posted
While at a dinner party last night, an architect called and wants to me with me at a project site early this morning. His client (who is a regular customer of ours) wants to have their logo added to the outside of a new glass vestibule that links two of his buildings together.
Naturally, no one thought to do the graphics before the glass was installed.
The architect is thinking window-perf or etch-vinyl. Knowing the client like I do, neither are going to be acceptable. He's going to want something permanent.
The glass is tempered so sandblasting is out.
I'm thinking acid etching but the graphics are going to be about 5' tall, done on a vertical surface and in the cold.
posted
It can be sandblasted even though it is tempered, but is it already installed to where blasting is not possible?
I have surface frosted many of tempered pieces in the 30 years that I have been etching. The two main steps are, #1 Surface frost only. (no cutting deep)
#2 You need to make sure the temperature does not fluctuate. The glass needs to be in a good warm room and you need to keep moving on the blasting (do not let it heat up).
The glass being tempered is like shrink wrapping on a boat for storage. It is under a lot of tension. You can scratch on it all you want, but if you keep scratching it in the same spot (as in cutting to deep) it will get week and the tension is going to take over and pull it apart or as in glass explode into small pieces.
Yeah I know this for a fact!
But again, if you have the area to blast, then putting a nice frost on it is going to look a lot nicer than an acid will do.
I have done salad bar sneeze guards, Club House shower doors & condominium glass doors and in all my years I have only had two break.
1. cutting to deep (plus it was under vacuum).
2. blasting outdoors in cooler weather. The heating temps changed and POW! your starting over.
When I know in advance, all my pieces are carved to multiple depths and then sent in to be tempered after I am done.
I hope this helps some. Glass has been a lot of fun for me over the years.
-------------------- Sam Staffan Mackinaw Art & Sign 721 S. Nokomis St. Mackinaw City, MI dstaffan@sbcglobal.net Posts: 1694 | From: Mackinaw City, MI | Registered: Mar 2004
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posted
I'll agree with Sam's advice. I'm not sure acid etching will provide enough of a uniform appearance. However sandblasting can, when done properly. Might be worth doing an in shop sample.
If you've never done on-site sandblasting, give it some thought. It's quite a bit more work to haul and set up all the equipment. If you don't have a vacuum blaster (a unit that recovers the media right after etching the glass), you may need to tent the area to control the media and the dust.
Another problem I have seen is individuals not have the proper equipment. Most, compressors that don't deliver enough CFM to keep up with the blasting. Also, trying to get a large area blasted uniformly with too small of a nozzle.
Also, be sure to use the right masking material. For a surface etch, I like to use Venture Tape 4mil white sandblast resist. It cuts easily and is easily removed after blasting with no glue residue.
I have found that on-site sandblasting is more trouble than it's worth and I no longer offer that service. Also due to insurance reasons, and some jobs sites want you to have a contractors license. Doing it on-site also becomes a bit of a "side show"...and that always makes me a bit nervous.
The job would be worth some bucks, and due to the time and amount of work, be sure to charge accordingly. For the on-site work I have done, it's 4-5 times more expensive that doing it in the shop.
Hope that helps, and , good luck, heh!
-Larry
-------------------- Larry White Town of Machine www.walljewelry.com whitel@iname.com Posts: 36 | From: Machine | Registered: Jul 2003
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posted
Light blasting with 220 aluminum oxide using calendared vinyl for a stencil. Alot of glass companies have a portable rig with a built in vaccuum for etching on site.
