"marine" glass?

[Bornslippy]

I'm trying to source glass to replace some that are cracked in our 70's ketch. A (landlocked) supplier has just declined on the basis that their toughened 6mm glass is not "marine", which was a shame as they were otherwise by far the cheapest. They did not give any more details. What do they mean? I have heard that thermally toughened glass may not be optically great but that isn't really an issue. The thickness is what it is, as we are not changing the (rather lovely, brass) portholes. They are situated above the freeboard deck. We are not commercial and well less than 24m. Any ideas if there is actually anything I should be concerned about in using "any old" toughened glass?

 

[MoodySabre]

I had my boat windows reglazed by Houdini in tinted toughened glass. The word Marine was not used. Someone on here said that it could shatter if hit by a shackle. I can't imagine in what circumstances this might happen. Give Houdini a ring - they will know all about boat windows.

 

[Iliade]

Try Lewes Glass, they made up new glass for my Centaur. It has to be cut to size, polished etc before toughening so does have a lead time. It can be kite marked if you so require, but that was about £15 per mark.

As far as I am aware there is nothing special about the stuff used in yachts.

[crossed posts]

 

[snowbird30ds]

Go back to the supplier and ask for the same stuff, for your shed obviously, nowt to do with a boat.

 

[lustyd]

Even if "marine glass" were a thing today it almost certainly wasn't in the '70's!

 

[MoodySabre]

Another alternative might be laminated glass as that won't shatter.

 

[pandos]

I replaced a section of my windshield with toughened glass from a normal glazing company a few years ago (10 years or so) it has holes and was shaped and then toughened. worked fine since, I never heard of marine glass...the company i used would be pretty technical and careful, mine is etched with an en no or something sililar.

I'd say the guy was talking through his hat...

 

[pandos]

Another alternative might be laminated glass as that won't shatter.

laminated will not shatter but if twisted or bent it will crack, and if hit pieces can fly (I used to make security screens)
You could go mad and get toughened laminated... that would be incredibly strong but probably needlessly so.

I have laminated glass in my small port lights for the last 16 years. (note to self must check the solidity of their bonding...) 6.4 laminated should be perfect for your small port lights..

 

[Bornslippy]

laminated will not shatter but if twisted or bent it will crack, and if hit pieces can fly (I used to make security screens)
You could go mad and get toughened laminated... that would be incredibly strong but probably needlessly so.

I have laminated glass in my small port lights for the last 16 years. (note to self must check the solidity of their bonding...) 6.4 laminated should be perfect for your small port lights..

I haven't found anyone who does toughened laminated in any applicable thickness - all seem to start at 10mm - so was looking at 6.4mm laminated float. Unsure whether this or toughened 6mm would be better though.

 

[neilf39]

Eagle boat windows just put 6mm toughened glass in my boat windows. Give them a call and ask who they use. They order it and it has a lead time to be cut to shape etc.

 

[pandos]

I haven't found anyone who does toughened laminated in any applicable thickness - all seem to start at 10mm - so was looking at 6.4mm laminated float. Unsure whether this or toughened 6mm would be better though.

6.4 lam is (not toughened ) is what I used in my portlights, my logic being that they may crack but would not disappear into tiny fragments, and I let plenty of sikaflex around them to let them move rather than be twisted, I they are about 12 by 4 inches.

When I spoke of splintering of laminated I was having a brain fart and thinking about my own windshield, which is susceptible to swing winch handles and ropes with heavy blocks on the end, when thing go wrong

 

[Boathook]

I have laminated glass in my small port lights for the last 16 years. (note to self must check the solidity of their bonding...) 6.4 laminated should be perfect for your small port lights..

I used laminated once and water got between the glass and it clouded over. Changed to toughen from a local glass supplier. No problem about shape, but they cut to size etc and then send away for treatment.

 

[Rappey]

if there is actually anything I should be concerned about in using "any old" toughened glass?

Not at all. Toughened glass is 5 times stronger than laminated and stock annealed glass. It's got to be much stronger than what you currently have as toughened can't crack but shatters into tiny cubes. The smaller the cubes when broken the better the quality of toughening.
It's a little strange that a glass supplier thinks there is "marine " glass ?
An advantage to laminated is that the film between the glass will stop the glass falling out when broken but is vunerable to damp getting in between and causing the laminate to go "foggy".
Toughened is easier to scratch.

 

[pandos]

Not at all. Toughened glass is 5 times stronger than laminated and stock annealed glass. It's got to be much stronger than what you currently have as toughened can't crack but shatters into tiny cubes. The smaller the cubes when broken the better the quality of toughening.
It's a little strange that a glass supplier thinks there is "marine " glass ?
An advantage to laminated is that the film between the glass will stop the glass falling out when broken but is vunerable to damp getting in between and causing the laminate to go "foggy".
Toughened is easier to scratch.

Toughened if scratched deeply will shatter. The outer skin is like a balloon.

If you seal the edge of laminated with sufficient sikaflex in a frame it will not wick water. Modern vehicle windshields are laminated.

Certaim types of silicone will attack the laminating layer, this can cause the wicking/whiteness/delamination.

 

[Alex_Blackwood]

I'm trying to source glass to replace some that are cracked in our 70's ketch. A (landlocked) supplier has just declined on the basis that their toughened 6mm glass is not "marine", which was a shame as they were otherwise by far the cheapest. They did not give any more details. What do they mean? I have heard that thermally toughened glass may not be optically great but that isn't really an issue. The thickness is what it is, as we are not changing the (rather lovely, brass) portholes. They are situated above the freeboard deck. We are not commercial and well less than 24m. Any ideas if there is actually anything I should be concerned about in using "any old" toughened glass?

Have you tried these people? Glass supplier | Atkinson's Glass & Mirror Centre Ltd

 

[steveinnice]

I'm trying to source glass to replace some that are cracked in our 70's ketch. A (landlocked) supplier has just declined on the basis that their toughened 6mm glass is not "marine", which was a shame as they were otherwise by far the cheapest. They did not give any more details. What do they mean? I have heard that thermally toughened glass may not be optically great but that isn't really an issue. The thickness is what it is, as we are not changing the (rather lovely, brass) portholes. They are situated above the freeboard deck. We are not commercial and well less than 24m. Any ideas if there is actually anything I should be concerned about in using "any old" toughened glass?

good quality 6 mm Poly /acrylic? Much cheaper and easier to work yourself and very strong. You can replace it if it becomes scratched and wont fill your cabin with glass shards/pellets if broken.

 

[steveinnice]

I replaced a section of my windshield with toughened glass from a normal glazing company a few years ago (10 years or so) it has holes and was shaped and then toughened. worked fine since, I never heard of marine glass...the company i used would be pretty technical and careful, mine is etched with an en no or something sililar.

I'd say the guy was talking through his hat...

Or he underquoted and then realised, so made up some excuse. That will become obvious if you go back and ask for it for your shed as another poster has suggested.

 

[pandos]

good quality 6 mm Poly /acrylic? Much cheaper and easier to work yourself and very strong. You can replace it if it becomes scratched and wont fill your cabin with glass shards/pellets if broken.

That stuff never stasys truly clear for long and scratches too easily.

 

[Iliade]

There is another variant called anti-bandit glass, but I would only bother with it if I were contemplating the Southern Ocean without storm boards.

 

[Zing]

Specify laminated toughened glass. It’s essentially bullet proof glass, but thinner.