Introduction: Make Your Own Safety Glass and Other SHENANIGANS
You know how car windows don't shatter like normal glass windows? When they get smashed, they sag like fabric. What kind of sorcery is this? It's safety glass, and it's AWESOME!
Safety glass is made by laminating two pieces of glass together with a sheet of plastic in the middle. You heat up this little sandwich and press everything together, and the plastic melts and sticks to the glass. Once everything cools down, it looks just like a normal piece of glass, but if you smash it, the plastic holds everything together. The glass is now a composite, and it's notably stiffer than a single sheet.
As it turns out, it's really easy to make this yourself using just a bit of plastic, binder clips and a toaster oven. And once you can laminate glass, life just gets better and better.
Ready? Go!
Step 1: What You Need
I'm just experimenting with this stuff, so I'm using itty bitty pieces of material. The same process works for larger pieces of glass, though.
I used:
glass microscope slides -- $.05 each from your local science depot. Tonight, I learned that, in Manila, you can buy microscope slides at the drug store. Isn't that awesome?
EVA film -- This is a thermoplastic film that will hold your glass together. You can get it pretty cheap on ebay. Get yourself a nice bialy roll of the stuff, because you're gonna want to play with this a lot.
Binder clips -- available wherever paper is looseleaf
A cheapo toaster. When playing with chemicals, I like to use dedicated equipment so I don't accidentally eat my experiments. Heated plastics play with our bodies in all kinds of ways that we don't understand. For $10, I can get an extra toaster and avoid being an inadvertent guinea pig. Plus--science toaster!
Step 2: What You're Going to Do
Here's a sped-up video showing the process. It really just takes a minute to make a piece of safety glass.
The music from this video is by the band Beirut. Beirut made this great full-length film of themselves playing their music, called Cheap Magic Inside. Did you know that? Every time I see them singing Nantes in that staircase in brooklyn, I tear up. You should totally watch it!
Well, ready to make some glass? Spin up a Beirut album and let's go!
Step 3: Sudo Make Me a Sandwich
Well, make your sandwich and clip it up. Not much to show here--just cut out a piece of EVA and slip that between the buns. Clip it together like crazy with binder clips--pressure makes the difference between a beautiful piece of safety glass and a beautiful piece of ugly poop.
Step 4: Old Gold: It's Toasted
Now throw that sucker in the oven. EVA melts at 80 degrees C, and your oven will get a lot hotter than that. You can tell when it melts, because it turns perfectly transparent. EVA is index-matched to glass, which means that when the plastic is pushed right up against the glass, light will pass through both of them as if they were one material. As soon as the EVA turns transparent, turn off the toaster and carefully pull out your sandwich. Let it cool down, and then pop the clips off.
This photo is from an early experiment and I don't have binder clips on my sandwich. You should--everything, binder clips and all, goes into the toaster.
Step 5: Give 'er a Whack
Well, you're done. I know--super easy, right? If everything went right, your glass should be crystal clear. Give it a whack with a hammer and be astounded that it doesn't shatter like normal glass. Now go hug a sad banker.
Step 6: An Exercise for the Reader
I started playing around with glass lamination because it's the method people use to make solar panels that last twenty-five years outdoors, and my friend Shawn and I are on a mission to make the best small-scale solar panels the world has ever seen. If you make your own solar panels from scratch (here are somelovelyinstructables we wrote to show you how to do that), you can encapsulate your panels in glass and EVA to make waterproof, long-lived panels. Here's an image of the first test panel I made using this method.
You can also put other stuff into the glass. I played around with laminated leaves and flowers from my garden in between a couple pieces of EVA inside the glass. I'm particularly pleased with how my canteloupe flower turned out. Wouldn't it be cool if your car windshield had flowers built into it? Play around with it! Shove all kinds of stuff into the glass. Adhere glass and EVA to the front of a surface-mount circuit board to make lovely, glass-fronted PCBs that everyone will love. Stick glass slides to your walls. Stack two glass panes and some spacers together to make your own double-glazed windows. Go nuts!
Well, that's what I've got for now. Go forth and DO stuff!
19 Comments
8 years ago on Step 3
This is a brilliant project. thanks for the post. Will this work with large pieces..ie window glass.. I mean is the plastic you use here the same for larger projects that are required to meet code? If so I am gonna go and laminate all my downstairs house window panes
8 years ago on Step 6
did the flowers work the same way
11 years ago on Introduction
In Australia, "safety glass" means the stuff that shatters into thousands of little bits, so that there are no large shards that could penetrate the body.
Your example is called "laminated" and is usually only available for windshields. When my car's back window shattered, I made sure the replacement had tint film right to the edges before being fitted back into the rubber seal. If it shatters again, it will be held in place by the tint film.
Ironwolfcanada mentions that "safety glasses" are not made from glass. They are usually made from polycarbonate, which means they don't like exposure to oils.
