Safe sizes for glass

[RoboFramer]

Amazing how posts here remind me of questions I have raised in the UK - pre-grumble - not got a satisfactory reply and adopted my own SOPs.

Before I continue I must apologise for the use of metric - it's just how UK suppliers do it. Standard is 2mm - some UV or coated glass is 2.5mm.

If I have a large piece I can go to 3mm or beyond, and there is also acrylic of course. I stock acrylic but it's dearer than 3mm + glass, which I will buy cut-to-size. Don't want stock of large sheets of glass. Oh, and I only use scratchproof acrylic, which makes it dearer still than thicker glass.

When I asked our Fine Art Trade Guild, they said one square metre (39.4" x 39.4" just under 11 sq ft) - was safe for 2mm glass - depending on what you BACKED the piece with. They were thinking art against the glass - backing ditto. I replied "NO - NO .... NOTHING behind the glass - artwork spaced, say half an inch FROM the glass - what is safe?"

No reply

Long time ago, and as I said - have adopted my own S.O.P.s - which are basically imagining the o/a glass size and thinking 'NOPE' - don't wanna do it in 2mm!

What is the largest you would do in the thinnest glass you use - assuming art spaced from it?

[froptop]

I stock 32"x40" in 2 ml and 36x48 in 2.5 ml. So, any piece over 32x40 is 2.5 in my shop.

[RoboFramer]

Should have added that I buy 2mm glass 36" x 48" - in fact that's the standard here default - UV - Museum - I never buy smaller and if I want larger I'll have it cut to order.

[Bill Henry-]

I don’t know whether it is a regional or national thing, but like froptop I get 2 mm up to 32 x 40 and 2.5 in anything larger than that.

I’ve never seen/used glass as thick as 3 mm. I would be worried about weight. I wish 40 x 60 came in 2 mm thickness.

I generally order custom cut glass for sizes above 48" and all I can get is SSB which, I believe, is 2.5 mm.

[RoboFramer]

Wow!

I don't think there is such a thing as standard 2.5mm paper float here. It goes 2mm then 3mm. The only 2.5mm I have seen has been coated - e.g. WW Denglas - and it's probably the coatings, each side, that have made the extra thickness!

After that I don't know - I've always gone 'Artshield' (3mm scratchproof acrylic) - in fact I'll usually talk the customer into that instead of 3mm+ glass anyway due to the weight factor.

My glass supplier will supply laminated and toughened glass up to 6mm - never had a call for it yet - apparently the laminate is a very good, even if unintentional UV filter! - Weighs a ton though!

I have cut 4mm and 6mm glass, but silvered (mirror) - so - if a mirror a certain size has to be a certain thickness - why not glass? It's still glass!

There are regulations for window glass - especially (at least in this country) if it is in a door - e.g. if our shop door panels at the BOTTOM were glass, they would basically, have to be bulletproof or have wire runnning through them, as well as being safety glass!

But no regulations for something hanging on the landing by two hooks, probably installed by a DIY-er that could fall and decapitate you!

[JFeig]

John I found this chart - note the nominal sizes vs minimum sizes.

http://www.iwfa.com/iwfa/member_services/failure8.html

I agree that SSB is what most of us use. It is 2.5mm thick(nominal size), but can actually be only 2.2mm thick if you actually measure it with a micrometer. It varies as what the distributor purchases from the glass mills. Since 2mm is cheaper, many suppliers sell that size. A 2mm lite of glass can actually be only 1.8mm thck. Remember that glass at the mill (manufacturer) is sold be weight and not sq. area.

I also agree that 40 x 60 is my limit. Remember also that double strength glass is not double the thickness.

It is all the same measurement theory as buying a wood 2" x 4" stud. Measure it and it does not measure 2" x 4"

[5th corner]

Hey all

Back again and in a new job in Idaho.

I had an issue today of a piece 30 x40 limited ed print small triangle frame with large fillet.

Museum glass was the solution. How many framer would have used plexi in this situation. If using museum would you have given option for plexi?

Why would you use plexi over glass. Boss says no one on west coast uses plexi????

Interested in your responses

[CAframer]

Normally anything over 36x48 gets acrylic, although on occasion I will use glass up to 40x60. And BTW 5th corner, I am on the left coast!