[ December 22, 2009, 11:12 AM: Message edited by: John Byrd ]
-------------------- John Byrd Ball Ground, Georgia 770-735-6874 http://johnbyrddesign.com so happy I gotta sit on both my hands to keep from wavin' at everybody! Posts: 741 | From: Ball Ground, Georgia, USA | Registered: May 1999
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posted
I agree with the aluminum oxide being used and although in the past have used it, I'm wondering what amount of pressure as well as what gun. Gotta be bigger than an Air Eraser for that amount of space
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
posted
Last time I did something indoors was for a high rise office building. We did the stencil and applied and the glass company did the etch. The rig looked like an oversized vaccuum cleaner (here's one -do a search for uniram-dustfree-abrasive-blaster-and-vacuum-model-ur007y ). The gun was a standard suction type gun inside the nozzle of the vaccuum. One of those hairy looking attachments your Grandma would've had. The only problem was that you couldn't see what you were doing because the big round 'brush' was in contact with the glass while you pulled the trigger on the gun. You'd blast a little and stop and see your progress. Not the best way to go about it but no mess. When I do a job with the aluminum oxide I use the syphon/suction gun with tthe hose dropped into the bucket of abrasive and shoot at about 80 p.s.i. but I'm not right up on top of the glass. The better suppliers would be good for more information or like I said, find a glass company that does this sort of thing.
[ December 22, 2009, 04:13 PM: Message edited by: John Byrd ]
-------------------- John Byrd Ball Ground, Georgia 770-735-6874 http://johnbyrddesign.com so happy I gotta sit on both my hands to keep from wavin' at everybody! Posts: 741 | From: Ball Ground, Georgia, USA | Registered: May 1999
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I met with the owner yesterday morning. Since the architect was running late the owner walked me through the project showing me what he wanted done.
The glass is some sort of high-dollar thermal stuff. He was pretty proud of it and really wanted to dress it up.
Meanwhile, I just started seeing one flag after another.
For one, he wants the project done within two weeks. Second, he wants the pattern blasted on the interior side all while having to work around painters and cabinet installers and their schedules.
I turned the job down. I've blasted tempered glass before and ended up shattering it every time no matter how careful I tried to be. I don't want to be responsible for it. I even said so and he something to the effect that I could let my insurance cover the damages if I did.
No. I don't want the responsibility nor the risks.
I found out last night that they had already contacted two other companies and they turned it down as well.
Anyhow, the architect just called and asked that if we went with frosted vinyl in the interior side of the glass, would that possible. So, I think that is what we're going to go with. I've quoted $4k for the project done in vinyl since I'll have to do it during the course of several days in the middle of the night when no one is in the way.
Again, thanks for everyone's input. I really appreciate it.
posted
Glenn, frosted vinyl looks almost believable on the inside (if you're not a sign guy that is) but not believable at all on the outside.
You were smart to duck blasting tempered glass. My several attempts turned one large piece into about a thousand little pieces. Fred Self from OKC has gotten away with it on vehicle windows, but he's the only one I know.
-------------------- Eric Elmgren ericsignguy@comcast.net A & E Graphic Signs Park Ridge, IL "The future isn't what it used to be" -Yogi Berra Posts: 192 | From: PARK RIDGE, ILLINOIS | Registered: Aug 2009
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posted
That's interesting, I sandblast tempered glass all the time, and it's very rare for it to break on me. I even sandblast 1/8" tempered. That's a bit scarey, cause if something is going to break, it'll be the 1/8". On most of the 1/4" tempered I do, I blast with either 220 aluminum oxide, or 100 mesh silica sand at about 60 psi. The coarser the grit the more risk of breakage. When I say I'm sandblasting it, it's not depth carved, just a surface etching. Tempered will break more easily than standard annealed glass. I'm just kind of curious as to which factor it is that is causing your tempered glass to break. What do you suspect is the problem?
-------------------- Larry White Town of Machine www.walljewelry.com whitel@iname.com Posts: 36 | From: Machine | Registered: Jul 2003
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posted
32 years provided custom glass etching on various projects. Three years ago, my largest and most profitable project. 118 tempered glass panels for a new sky box at a Nascar track.
Sam is 100% on track. Don't even think of depth carving - asking for problems. And if possible stay away from the edges as that is where the most stress is located.
