toughened or laminated glass?

[voicilesrosbifs]

Refurbishing 4 saloon windows, SWMBO says why not replace the glass as well as the seals. Existing glass is 20 years old toughened and kitemarked, 5mm, few light scratches but usable. Glazier can make replacements in toughened glass but they will be around 40 quid each. Ouch!

Glazier suggested using laminated glass instead - about a tenner a window. This is 2 sheets of 3mm window glass with a clear plastic film between them, so total width is 6.4mm. This will fit into the existing frames, but:

1. Opinions about using laminated instead of toughened?
2. More glass means less mastic to handle expansion/contraction. Asking for trouble?

 

[sailorman]

Refurbishing 4 saloon windows, SWMBO says why not replace the glass as well as the seals. Existing glass is 20 years old toughened and kitemarked, 5mm, few light scratches but usable. Glazier can make replacements in toughened glass but they will be around 40 quid each. Ouch!

Glazier suggested using laminated glass instead - about a tenner a window. This is 2 sheets of 3mm window glass with a clear plastic film between them, so total width is 6.4mm. This will fit into the existing frames, but:

1. Opinions about using laminated instead of toughened?
2. More glass means less mastic to handle expansion/contraction. Asking for trouble?

the laminate if it breaks will have sharp shards & pieces can fly off.
the toughened will shatter but no sharp splinters

 

[earlybird]

£40 per window for toughened glass sounds a tad expensive to me. I had new aluminium frames made by C&J International Windows. The old glass looked a bit second-hand after 35 years and only some was kite-marked. At their suggestion I went for new, toughened glass. I was surprised how little it cost, roughly £10 per window IIRC.

 

[PCUK]

I was quoted £35 per square metre for toughened which seemed reasonable. Sounds like you need to shop around.

 

[nimbusgb]

the laminate if it breaks will have sharp shards & pieces can fly off.
the toughened will shatter but no sharp splinters

If you think toughened glass has no sharp edges then you are mistaken. I have several scars where pieces of shattered older car toughened windows have taken pieces out of fingers.

The advantage of laminated is that it will retain some level of water tight integrity when compromised whereas a toughened window will leave you with an empty window frame and a boat full of small square bits of glass.

I know which I'd prefer on a boat!

Laminated

vs

Are you sure he got the prices the right way round? Laminated glass is normally used when there is a possibility of human impact or where the glass could fall if shattered ( car windscreens, hurricane prrofing etc ). Because of the intermediate plastic layer laminated glass is a pig to cut to size and should only be done by professionals. It is usually manufactured 'to size' ie a car windscreen

 

[Stemar]

I'm pretty sure my local glazier stocks laminated glass. The last time I wanted a pane, he gave me the 3rd degree 'cos elfin safety means it has to be used in most doors and low windows. He'll cut it to size with no problem, but he makes cutting 3mm off a pane of ordinary glass look easy too...

AFAIK, cutting toughened glass results in lots of little cubes, so it has to be cut to size then toughened, which might explain the price.

 

[wotayottie]

is laminated ordinary glass as tough as toughened glass? I would have thought it was much more likely to crack when knocked by (say) a boathook.

 

[rogerthebodger]

I fitted 7 big windows to the wheel house of my boat and due to the size I needed the strongest glas available for the available thickness.

Toughened glass has a greater impact strength than the same thickness as laminated glass but if broken will leave a big hole in your boat.

I went for a laminated glass of two sheets of toughened glass so I have the best of both.

The smallest window is about 500 mm by 800 mm and the biggest the front one is 1200mm by 800 mm

It is also possible to trim a toughened glass by grinding the edge as the heat treatment does not go all the way to the edge as the people who did mine made 2 panels 3 mm over side to my pattern but there is no guarantee the glass will not break.

 

[richardabeattie]

"few light scratches but usable".

That says it all doesn't it - Could they be polished out?

 

[daveyw]

I'm fitting a wheel house with double glazed windows, the outer layer is 19mm bandit glass. A sledge hammer would have problems breaking it. The inner layer is 5 mm toughened. Total price for an 18" panel just over £30

 

[Ubergeekian]

£40 per window for toughened glass sounds a tad expensive to me. I had new aluminium frames made by C&J International Windows. The old glass looked a bit second-hand after 35 years and only some was kite-marked. At their suggestion I went for new, toughened glass. I was surprised how little it cost, roughly £10 per window IIRC.

C&J did a pair of Hunter windows for me earlier this year. The additional cost of toughened glass over perspex was less than £1.50 per window ...

 

[Boathook]

Refurbishing 4 saloon windows, SWMBO says why not replace the glass as well as the seals. Existing glass is 20 years old toughened and kitemarked, 5mm, few light scratches but usable. Glazier can make replacements in toughened glass but they will be around 40 quid each. Ouch!

Glazier suggested using laminated glass instead - about a tenner a window. This is 2 sheets of 3mm window glass with a clear plastic film between them, so total width is 6.4mm. This will fit into the existing frames, but:

1. Opinions about using laminated instead of toughened?
2. More glass means less mastic to handle expansion/contraction. Asking for trouble?

I tried laminated glass quite a few years ago on deck windows and found that after a few years it started to delaminate. had to rebuild windows due to leaks and installed toughened glass. Also toughened glass is ment to stand knocks better, but when it goes ....

 

[Alrob]

As someone who is in the glazing business with access to a £1m toughening plant I recently changed a couple of cracked units - so which type of glass do you think I used 6.4m Lam or 6mm Tuf ??

 

[cimo]

have you written off plexiglass as a possibility?

easy to cut & fit, & you will have leftover spare onboard for emergencies?
(can be polished too to remove marks down the line. Available in your 5mm.

just a thought.

 

[ccscott49]

Laminated with toughened glass sounds the dogs bits to me.

Whats armoured glass? Just thick toughened?

 

[rogerthebodger]

armoured glass tends to be multi layer laminated glass (bullet resisent)

This is where I got mine from made to order from my patterns.

http://www.reneturck.co.za/products.htm

 

[Avocet]

There are a number of "impact-modified" acrylics around now that have the scratch resistance of an acrylic but also a lot of the toughness of polycarbonate. We use stuff called Plexiglass "Resist 65" at work and it's pretty good. Also available even tougher (Resist 75 and Resist 100) if you want.

Not sure how long automotive-quality laminated glass would last in a marine environment unless the edges were REALLY well-sealed. I think delamination could become a problem.

 

[Vamoose]

Tougened - V - Laminated

Vehicle Windscreens are Laminated, and modern cars the windscreen is an integral part of the strength of the vehicle.... If Laminated is tough enough to cope with screens the size they are on these monster coaches these days I am sure they are more than strong enough for you.

Windscreens are laminated. This is where two layers of glass are permanently bonded together by a plastic membrane. If something hits a laminated windscreen, like a flying stone, the glass will not shatter. This is because the damaged area sticks to the plastic membrane ..

Avocet makes the point about delamination which is correct.. But if it is properly sealed it should not be a problem

I could go on at length... But I wont...Hope that helps

 

[2Tizwoz]

Tyneside Safety Glass are a major manufacturer who provide a high quality cost effective service I've found them very good to deal with. They will give you the best of advice balancing cost and quality. Their products include toughened and laminated also incorporating polycarbonate.

There's a video on their website showing their production capacity. Not all toughened glass is the same.