Just smash it? Removing toughened glass

[Otter]

We need to replace two of the windows in the wheelhouse with Perspex so we can insert large vent hatches in them. The glass panes are toughened so we can't put the vents in them.

The windows sit at a reverse incline so if they break, all the little pieces will fall into the wheelhouse. The panes are simply Sikaflexed in place.

My crazy plan was to get two old bed sheets, gaffer tape them so they cover the window either side, like the pieces of bread in a sandwich. Then smash the glass with a hammer on one of the sheets - being toughened it should just break into a million crumbled bits of glass???

Then carefully untape the sheets and throw the lot away, scrape off the sika with its bits of glass attached and sika in place the Perspex sheets.

Sounds like a plan, but is it a good one? I described it to my wife who said "please ask the forum first darling"...

 

[Ex-SolentBoy]

Clear Fablon on the inner side.

 

[pvb]

Sounds like a good plan. Or you could stick clear self-adhesive plastic on both sides of the glass instead, then you be able to see what's happening. Whichever, you'll need to have a vacuum cleaner handy.

 

[aquaplane]

Some sort of sticky film on one or both sides sounds good but I would be tempted to try to get it off in one piece.

You are going to have to clean up the edges anyway so why not run a knife round and stick wedges in as you go round. It all comes off in one piece and you smugly pop it into a cardboard box to go to the skip.

When it breaks you can go back to plan A.

 

[vyv_cox]

Your original plan is similar to the one used by windscreen people when removing a broken one.

 

[electrosys]

If you do decide to smash the glass, then Tate & Lyle's Golden Syrup liberally applied to the glass and covered by an old bedsheet - or a newspaper at a pinch - will hold the lion's share of the fragments.
Got that tip from a retired (and reformed) burglar who was rather more concerned with dampening the noise, than catching the fragments.
He only ever had access to one side of the glass - whereas you could treat both sides ...

BTW - a slight tap with a sharp centre-punch in one corner is all it takes to shatter the glass - no need for a sledgehammer !

 

[Otter]

Thanks guys. I'll see if we can get hold of some cheap sticky backed plastic and I'm getting a tin of golden syrup as a standby!

 

[Modulation]

Your original plan is just fine. I had a 1.2 by 1 metre pane of toughened break while installing it last year and I was amazed how "uneventful" the whole business was - no cuts or scratches - just fell to the floor.

 

[Fantasie 19]

I'm getting a tin of golden syrup as a standby!

Handy for putting on toast, and having with mug of tea, after the hopefully successful operation!

 

[Deleted member 36384]

I guess you need to get the glass out as opposed to cutting hole in it. This made me wonder if it is possible cut toughened glass?

 

[rob2]

This made me wonder if it is possible cut toughened glass?

The Problem with toughened glass is that it is permanently stressed. The finished part is moulded and chilled so that the outer skin forms first and isd then pulled into tension as the remaining material solidifies. Any damage to the outer skin and the whole thing just disintegrates.

Rob.

 

[alant]

We need to replace two of the windows in the wheelhouse with Perspex so we can insert large vent hatches in them. The glass panes are toughened so we can't put the vents in them.

The windows sit at a reverse incline so if they break, all the little pieces will fall into the wheelhouse. The panes are simply Sikaflexed in place.

My crazy plan was to get two old bed sheets, gaffer tape them so they cover the window either side, like the pieces of bread in a sandwich. Then smash the glass with a hammer on one of the sheets - being toughened it should just break into a million crumbled bits of glass???

Then carefully untape the sheets and throw the lot away, scrape off the sika with its bits of glass attached and sika in place the Perspex sheets.

Sounds like a plan, but is it a good one? I described it to my wife who said "please ask the forum first darling"...

Friend of mine, bought a steel dutch pilot boat & found himself locked out.
Attacked the wheelhouse windows with a lump hammer & still couldn't get them to break.

Best of luck.

 

[BobnLesley]

Safely removing toughened glass...

Many years ago. after much buck passing it fell to me to arrange the task of safely removing some panes which were about 20 x 8' without injuring any of the demolition lads; too heavy to manhandle in one piece, no access for lifting equipment and too dangerous to break at close range.

All it took was a bit of lateral thinking, I got a canvas curtain hung on one side and sand filled canvas curtain on the other, then arranged for a couple of the local residents - I was working the Para barracks in Aldershot - to shoot them out for us; it worked a treat, the labour/plant was provided FOC, but we were billed £6.27+VAT for the bullets they used.

 

[electrosys]

... it worked a treat, the labour/plant was provided FOC, but we were billed £6.27+VAT for the bullets they used.

That's the military mind at work ...

.. for some reason that reminds me of when I was put in charge of a bunch of guys guarding two full hangars of aircraft. Intelligence had suggested that an IRA propaganda attack was possible, so we were all issued with SLR's and a clip of live 7.62mm ammo, which was neatly sealed inside a couple of layers of brown paper with a plastic outer wrapper which sported a white NATO label. We had instructions 'on no account to open the packets unless fired upon', as they were to be returned in exactly the same condition as they had been issued.

 

[yoda]

If you can get a cheese wire under a corner it may be possible to slice through the Sikaflex and remove the windows whole. Otherwise I would go with your plan.

Yoda

 

[Lakesailor]

Your wife is very wise.

I would get two old bed sheets, gaffer tape them so they cover the window either side, like the pieces of bread in a sandwich. Then smash the glass with a hammer on one of the sheets - being toughened it should just break into a million crumbled bits of glass.

Then carefully untape the sheets and throw the lot away, scrape off the sika with its bits of glass attached and sika in place the Perspex sheets.

Thought about getting laminated glass panels made with the cut-outs in?

 

[CreakyDecks]

Is glass toughening an irreversible process? I would phone a glass company and ask if it is possible to have it "un-toughened" then cut and re-toughened!

 

[CreakyDecks]

Having thought about that for a minute it is obvious that starting with new glass would be cheaper than any "annealing" process, even if it was possible!

 

[lenseman]

. . . Then smash the glass with a hammer on one of the sheets . . . .

Don't use a hammer as it often requires three or four large hits before the glass breaks and by that time your catchment system might have moved or fallen.

Use a centre punch (automatic, self-loading type) at a corner of the glass and it will break without any effort at all. That is what car thieves use to get at the laptop on the front seat or the Sat Nav on the dashboard.

 

[Spyro]

Don't use a hammer as it often requires three or four large hits before the glass breaks and by that time your catchment system might have moved or fallen.

Use a centre punch (automatic, self-loading type) at a corner of the glass and it will break without any effort at all. That is what car thieves use to get at the laptop on the front seat or the Sat Nav on the dashboard.

Once saw a glazier demonstrate how tough thoughened glass was with a hammer. It didn't break. Small sharp screwdriver in the corner and a tap with a hammer was all it took.