Have you experimented with various colors introduced into the plastic layer?
Reply 9 years ago
Mate I make safety glass for a living in Australia and the majority of safety glass in windows is laminated with pvb not just car wind shields. The glass that shatters into tiny pieces is furnaced glass aka toughened. We laminate that too. There is regulations on what type of glass that is glazed into building. High rise buildings should be 13.52mm laminated toughened. Normal houses regulate that windows have to be 4 mm float and thicker.
Reply 11 years ago on Introduction
Safety glass is made for glass. The plastic that sandwiched in between the two planes of glass is polycarbonate plastic.
Reply 11 years ago on Introduction
From my wikipedia search, both of the types of glass you mention are solutions to the same problem of keeping glass from becoming millions of tiny knives when it breaks. The glass that shatters into thousands of tiny bits is tempered glass, and it's the strongest glass available (according to wikipedia).
The laminated stuff I make in this instructable is actually pretty common in architecture. If you run your finger along the edges of cheap, fancy glass walls, you'll feel something rubbery -- that's the edge of the EVA or TVB film in between two laminated pieces of glass.
I saw somewhere that you can also laminate polycarb to glass, which sounds pretty frickin cool. I really like the idea of laminating multiple colors together--I'll have to go dig up some polycarb and give it a try
Reply 11 years ago on Introduction
I think the stuff that shatters into little bits is tempered. I think that kind is best for cars, because once broken, it has no leverage to slice someone open. The laminated stuff seems like a good option for tall buildings so people can't fall out of a broken window.
Prank, have you experimented with multiple layers of glass to stop projectiles?
11 years ago on Introduction
I like this idea very much, but when I searched eBay, I couldn't find the thermal plastic product under the name you supplied. Can you give more information please?
Reply 11 years ago on Introduction
Many thanks for that Prank, the concept and discriptions you have given can help anyone who wants to do this project for making their own laminate.
Noel
Reply 11 years ago on Introduction
Hmmm. Did you check the link from the materials page? It goes to an ebay vendor that's selling EVA film, and this ebay search for EVA film turned up a bunch of results--http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=EVA+film&_sacat=0
Reply 11 years ago on Introduction
Here is a link to EVA Plastic Films
http://www.blueridgefilms.com/eva_film.html
And here is another link to all kinds of links to Eva films
http://isearch.avg.com/search?cid={3F5688F2-A5DC-4CFB-8282-3678D765DDA5}&mid=6826f94916fccf73643815153ead7b87-9557abddcd2a82ce3aec9d57c4d569e029d61ac8&ds=AVG&lang=en&v=11.1.0.12&pr=pr&d=2012-03-29%2016:55:24&sap=dsp&q=eva+film+properties
Hope this will end the controversy here.;>}}
11 years ago on Introduction
This would be great for picture frames!
Reply 11 years ago on Introduction
also have you noticed how well insolated the car is with windows all over it? i think larger glass panes might be a cheap alternitive to the sweet double pane windows. plus when i toss a bat through them again it wont make such a mess.
yes when i was in high school i accidently threw a bat through my grandmothers back window. double pane and 9 billion shards of glass later the bill was close to 600 bucks. and that was in the 90s.
Reply 11 years ago on Introduction
Not sure where you live but respectfully you seem to never spent much time in a car or in a home with single pane glazing in cold weather. Glass is great conductor of heat, not an insulator.
11 years ago on Introduction
I have worked with laminated glass, can size cut and finish it.
This is a great kids science experiment. Interesting, but not suitable for real glazing.
Anyone wanting "laminated glass" cannot go wrong just going to a glazier. It is relatively cheap to have glass cut to size, choosing strength and thickness of quality laminated glass, for automotive use or domestic.
The glass 'experiment' is most definitely not 'safety glass' as that is toughened glass. Toughened glass is either heat strengthened or fully tempered glass.
http://www.youtube.com/watch?v=uA7RTxX2KL0
Laminated manufacturing of glass is done with annealed glass.
http://youtu.be/VTKLjtcbnn4
For some laminated windscreens fitted in certain European model vehicles glass is heat strengthened and zone toughened laminated glass. Both glass processes used for occupant safety.
11 years ago on Introduction
Interesting idea - thank you.
The EVA film is expensive! I wonder if you could use 'low E' film instead.
11 years ago on Introduction
Neat idea, and has numerous applications,
BUT, not for "safety glasses"!!!
When safety glass breaks, tiny shards of glass DO separate from the plastic
core, and if you were wearing "safety glasses" made with glass,
it's highly probable that these shards of glass would get in your eyes.
This is why 'safety glasses' are NOT made from glass!
Keep up the neat ideas!
11 years ago on Introduction
excellent instructable......
11 years ago on Introduction
Very good idea!
I like the "captions" on the video, because I can read English but I don't understand it when spoken. Thanks for that.