Question Does Museum Glass Expire?

[i-m-chickie]

I was just talking to a friend of mine in UK, who also is a regular customer when she stays here in the states. She gets framing done here and also shares a great passion for needlework.
I have recently been bowled over by Museum glass, neat stuff. Pricey, pickie, the source of angsty threads here on the grumble....well I like it.
My friend just spent the weekend in Hampton Court for a visit to the Royal School of Needlework (makes me green, needlework heaven). Anyhow she got into a conversation withthe curator of the RSN about museum glass. Discussing how bright, clear, polished...bells and whistles...cost too, of course, yikes, they spoke of a large piece they had done with museum glass 900 pounds worth.

But, my friend then said,'do you really have to replace it every ten years ?' "huh?" says I. Did I miss something. She said something about a film between two sheets of glass wearing out and turning greening in around ten years. At the price point that it is offered is that correct? If it isn't I think the Royal School of Needlework should know...at least enough to stop scaring my customers.
Thoughts...
Cathy

I know yet another thread about museum glass

 

[FramerDave]

Short answer, no.

Museum Glass, at least the trademarked variety from TruVue has never been made with a film between two lites of glass. Perhaps she is thinking of a different product?

 

[i-m-chickie]

Never Mind!

I googled it.
I read Tru Vue's web site.
I called Tue Vue.

It's Rubbish. It does not expire.

End of thread.

 

[i-m-chickie]

Thanks for replying tho' Dave. You probably typed as I chatted with tech support. The product is in the glass not between the glass.
Appreciate your pennies.
Cath

 

[CAframer]

BTW there is additional discussion on this subject here

 

[Rob Smith]

Short answer, no.

Museum Glass, at least the trademarked variety from TruVue has never been made with a film between two lites of glass. Perhaps she is thinking of a different product?

there used to be a glass like that forget who made it. real pain to work with.

 

[RoboFramer]

The ROYAL School of Needlework - sounds great, doesn't it!

Well here's a photo of a piece I re-framed from a RSN diploma course - more here. (Clickable images)

 

[Jim Miller]

The product is in the glass not between the glass.

The glass you described is laminated glass, which often has a UV-filtering element between the sheets. I've not heard of UV filter deterioration with that sort of technology. Maybe your partner in conversation might have been misinformed.

Museum Glass is not laminated. It is a single sheet with optical coatings on both sides. Actually, the UV filtering comes from a third coating applied over the optical coating on one side of the glass.

Museum Optium Acrylic has the UV filter in the sheet, and it also has the two optical coatings.

 

[GhostFramer]

Goofy Brits!

 

[Bill Henry-]

I googled it.
I read Tru Vue's web site.
I called Tue Vue.

It's Rubbish. It does not expire.

End of thread.

Maybe. The general consensus says that that the UV laminate doesn’t lose its effectiveness over time. But, despite three e-mails, TruVue will not release their testing results (the testing was done in house and not by an independent testing lab). In a more-or-less form letter, they state that “under normal field conditions” that they have noticed no changes. But, again, they refuse to state what those “normal” conditions are.

I’m not willing simply to take their word for it and simply echo their claims.

Flabeg (a European manufacturer of a similar product) also will not disclose their testing procedures nor will they divulge their results.

So … maybe.

 

[Terry Scidmore CPF]

OK, I know everyone is sick of hearing from me, and I am not a scientist, or even that smart, but looking into UV glass over the years, these are some points I've picked up - including from TV:


7)My understanding from TV when they tested my glass sampler is the filter longevity is tested over a period of time on sample lights of glass. If the filter still filters the advertised rate, then the filter is still "operating". Hence, the longevity is "unknown", and is being tested as time goes by. I think the filter will probably last a long time based on what I have read - probably longer than the art.

My apologies if I've offended anyone in posting this. I'm not bashing TV - they have been a good company in many ways. I sell TV products. I just make sure my customers are aware of point #4 in particular.

 

[Kirstie]

Thanks for replying tho' Dave. You probably typed as I chatted with tech support. The product is in the glass not between the glass.
Appreciate your pennies.
Cath

If you ever have a TruVue sales rep in your shop you might get to see the magnetron sputtering display. Fascinating!

 

[Kirstie]

The glass you described is laminated glass, which often has a UV-filtering element between the sheets. I've not heard of UV filter deterioration with that sort of technology. Maybe your partner in conversation might have been misinformed.

Museum Glass is not laminated. It is a single sheet with optical coatings on both sides. Actually, the UV filtering comes from a third coating applied over the optical coating on one side of the glass.

Museum Optium Acrylic has the UV filter in the sheet, and it also has the two optical coatings.

We were told by the national sales manager that all MG starts as Conservation Clear. Then it goes through the magnetron sputtering device. Given this, then wouldn't MG hold up as well as CC?

 

[Jim Miller]

...despite three e-mails, TruVue will not release their testing results...
...I’m not willing simply to take their word for it and simply echo their claims.

Bill, have you ever heard of a credible claim that the UV filtering ability of a glass or acrylic product has diminished?

To my knowledge, every manufacturer of UV filtering glass or acrylic claims the filtering ability is permanent and will not diminish appreciably over time. Do you have any reason to doubt the claim, which seems to be universal?