Just completed a 24" x 36" 1/4" tempered glass panel for the A.I. DuPont Elementary School principal's office door. And was the most detailed design that I've done in 32 years. Vinyl etching would not have been practical due to the extremely small pieces.
Having said my peace, you had to make the decision based on all the steps and cost involved.
Good Luck,
-------------------- Steve Carter {:{) a Touch of Glass 254 Lexington Mill Rd. Magnolia, DE, 19962 PH: 302-335-3170 Posts: 181 | From: Magnolia, De, USA - Center of the Universe | Registered: Jan 1999
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posted
Larry White uses the key words here: The coarser the grit the more risk of breakage.
I find that the choice material for etching any glass is Aluminum Oxide. In the past I've done both etching and carving and have always used the correct tools and materials for the best results.
I think some persons more or less misuse words figuring the results will be the same although there is a huge difference between carving, etching and surface etching and as for surface etching, that would best be used on vehicle glass using aluminum oxide and an air eraser so it can be fogged as well as covered
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
posted
Larry, the glass was 1/4", I use 180 grit aluminum oxide and 35-40 psi. I was experimenting on myself first rather than on my customers, so no big loss. First one was to be a frosted bkgrd, it blew after about 5 minutes, then tried frosted detail, got almost done, tried one more piece. Strike 3.
Joey, I thought frosting, etching and surface etching were the same.
-------------------- Eric Elmgren ericsignguy@comcast.net A & E Graphic Signs Park Ridge, IL "The future isn't what it used to be" -Yogi Berra Posts: 192 | From: PARK RIDGE, ILLINOIS | Registered: Aug 2009
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posted
Eric, maybe you should look into a different brand of vinyl. I have some etch vinyl on my own door at my shop and it is so close to real etched glass that you have to feel it to tell the difference. And, yes it's on the viewing side. Larry White is the most respected glass guy I know, you can trust what he says. You might be blasting too deep, 180 IS too course, you may have the nozzle too close. Another one is Sam. If he says it can be done, it can. You have to be doing something wrong. I've blasted a lot of glass, none tempered though, but I'd do it without worry. (Not Glenn's job though.)
-------------------- Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 sherwoodsign@sbcglobal.net Posts: 5396 | From: Crystal Falls, MI USA | Registered: Apr 1999
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posted
My friend Larry White called my attention to this discussion on blasting tempered glass. I have done nearly everything that can be done to all types of glass and for all types of applications encompasing needs here on earth, to requirements for Nasa. There is no mystery to why your glass is breaking. There is an answer, but all of information of how you are going about blasting your glass must be disclosed. The problem is either with your knowledge of sandblasting glass, or the physical properties of the glass you are blasting. It is breaking ONLY because something is being taken for granted, and that is the root of your problem. If you want to have me review where your problem lies you can call me at 626-359-0300
-------------------- Patrick Mackle Decorative Glass Processes 239 W. Maple Ave. monrovia, Ca. 91016 Posts: 4 | From: Monrovia, Ca. | Registered: Feb 2008
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It is a bit hard to diagnose a problem without every scrap of information. Pat's probably the best sandblasting detective I know.
As for me, I'm blasting with a half inch nozzle, which is really more like 5/8" by now. I run a 375 CFM Diesel compressor, which yields plenty of air volume. At 60psi, I'll do the initial frosting at about 15" away from the glass, then back up to blend it all out. With this set-up I can blast a 4' x 8' panel in about 20 minutes. The 5 sack pot (500lbs.) will last about an hour. My fee to sandblast and seal coat their glass (a 4' x 8' panel), would run $300. Delivered and picked up from my shop.
-------------------- Larry White Town of Machine www.walljewelry.com whitel@iname.com Posts: 36 | From: Machine | Registered: Jul 2003
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posted
"Eloquent Mr. Mackle, but unconvincing..." You are correct Larry, my goal in answering on here is to educate rather than convince. I could convince someone to buy a high mileage worn out troublesome vehicle, but if I educate them on buying used vehicles, they will be much further ahead. Aho, Pat
-------------------- Patrick Mackle Decorative Glass Processes 239 W. Maple Ave. monrovia, Ca. 91016 Posts: 4 | From: Monrovia, Ca. | Registered: Feb 2008
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posted
"Actually I think you have to grind and course the glass first, then make it firehardened."
