quick poll of opinion - styrene (acrylic) and conservation

kev@frames · Post by **kev@frames** » Sat 10 Mar, 2007 2:29 pm

quick poll for a second opinion- standard styrene acrylic - better or worse than 2mm float? UV blocking acrylic, better or worse than UV blocking glass?

purely from the viewpoint that my customer needs to ship a lot by carrier, the frames / mounts /etc themselves are to be "conservation" standard by FATG guidelines. and glass is not an option.

just seeking a second opinion over the weekend, any big point i may have missed re acrylic glazing?

cheers
Kev

realhotglass · Post by **realhotglass** » Sun 11 Mar, 2007 5:18 am

Does Conservation grade there = automatic UV glass ?
By many Aussie standards it doesn't, normal glass can be used.

If the same there, then I assume regular acrylic would be fine, it would block considerably more UVA than 2mm float.

Another option you may have is Plexiglas MAR acrylic,
You can rub this stuff with steel wool and not scratch it, 99.8% UV blocking.
It is pricey though.

markw · Post by **markw** » Sun 11 Mar, 2007 8:22 am

Glass and mirror have lots of choices for plastics - their website is fairly good http://glassandmirror.co.uk/. I think the scratch resistant stuff has to be cut on a saw.

Roboframer · Post by **Roboframer** » Sun 11 Mar, 2007 9:13 am

'Artshield' is G&M's scratchproof acrylic - comes with a UV filter.

They say saw it but I score and snap it with the scoring blade on my excalibur - it wrecks the blade each time but what the hec!

kev@frames · Post by **kev@frames** » Sun 11 Mar, 2007 9:21 pm

thanks for the help, everyone.

realhotglass- i didn't appreciate that acrylic blocked more UV than clear float! Yup, I think the australian version of conservation is pretty much same as here (or should it be preservation - or damage limitation lol)

Robo- I also stopped cutting plastic ages ago on the s4000 (thats the older version of the excalibur) I never managed to get more than a couple of cuts before the blade was finished. We always use a metal straight edge and a proper scoring knife now, with one of those hooked blades that looks like a "lino" knife.

Now that I think about it, one of those "lino" blades would probably fit into a 4000/excalibur turret, and they last for ever. You'd lose your board cutting blade on the other side, though...

beth · Post by **beth** » Wed 14 Mar, 2007 5:46 pm

Art shield UV coated is great stuff, and oversized valuable work prefer it to 3mm glass. I get it cut to size to save time and wastage and if I am feeling lazy I gat the backing cut as well all from glass and mirror

Not your average framer · Wed 14 Mar, 2007 8:26 pm

kev@frames wrote:
I didn't appreciate that acrylic blocked more UV than clear float!

Kev,

I've been led to understand that all clear acrylic has an inherent UV blocking characteristic, although it's difficult to get the info to back this up.

I always heatseal the open-edition prints which I'm going to put in the shop window so that they don't fade. This is because the Hot Press heatseal films include an acrylic adhesive, I imagine most others would be the same.

Roboframer · Post by **Roboframer** » Wed 14 Mar, 2007 8:37 pm

I haven't used any acrylic but artshield for years, my experience was that all the 'normal' stuff went fuzzy after a few wipes, regardless of what I used to clean it.

Still the case?

Don't nornally want to know about great lumps of heavy glass either, so Artshield it is!!

Oh - safety glass (or is it toughened? - the one with a central membrane anyway - has to be 'burnt' to cut it) has a very good but unintentional UV filter - can't remember what % but it's high.

One rep told me a story about a framer that advertised normal non-reflective glass as blocking '45.35% of UV light' He wasn't lying, BUT....

Normal clear glass blocks 48%!!

(Figures may not be accurate)

kev@frames · Post by **kev@frames** » Wed 14 Mar, 2007 10:35 pm

hi Robo. yes the "regular" styrene is quite easily marked. I never see it as a "quality" option, more of a health and safety option when we provide frames going into schools, cinemas, pubs etc.

Roboframer · Post by **Roboframer** » Wed 14 Mar, 2007 10:54 pm

kev@frames wrote:
Now that I think about it, one of those "lino" blades would probably fit into a 4000/excalibur turret, and they last for ever. You'd lose your board cutting blade on the other side, though...

Not on the Excalibur - two separate blades - I will order some of those viscous things on my next Lion order - thanks.

Lemon_Drop · Post by **Lemon_Drop** » Wed 14 Mar, 2007 11:20 pm

Theres a differance between the 2 types of glass John.

The one with the membrane that you burn is laminated, its 2 sheets of glass with a plastic film in the center, the easiest way to cut it is score both sides and run methylated spirits onto the score line and set fire to it.

Toughtened glass is different. Its cut to size first and then heat treated to make it stronger.
Once its toughtened it can never be cut again. So you can't go out a buy a crate if it. If you try and cut it it will shatter into small pieces. Its mostly used for door panels and glass table tops.

The toughtened glass when it breaks, shatters like th windscreen of a car, but the laminated will crack and plastic film will hold the broken pieced together.

I cant see many framers using toughtened glass unless they are near a glass company thats got a treatment furnace.
Laminated glass maybe or some use.

Both types use float glass in thickness ranging from 2, 3, 4, 5, 6, 8, 10, 12, 15, 19 and 22 mm also.

Roboframer · Post by **Roboframer** » Wed 14 Mar, 2007 11:55 pm

Lemon_Drop wrote:
Toughtened glass is different. Its cut to size first and then heat treated to make it stronger.
Once its toughtened it can never be cut again. So you can't go out a buy a crate if it. If you try and cut it it will shatter into small pieces. Its mostly used for door panels and glass table tops.

........... and chopping boards! We had a glass chopping board with rubber bumpers - God we hated it! When we decided to out it I took it down the workshop to see what happened if I tried to score and snap it ....

The toughtened glass when it breaks, shatters like th windscreen of a car

Yep!

realhotglass · Post by **realhotglass** » Thu 15 Mar, 2007 2:54 am

Further . . .

Laminated isn't avalaible generally in useful thicknesses for framing, 5.38mm & 6.38mm weighs a fair bit.
Colour is then a real issue, with the usual green-ish hue to it, the thicker (6mm) body of glass would be quite distinctive and annoying on most colours, particularly lighter tones and especially whites.

Now, a few specialty manufacturers make 4.38mm with low iron glass, reflection free optical coatings, and they are just brilliant, still a bit weighty, but much more bearable and safer / more protective on large works.

The laminated PVB interlayer does block 98% of UVA, which is the main one framers have to stop.

Normal glass will vary on amount of UV blocked.
2mm float (with avg iron content, ie the green-ish hue) will block about 20 - 25%, low iron a lot less, maybe only 10%, 3mm goes up to about 35 - 40% blocked, depends on each batch and iron content.
Thicker regular float glass blocks more UV, but is worse in appearance / discolouration..

As far as I know, toughened is only done in Australia from 4mm thickness up, unless using low iron will still have the green hue issue, must be sized / can't be cut (as pointed out by Lemon_Drop), has minimum size requirements (here it's 350mm or so minimum diagonal but can vary), generally long lead times, and usually has a wavy appearance like old sheet drawn glass.

Toughened has similar UV blocking to that of plain glass in the same thickness, so really not a glass that would be considered for framing for practical reasons.

Sorry

I'm a bit of a glass nut !