I guess "normal" conditions could be speculated, but it has been established that conditions of extreme heat and moisture could degrade the coatings or laminates. So it would be advisable to replace the UV-filtering glazing after exposure to, say, a house fire.

A framer I know theorized that when fading shows up over a period of years, and the owner finally notices it, their assumption is that it happened only recently. But in reality, it happened gradually over the entire time the framed art was exposed to light.

We all know why UV-filtering does not stop fading, right?

 

[Bill Henry-]

Jim,

I have no credible evidence or even suggestion that the claims by the glass manufacturers are false or distorted. But, the fact that they will not release their own testing results makes me less than confident to simply pass along their claims.

I spent a fair amount of time on line trying to determine how UV Absorbers worked. Most of the articles I read said that UVA polymers are “sacrificial” i.e. as they absorbed UV rays, convert them to heat, and in so doing, they change chemically and are eventually “consumed” and rendered less effective over time.

Les (RealHotGlass) states that the chemistry in those UV films is somehow different, but I cannot determine how they are different without TruVue’s help.

The makers of Vista UVShield Window Film, for example, recommend that the effectiveness of their product be tested after three years and replaced every ten years of so. They do not make the film that TruVue uses, so I do not know how it is different – or, in fact, IF it is different.

But, that is just the point. I don’t know.

I am fully aware that the visible light can also fade materials, but TruVue doesn’t make any claims for that part of the spectrum I don’t believe. I am simply questioning their claims of the longevity of its UV protection.

Until, TruVue can back up their claims of the permanence of its UV protection film, I will continue to be as skeptical as I am with a used car salesman.

 

[Cliff Wilson]

My guess is ... if there was any evidence that it degraded they'd be making sure all of us knew that!

Sales would be increased sales through replacement!

They would have every incentive in the world to be telling us it degraded if they had any evidence that it did.

 

[Jim Miller]

We were told by the national sales manager that all MG starts as Conservation Clear. Then it goes through the magnetron sputtering device. Given this, then wouldn't MG hold up as well as CC?

We may be on the lunatic fringes of glazing technology here, discussing such fine points of manufacturing, but I think there's a misunderstanding to be corrected.

AR, MG, and CC all start out as plain, low-iron glass. The optical coatings are applied to both sides first, making AR Glass. Then, the UV coating goes on top of the optical coating on one side, to make Museum Glass. CC has only the UV coating on one side.

On both CC and MG, you can find the side with the softer UV-coating by scratching with a blade in a corner where it would be hidden under the rabbet.

 

[Jim Miller]

...They would have every incentive in the world to be telling us it degraded if they had any evidence that it did.

What a great point of logic, Cliff!

 

[Bill Henry-]

My guess is ... if there was any evidence that it degraded they'd be making sure all of us knew that!

Sales would be increased sales through replacement!

It’s difficult to say since I’m not a marketing expert, but it would seem to me that TruVue’s stating, “Our CC is great out of the box, but in five years … well, not so much!”, wouldn’t get them nominated for a Clio award.

I think we could argue both ways, but my take on it is if people didn’t believe that CC or MG would last a while, why would they buy it to begin with instead of clear light?

Again, I just don’t know, but I wish that TruVue would be a little more forthcoming and back up their claims with some evidence.

 

[BILL WARD]

have to replace it every ten years


enterprising tradesman!!!!!!!!!!!!!!!! or heck of a scam artist-depends on which side of the counter you're on?

absolutely HAVE to remember this one----don't think every 5 years sounds toooo good as far as 'reliable', so guess we should stick with 10 years---has a nice ring to it, yes?

 

[Bill Henry-]

----don't think every 5 years sounds toooo good as far as 'reliable', so guess we should stick with 10 years---has a nice ring to it, yes?

Maybe we should state eight years and three months just to make it sound more 'scientific'?

 

[wpfay]

Would you like to buy our extended warranty with that?

 

[Jim Miller]

Competitive edge:

His glas is good for only ten years? Ah Ha!

My glass is good for lifetimes. See? Here's the manufaturer's claim...

 

[i-m-chickie]

If you ever have a TruVue sales rep in your shop you might get to see the magnetron sputtering display. Fascinating!

I am too small a shop to nearly ever get a sales call...some of you complain about sales calls...my LJ rep is a phone call; he's fabulous (i mean it Damien if you're reading this) but I don't get sales calls, who sales calls a needlework shop with 130 square feet of corner samples and a very tenacious, obnoxious, opinionated blonde in it.
They have a megatron!!!
Watch this space!!!
Thanks for the info folks...this tenacious, opinionated, obnoxious blonde is listening....
Cathy

Oh, BTW Roboframer you really reframed a piece for Royal School...I want to buy you dinner man!!!

 

[i-m-chickie]

I am too small a shop to nearly ever get a sales call...some of you complain about sales calls...my LJ rep is a phone call; he's fabulous (i mean it Damien if you're reading this) but I don't get sales calls, who sales calls a needlework shop with 130 square feet of corner samples and a very tenacious, obnoxious, opinionated blonde in it.
They have a megatron!!!
Watch this space!!!
Thanks for the info folks...this tenacious, opinionated, obnoxious blonde is listening....
Cathy

Oh, BTW Roboframer you really reframed a piece for Royal School...I want to buy you dinner man!!!

Oops1 Blonde moment! you said magnetron...hee hee...not megatron..... OMG!!!