Yes, this can be done but you should know that tempering the glass after you have etched it can also be problematic. Your glass may break while being tempered and most tempering is done "at customer's risk". They may scratch your glass or chip it during handling. You may be required to deliver your glass to the tempering location and pick it up afterwards which you should plan for in your job quote. I always order my glass with polished edges, mounting holes, and tempered from the factory ready to etch. That way the customer can send their truck their truck to pick it up, and I don't have to load the glass onto my truck at all. That method really saves time and money. Also, if I am going to use the sand blasting mask still further after the glass has been etched, let's say to add multiple paint colors or gold leaf it can be easily done without having to remask after tempering. Pat
-------------------- Patrick Mackle Decorative Glass Processes 239 W. Maple Ave. monrovia, Ca. 91016 Posts: 4 | From: Monrovia, Ca. | Registered: Feb 2008
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quote:Originally posted by Eric Elmgren: I was experimenting on myself first rather than on my customer.
Yeah, Eric, your customers would have gotten a real (blast) out of that! Hate to pun-ish you for the comment.
Reminds me of the guy who taught me commercial painting. He told me about a guy who used to work for him. They were sandblasting a grain bin and the guy was impressed with how the blaster removed all the old paint. He looked down at his boots and said something like "I wonder how quick this blaster will remove the paint on my boots."
He gave it a shot and broke all the toes on his foot.
[ December 30, 2009, 09:42 AM: Message edited by: Bill Diaz ]
-------------------- Bill Diaz Diaz Sign Art Pontiac IL www.diazsignart.com Posts: 2107 | From: Pontiac, IL | Registered: Dec 2001
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posted
You could blast a regular piece of glass and then mount it to the inside of the window. You would have to make sure there was some way to remove and clean it easily. But at least you could still have the look without messing with the tempered glass.
quote:Originally posted by Glenn Taylor: the graphics are going to be about 5' tall, done on a vertical surface and in the cold.
I'm not really sure what "in the cold" means there, but for me this would be the deal killer. If your dealing with cold temps and tempered glass, the heat fluctuations caused by blasting is going to considerably magnify the chance of breakage.
-------------------- “Did you ever stop to think, and forget to start again?” -Winnie the Pooh & A.A. Milne
Kelly Thorson Kel-T-Grafix 801 Main St. Holdfast, SK S0G 2H0 ktg@sasktel.net Posts: 5496 | From: Penzance, Saskatchewan | Registered: May 2002
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posted
Not that I am all that knowledgable on tempered glass I can add one of my experiences with blasting it. Back in the van craze of the 80's I did a lot of glass etching. I did a somewhat extensive design on an aftermarket bay window, it was done with low pressure and fine aluminum oxide through a spraygun type of blaster. I just blasted enough to get a fine frosting.
A few days later the customer called me to inform me that the window exploded while parked in the driveway. I assumed they did something to break it and was hoping to get me to pay for their calamity, so I called a friend who owns a glass shop to do some research. He informed me that he thought it was quite possible that the glass broke from temerature exteremes such as partially shaded in the hot sun after the blasting.
As there was no way to prove how it happened, I redid the job for free, but did not pay for the window as this came out to about a 50/50 split on the total cost. I told them there was no guarantee on the job and from then on, I have never worked on tempered glass without informing the customer of the dangers and that I would not be held liable for anything that should happen either while doing the job or after.
[ December 30, 2009, 11:30 AM: Message edited by: David Thompson ]
-------------------- David Thompson Pro-Line Graphics Martinsville, NJ
I'm not this dumb, it's just the paint fumes talkin' Posts: 396 | From: Martinsville, NJ | Registered: Oct 2001
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