'he said it does'!

Family of chemists here mate!

I should add - you DO know WHY they use special glass for these halogen cooktops?

I shall ask him for a proper explanation when he comes in (and actually listen to him for a change ) He goes on about these kinds of things bloomin constantly!

Molecular Geneticist here so I don't just take on these things on hearsay either! Much to his annoyance.

When it comes to old glass, that's different. Apparently glass is actually still a liquid, and over the passage of many decades, it can change its uniformity. I don't remember the details but it's something like gravity still affects it and over time (a long time) it can thicken downwards while the top part becomes more fragile.

Certainly seemed true in the Victorian house I lived in, in London, where the sash windows were original 1880's. They were also slightly wavy to look through, and one large pane in a front sash window snapped when someone casually leant against it.

Would someone who knows about these things now tell me I didn't dream that part about the liquid??

i have no idea MerlinsMum! I'm vaguely thinking with the stove thing thst it might be something about a protective coating to protect from the extreme temperatures?? I could have made that up in my head though? This is annoying me now!

You did not dream it at all. But they do use a very DIFFERENT type of glass these days for these Halogen cookertops. Ceramic glass? Dunno will have to look it up if I can be arssssed to!

I never believed a blerdy WORD any of my husbands said to me lol!

*and Jet you ARE making me laugh. Thank you for that. I need the humour!

*dammm editing again now! Please don't get ANNOYED Jet! Just keep on saying things that make me laugh!

Hehe I'm not remotely annoyed! You will be well laughing when he comes in and tells me I'm talking a load of bollocks which is whats going throygh my head now ha!!

Btw i have just noticed im not talking about halogen cookertops but wood burning stoves so we could actually just be talking about totally different things!!!!