What glass in our windows?

Zing said:
Windscreen glass can be both toughened and laminated. I would have thought that was the strongest, safest and the most suitable for a boat?
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I am sure you right but I think my proposal would meet my need, a strong glass with less chance of fragments strewn all over the forecabin. Easy to do and costing less.
 
The ultimate glass spec for your boat would be toughed and laminated. It does exist and you can buy it. We used to spec it for glass roof lights over shopping centres. I have no idea how expensive it is but its commercially available.
 
Can toughened glass be drilled? Was wondering if it might be an alternative to Perspex for my doghouse windows? Problem might be that the windows are fixed onto the grp with dome nuts, there is no window frame as such, so that means many holes drilled along the edges, is this practical with toughened glass?
 
The glass would be drilled and shaped first, then toughened.
In your scenario I would imagine a stainless flat strip round the edges would be better over the glass to secure it
 
OK

Glass on cars are either toughened OR laminated not generally both unless for bullet proof purposes.

Once toughened glass generally be drilled or cut, BUT some of mine were slightly over size and managed to grind a mill or 2 from the edge without breaking. It was that or make new so no loss but possible gains..

Clamp all glass into a rebated frame with some rubber molding between the glass and the frame. I used 6 mm thick foam strip wrapped around the glass.

Any direct contact with metal of a hard surface could shatter the glass.

I have 7 toughened/laminated windows in my steel wheel house and my current boat and also 9 toughened/laminated windows in an new wooden wheel house on an old ferro boat I have been working on up to the lockdown.
 
You can certainly cut toughened glass in half with an angle grinder and grind the edges down to size.
I've never tried it but would imagine it's possible to drill a hole through it too.
No idea what that success rate would be like though.
 
Rappey said:
You can certainly cut toughened glass in half with an angle grinder and grind the edges down to size.
I've never tried it but would imagine it's possible to drill a hole through it too.
No idea what that success rate would be like though.
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I would suggest you try it and post the video

Straight Laminated glass you can cut and drilled

Toughened glass has induces stress in the glass and if you release the stresses at one point the glass shatters.

You cn grind the edges because the edges may not have the stresses going right to the edges. If it does or you gring too much and release the stress it will shatter
 
Rappey said:
I have no reason to . I would cut a piece the correct size rather than try to cut a smaller piece from a large one. Im just saying it is possible.
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I did have cause to try as the original windows for my Boat in my sig were made too large even through the templates were correct. I called the firm in who made then and they agreed to remake them at their cost. I know they were remade as I also retained the overside ones.

If it was possible was possilbe to cut the oversize windows the supplier would have done that rether than having to pay to the new ones.

2 of the remade one were also a little oversize and I agreed to try to grind off the excess, I watched this being done, on the understanding that it the windows shattered the supplier would remake again at their cost.
 
For the supplier It's easier to cut new glass rather than try to take a few mm off one side. Time is money and glass is cheap.
 
Rappey said:
For the supplier It's easier to cut new glass rather than try to take a few mm off one side. Time is money and glass is cheap.
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The glass i cheap by the labour costs of the toughening and laminating is not. I also think the toughening was subcontracted so was a direct cost.

As I said I watched then grinding 2 of the remade windows on their own machine in their own factory took no more that 1/2 hour each.

Process

Glass cut to templates
Each panel is heat treated to toughen each panel.
2 panels the laminated together to make up the final window.

As you say time is money and th glass part is cheap it the subsequent processing where the cost is.

Grinding off a few mm if possible would be much cheaper than making all new.


 
Rogershaw said:
I did have cause to try as the original windows for my Boat in my sig were made too large even through the templates were correct. I called the firm in who made then and they agreed to remake them at their cost. I know they were remade as I also retained the overside ones.

If it was possible was possilbe to cut the oversize windows the supplier would have done that rether than having to pay to the new ones.

2 of the remade one were also a little oversize and I agreed to try to grind off the excess, I watched this being done, on the understanding that it the windows shattered the supplier would remake again at their cost.
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My best guess is that the tensile/compressive stresses didn't extend to the edges of the glass. If you look at a toughened windscreen in the right light you can see where the cooling air blasts were directed, and those zones generally start a couple of inches from each edge. It might be possible to drill through near the edge, but it's not a risk I would take. The idea of cutting tempered glass across the middle with an angle grinder is, to quote Bertie Wooster, pure banana oil.
 
JumbleDuck said:
My best guess is that the tensile/compressive stresses didn't extend to the edges of the glass. If you look at a toughened windscreen in the right light you can see where the cooling air blasts were directed, and those zones generally start a couple of inches from each edge. It might be possible to drill through near the edge, but it's not a risk I would take. The idea of cutting tempered glass across the middle with an angle grinder is, to quote Bertie Wooster, pure banana oil.
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Yes that is the case and why we were able to grind a few mm off the edge.

I would not risk drilling a hole near the edge either. Drill before toughening.

What you may think is cooling blasts could be but some car windscreens are zone toughened now so a small viewing portision of the screen can be clearer to give better when driving with a shattered screen.

Didn't know banana's had any oil must look next time I am i Natal.:confused:o_O:rolleyes:
 
Rogershaw said:
Didn't know banana's had any oil must look next time I am i Natal.:confused:
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Apparently it's used for hair and skin. Isoamyl acetate. smells like banana's.
Jumbleduck is using it to say cutting toughened glass is not possible.
All the youtube videos cutting toughened glass must be fake then ? :rolleyes:
 
Rappey said:
Apparently it's used for hair and skin. Isoamyl acetate. smells like banana's.
Jumbleduck is using it to say cutting toughened glass is not possible.
All the youtube videos cutting toughened glass must be fake then ? :rolleyes:
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I did find one that said "cutting tempered glass for a cat flap using an diamont cutting disk in an angle grinder.

It was in fact cutting a hole in laminated glass.

On of the issues is the term "safety glass" that can mean toughened or laminated or even polycarb or even perspex.


So banana oil does not come from bananas unlike sunflower oil it but just tastes and smells like bananas
 
I like this one as he sings his way through the video. That took some beating to shatter it.

This guy uses a wet wheel to cut but like many videos they call it tempered glass when it may not be?
 
Rappey said:
I like this one as he sings his way through the video. That took some beating to shatter it.

This guy uses a wet wheel to cut but like many videos they call it tempered glass when it may not be?
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I would love to have a sample of the glass they used as the first one look like laminated as when it was hit on the corner it did not shatter as one of mine did when I dropped it from 300mm on to one of the corners onto the concrete deck of a boat.

when grinding glass you need to flood the ground edge otherwise the glass will chip .

This looks to be a toughened and laminated glass as it broke like mine did when I dropped it onto a corner from 300mm
https://www.scienceabc.com/wp-conte....com/wp-content/uploads/2016/08/giff.gif-.gif

Why Do Cars’ Glass Break In Such Small Pieces?

As I said there is some misunderstanding as to what tempered . toughened and laminated really is

You need to see it and work with it.

but if you think you can cut proper toughened glass with an angle grinder go for it.
 
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