I have a client who wanted me to do some gold leaf on a glass window. However the glass has a tinted film on the inside so we opted for Sign Gold on the outside. It was a simple job. All vinyl lettering & graphics. The logo is a combination of 3M Oyster & Forest green. The lettering is Forest Green outline with Sign Gold letters. I applied the film on Saturday. This afternoon (Tuesday) she called me, just about in tears. She heard a "pop" and went to check it out. The glass pane had shattered. (The windows are insulated units - the inside glass is unscathed) The storefront is located on a busy street - could have been a rock from a car. It was mid-afternoon on the west side, so it could have been an expansion/contraction problem caused by the difference in the reflectivity of the lettering and the absorbtion of the tinted glass. Unfortunately, the sandblasted sign I did for her a few years ago has twice been vandalized and this was our solution to having to repair this vandalized sign once again. Has anyone ever heard of this happening? I dare not do it again if it was caused by the Sign Gold on tinted glass.
Posted by Checkers (Member # 63) on :
Hiya Dan, It's been discussed here before and it is possible for a graphic applied/painted on a window to cause it to break. Highly unlikely though. Do you have a picture of the design? The reason for asking is that, depending on the design, contrasting colors can cause the glass to expand & contract a different rates, causing the glass to shatter. If I recall correctly, the one situation was a black stripe painted across the center of a window that caused the failure. My bet is that it was either a fluke or the competition may be getting jealous of your clients image.
Havin' fun,
Checkers
Posted by Mike Pipes (Member # 1573) on :
Here's some reading for you.
Yes, it's possible the decals on the windows were the straw that broke the camel's back, but there are other factors that contribute to glass breakage.
If you've never felt a piece of tinted glass that's been sitting in the sun, it gets EXTREMELY HOT.
Posted by Dan Seese (Member # 3705) on :
Thanks Checkers. If I were more conversant with how this bullboard works I'd show you a picture of the design, size on the glass, etc but at this point I haven't figured out how to do it. I'll check the archives to see if I can dig up similar info on this topic from previous posts. Thanks again.
Posted by Dan Seese (Member # 3705) on :
Many thanks to Barb Shortreed for sending me a note about how to post a picture. Now lets see if I can get it to work. This is a digital photo of the window with the lettering superimposed over it in my signmaking program - not a photo of the actual sign on the glass but an accurate portrayal. Maybe the proportion of the lettering and graphics which are somewhat reflective in relation to the dark glass which asorbs heat caused uneven stress. Thanks also to Mike for that link. It, too, confirms that signs on glass can cause breakage. I recall discussing this same issue in a different situation with Kent Smith sometime in the past but it never entered my mind on this job until the glass popped. I've done a lot of window signs - many of them gold leaf where the sun bakes it - and have never run into this before. Anyway, I'm heading off to bed, but thanks for the input and if anyone else has any insight, let me know.
Posted by FranCisco Vargas (Member # 145) on :
Ah come on customer, Sign Gold or any type of vinyl HP or Cal slapped on the window is not going to make that window break. If heat was a factor, it would have broke already. Some bastard broke it and they want to find someone to blame, "yeah it was the sign material applied on it, yeah it's the vinyl guy." He has should pay for it...Not today!
Posted by Dave Draper (Member # 102) on :
Hand painting on large store front windows was a risky business back when I was a newbie. I was cautioned by my mentors never to paint a solid panel over a lagre section of glass facing the sun. The glass would crack along the edge of the stripe.
The windows they were talking about were very large, the glass was probably different back then.
I have those worries to this day, and have done some large windows with big white vinyl panels extending from frame to frame that are facing the South. I placed some intermediate verticle cuts in the vinyl to allow for expansion, and never experienced a break, yet.
I think if the sign caused it, it would crack first, along the panel edges, and the crack would keep extending, like it does in a car windshield when a rock hits it.
I would say nothing! I would just look "aloof" and offer no explanation, just shock. This is very rare, and difficult to point the finger at the exact cause....you do not know that the glass was stressed in the door frame to begin with, or if was a vandalism act, or the window washer man who lost his squeegee and was cleaning bird crap off the window with his hammer!
