properties of plate glass

Matt@ · 3 Jan 2012

Hi, I need to use 4mm plate glass to cover a 54" diameter antique table top in order to protect the polished surface. I can order this cut to size and polished and need really to use toughened as lying the glass flat on the table top will create "hollows" beneath the glass where there are slight undulations in the wood. Got two dilemmas with this

1. Is toughened 4mm plate glass slightly non clear/ distorted (if that makes sense) due to the toughening process and if so how much clarity is lost

2. If the table top is very slightly twisted, I'm concerned the glass will not sit dead flat and will rock. On a 54" span of 4mm glass is there any flex? ie couple of mm across its width or does the glass stay dead flat.

I'm knowledgable about wood but clueless about glass :?

paultnl · 3 Jan 2012

My 74" rosewood table came with a glass protector that the previous owner had made. Not had any of the issues that you are woried about.

jasonB · 4 Jan 2012

Its unlikely to distort the pattern of the wood but may give it a slight greenish tinge, if thats an issue get Low Ion glass, Pilkington call it Optiwhite.

You will get slight flexing on 4mm of that size but if there is a lot of cupping of the table it won't take it all up.

J

Matt@ · 5 Jan 2012

thanks for replies - I'll go for it and cross fingers!

Jacob · 6 Jan 2012

Tell your glass supplier what you want it for.
There are a whole range of "toughened" glasses some of which aren't all that tough but are "safe" in that they break into non sharp crumbs like car windows. Others are very strong and can be used structurally for floors etc.
As a rule they are cut to size, drilled etc before undergoing toughening processes.
There are also laminated glasses but I don't think that is what you want but I don't really know, it's a specialist area.
Your glass supplier will advise you.

http://en.wikipedia.org/wiki/Architectural_glass