Making glass look old

[Feltwell]

After Mrs F's little wasp-swatting incident (see "Graham's Top Tips") I decided to replace the glass in that sash with toughened glass, as it's a very large window that is only 10" off the floor, the chances of kids crashing into it one day are fairly high and sometimes safety has to come before aesthetics - so modern float glass that can be toughened it is.

The local glaziers cut me some glass to suit the very-out-of-square window, and I took it to a glass processers this morning who put it through their toughening heat treatment machine whilst I waited. Chatting to one of the glaziers there, he reckoned it was possible to make modern glass look wavy by putting acetone or brick acid on it for at least 24 hours - get 2 sheets, put the acetone/acid on one outside face so it can run down, put some more on the other side and bring the 2 sheets together to trap the mixture.

I'm somewhat sceptical that anything will happen, but this was a major glass processing plant so you'd expect they would know their stuff. He gave me a couple of offcuts of horticultural glass (looks dead flat like float though) to experiment on, so I shall report back in due course..............

 

[Lime]

Its probably the phosphoric acid in brick cleaner that is the main chemical to bring about change to the glass surface.
However I wonder how that would affect the toughening process?
Bearing in mind the process is just a skin effect any sort of etching may weaken the properties of it.

http://corrosion-doctors.org/Household/Glass.htm

Don't go near anything with hydrofluoric acid in unless you know exactly what you are doing.
It will penetrate skin and dissolve your bones even when very dilute.

 

[Penners]

he reckoned it was possible to make modern glass look wavy by putting acetone or brick acid on it for at least 24 hours

I find that you can achieve the same effect by spending several hours in the pub before you look through that window.

 

[Feltwell]

The toughened glass I've just bought I'll leave as is, it was more as an experiment for future occasions. I'll only try brick acid, nothing any stronger.

Penners, I like your thinking

 

[Gareth Hughes]

I wish you'd asked before you replaced the glass. Various safety films are available which are stuck onto the original :roll:

 

[LadyArowana]

I wish you'd asked before you replaced the glass. Various safety films are available which are stuck onto the original :roll:

It's OK Gareth, the glass was already broken because Mrs F was a bit over enthusiastic on the insect swatting ( well that's what we were told anyway :wink: ) so in this case a film wasn't really an option. Interesting you mention it though as I am looking at getting some ( for UV reduction purposes ) in London. I got samples last trip, but didn't get around to doing measurements and ordering.

 

[Feltwell]

LadyA is quite right Gareth, the glass was broken anyway - plus I don't think it was original, it had some flaws in it such as air bubbles but it was very flat compared to the other bits of original glass that are elsewhere in the house. I suspect it was older float glass. Like a lot of Victorian houses that still have their original windows, I've a mixture of original glass and float glass where odd panes have been replaced over time.

Where I can I've retained the original glass, but I will confess to changing some broken panes for float - simply because of time and the need to get a window back into service. Getting hold of Tatra glass would mean a 3 hour drive for me, as generally my sashes have an extremely narrow rebate and aren't terribly square, so I prefer to take the sashes to the glazier and get them to cut the glass to suit rather than working off measurements - quite aside from the cost. It's a compromise that I don't really like but sometimes a compromise has to be accepted.

One minor nod to originality - toughened glass is usually marked with a small etched symbol on the glass, as I was at the processors talking to the bloke operating the toughening machine I was able to ask him not to mark it. It's still flat & boring glass though

 

[88v8]

I think during the 30 years we were in our previous house we only broke two windows, one of which was broken by me to gain access when we locked ourselves out on a Sunday.

If we were in the habit of breaking windows, I'd buy a couple of large sheets of 'period' glass and keep them against future need, rather than degrade the aesthetics of the glazing.
The 'period' magic of ye old house can be diluted, drip by drip, and temporary fixes have a habit of becoming permanent. Despite my best intentions.

Ivor

 

[plasticpigeon]

I can't imagine acetone or acid doing much. Acid can etch glass but how can it make it wavy? I bet there is a post processing heat treatment that could make it wavy though. Near me there is a McDonalds burger place that has very ripply glass. I imagine it is the heat treatment to make the glass toughened.

 

[LadyArowana]

Near me there is a McDonalds burger place that has very ripply glass. I imagine it is the heat treatment to make the glass toughened.

Nothing to do with lots of greasy fingers on the windows ?

 

[MatthewC]

I think during the 30 years we were in our previous house we only broke two windows, one of which was broken by me to gain access when we locked ourselves out on a Sunday.

My house had one broken by the police when they broke in to find the previous owner (deceased) - shame they chose to break the largest pane in the house! Then we had one broken by something when we had scaffolding up and then I broke a third whilst splitting a lath very carefully with a Stanely knife, forgetting that the other end was disappearing over my shoulder...

If we were in the habit of breaking windows, I'd buy a couple of large sheets of 'period' glass and keep them against future need, rather than degrade the aesthetics of the glazing.

Where from? When Ventrolla did my neighbour's house, the first thing they did with each window was to break all the glass. :x

 

[Delta]

Mr F, did you ever get around to your acid and glass experiments, and more importantly did it have the desired effect?

Cheers

 

[Feltwell]

Erm, no, it's joined the end of an extremely long list of "must get around to doing that one day" tasks

Still, by the time I get around to doing it, the glass will at least be genuinely old............... :?

 

[Keithj]

Had you thought about dabbling with sodium silicate (waterglass, to those who use it for picking eggs and such rural pursuits)?

We used Beeck paint (silicate based) on our NHL3.5 plinth, and it came with dire warnings about keeping it off the glass.

 

[agbagb]

Grinding then polishing it could give you the optical wobbliness you are after. Diamond pads, grinding pastes and cerium powder on a polishing machine would be fun try.

I'm not sure about the effect on safety glass though, is it through tempered so it shatters in to little pieces rather than shards. If so taking the surface back shouldn't be a problem.

PS. Same grinding and polishing techniques I used to polish my scabby bath. Also will work to polish out sand paper scratches on glass (I seem to remember someone having a problem with a while back)