[ October 15, 2003, 02:26 AM: Message edited by: Dave Draper ]
Posted by BrianTheBrush (Member # 1298) on :
Dan,
The first, obvious question I would have to ask you is, given the relatively small amount of SignGold in that layout, versus the larger, and substantially denser amounts of other materials you used...why would you suggest in the title of your post that it was the SignGold? Just an honest question.
I've found that working on tinted windows with paint or vinyl to have it's risk factors. About 15 years ago, I painted some ice cream parlor windows from the outside, because they were tinted. The design included 24" high x 60" wide solid areas, where I rolled on black paint, followed by burgandy, and then airbrushed in a faux granite effect. (this, times 8 windows). I then lettered them with the various menu items (sundaes,floats, milkshakes, etc). With a week, 3 windows had broken, and myself and a few other painters, as well as a local glaser, decided it was the large, dark areas absorbing the heat, and the tinted areas reflecting it. The glaser refered to it as a "thermal-something or other".
I've also seen countless window jobs with even more coverage, that never had a problem.
So in essance, I have no solution. I can tell you, for whatever future reference, that SignGold blocks utraviolet rays unlike any other material. The Tedlar is a UV blocker in itself, but it's a fact that nothing blocks UV like gold (the element, not the color).
If I can be of any assistance, call me on SignGold's tech line, 585-415-7496, M-F 8-5:30 eastern time.
Hope it all works out.
Brian Briskie
Posted by Tony Vickio (Member # 2265) on :
Seems to me that Sign Gold would actually reflect heat! I can not see it as the fault!
Posted by Ken Henry (Member # 598) on :
I feel that the real cause of the problem is the green panel, and the amount of space that it occupies on the glass surface. Green is one of the most efficient colours for attracting and holding heat. That's why most vegitation is green...to attract and hold energy from the sun, and convert it so that plants can grow. With as much green area as there is, it would attract heat and "localize it" in that given area. The glass would then expand at a different rate than the surrounding glass, with the end result being the glass shattering. Posted by Bill Diaz (Member # 2549) on :
Dan, I have had this happen to me. A good friend of mine owns a glass company and has warned me about this. My problem also occurred on a thermo-pane window, and maybe that's it. In 25 years of lettering windows it's only happened once, but that doesn't diminish the aggravation. You can be sure it's an expansion and contraction problem. My problem was a result of using a panel also, so maybe that's it. Wouldn't it be nice if a chemist could chime in here, it seems like a lot of what we signmakers do is on a trial by error basis. Unfortunately when you do something on a whim and a prayer you can only hope for the best. That's why this board is so important. Sorry and good luck.
Posted by Dan Seese (Member # 3705) on :
Thanks to everyone for your input. I've learned the following: 1. Don't blame SignGold in heading in my post. You don't give the doctor the diagnosis. 2. Don't use a dark panel that is large in proportion to the rest of the glass. 3. Don't worry about not being able to post a photograph because Barb & Steve will come to the rescue. 4. Don't tell the customer it's my fault unless I'm sure of it. This is a rare problem and it's not possible to determine if it was caused by my graphics or by a rock. (Though it was most likely the graphic) At any rate, I'm not going to put it back on the glass. Insurance helps with these situations but I don't need to set myself up for failure. 5. Don't feel alone when a problem happens because there are plenty of other people who have had similar situations and will give you their input. 6. Don't worry, be happy. (that is sooo yesterday) Thanks again. Got work to do.
Posted by Tasmus (Member # 445) on :
How long has that glass been tinted? If the the tint installer used auto tint, on NON TEMPERED glass, that very well could have been the source of the problem. I know from painful experience, had my own store windows tinted by a local guy, only to have them crack down the middle in the morning sun after a chilly fall evening--in just about this time of year.....just a thought. I would definitely find out about that tint job.
b
Posted by Peter Manzolillo (Member # 1062) on :
Way back when I remember hearing, or reading, (in Leblanc's Gold Leaf book, perhaps?) that black should be avoided on windows, especially large black panels, because it will absorb heat and possibly cause the glass to crack.
The alternative was to use Cobalt Blue japan paint, which is very dark and appears black when viewed from outside...
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