Can I make a window from beer bottles???

[BarstowRat]

I was refered to this site by a glassblower I called and said that my questioned is more closely related to stained glass making, so here goes. My brother and I are planning on making a log cabin up in Northern CA and doing everything old fashioned (no modern tools or equipment) and thought it would look odd with modern day windows. He had what we thought to be a great idea, now we just need the technical advice to know if it's a viable idea. The plan was to recycle old glass from beer bottles, windows, etc. Make a heavy steel mold about 12"x12", pour in crushed glass and heat it so that the glass will melt and fuse into a single pane. so my questiones are:
1)is it possible to do?
2)will it be safe for a window or super fragile?
3)is there a better way?
4)anything else i need to be aware of?

[Richard Gross]

It's possible, but probably not all that practical. You'll run into a lot of problems with annealing because different glasses expand and contract at different rates, which can call tensions in the glass that will lead to breakage.

I have a friend who built a bottle wall in a cabin he made down in the Ozarks. He got the idea from Backwoods Magazine, although you can find the same idea on Wikipedia. (http://en.wikipedia.org/wiki/Bottle_wall)

[Vic Rothman]

It's possible, but probably not all that practical. You'll run into a lot of problems with annealing because different glasses expand and contract at different rates, which can call tensions in the glass that will lead to breakage.

 (http://en.wikipedia.org/wiki/Bottle_wall)

You are describing coefficient of expansion not annealing.  However, your concern is correct

[BarstowRat]

So even if all the glass came from one source, crushed and melted in a mold it would still be very problematic as far as a window is concerned?

Is there another way to make a simple, "old fashioned" type window? Our plan is to do everything like... colonial williamsburg...

By the way, I appreciate any and all your info, as glass is something I have no knowledge of.


Thanks you,
Joshua

[Richard Gross]

If the glass came from one source, you wouild reduce (but perhaps not completely eliminate) the problems from COE that Vic mentions. You would likely still have a problem with anealing. Heating the glass up and melting it is easy; you could build a furnace to do that with some fire brick, a propane tank, and about a hundred and fifty bucks worth of hardware -- a lot of it simple, off-the-shelf stuff. The annealing soak is going to be more of a problem on a do-it-yourself scale; so is cooling the glass slowly.

Now, I'm just assuming you don't have ready access to a lehr or a kiln that could hold the glass at temperature and then bring it through the annealing process properly. If you do, then a lot of your problems are eliminated and there's no reason not to give it a try. Really, there's no reason not to give it a try, anyway -- the worst that can happen is it breaks, and you're really not out all that much unless you're planning on making a large investment in equipment.

There are also souces for glass that looks like the old glass with a lot of texture. For example: http://www.agwglass.com/. It would look good, and you wouldn't have any expense for equipment or any trial-and-error process to make what this fellow makes commercially. I understand that on a project like you're describing, the do-it-yourself aspect can be really a lot of the point, but buying the glass is an option.

[Vic Rothman]

"doing everything old fashioned (no modern tools or equipment"

How old do you want it to look?
Window glass was spun into large disks and then cut into window lites, this was done till the mid-1800's. After that window glass was blown into cylinders that were cut open and flattened, this continued to around 1900. Then glass was mechanically "blown" into very large cylinders , flattened and cut up. In 1955 the "modern" method of making window glass was invented.

There are NO guarantees when melting found glass. Even bottles from the same drink company may be made at different glass factories and may not be compatible (COE)

[BarstowRat]

Well thank you all again for all the information, it really does help and I appreciate it all. From what all of you are saying, (in my mind) glass seems to have alot of the same properties of metal (I know about metal).... "uncontrolled" heating and cooling removes the tempering process making it brittle, right? So (assuming) like metal, tempering is "controlled" heating and cooling i.e. temp. vs. time. Alot of tempering is done by quenching or burying in a pit of sand to either rapid cool or slow cool. I know metal can take abit more abuse then glass, and I guess the long question short is, how much more delicate would it be for glass to temper?


As far as how old of a look, well I enjoy making things myself, so that to me is the basis of the whole project. I really don't want to buy alot of stuff and I just think that crystal clear, modern wondows would look out of place on a rustic cabin. That and I can't take any pride in saying "Hey, I bought that!" lol  However, my wife has ever-so-lovingly been encouraging me to salvage some windows from an old house. That or making... not sure how you guys call it, stained glass but with clear glass...

Thanks again,
Joshua

[Vic Rothman]

Well thank you all again for all the information, it really does help and I appreciate it all. From what all of you are saying, (in my mind) glass seems to have alot of the same properties of metal (I know about metal).... "uncontrolled" heating and cooling removes the tempering process making it brittle, right? So (assuming) like metal, tempering is "controlled" heating and cooling i.e. temp. vs. time. Alot of tempering is done by quenching or burying in a pit of sand to either rapid cool or slow cool. I know metal can take abit more abuse then glass, and I guess the long question short is, how much more delicate would it be for glass to temper?


As far as how old of a look, well I enjoy making things myself, so that to me is the basis of the whole project. I really don't want to buy alot of stuff and I just think that crystal clear, modern wondows would look out of place on a rustic cabin. That and I can't take any pride in saying "Hey, I bought that!" lol  However, my wife has ever-so-lovingly been encouraging me to salvage some windows from an old house. That or making... not sure how you guys call it, stained glass but with clear glass...

Thanks again,
Joshua

Without getting overly technical. There are 3 very different issues being discussed here. 1-COE/coefficient of expansion. Glass moves with temperature changes. Different glass moves at different rates. If you melt these different glass together they will break.
2- annealing. This is the slow cooling of glass to remove internal stress. This does NOT affect the COE problems.
3 Tempering. This is the deliberate introduction of stress to glass to give it strength. This is done with specialized equipment. Again this does not effect the COE. Also you cannot cut tempered glass

[Richard Gross]

Joshua, it's not a perfect analogy to compare metal to glass, but it's not really all that bad, either. In metal, you temper to balance hardness, brittleness, flexibility and such so that you end up with a usable tool. If you're making a knife, you want the back to be softer so the blade doesn't break and the cutting edge to be harder so that it holds a good edge, but not too hard because then it become brittle and breaks under normal usage. Of course, you can make a perfectly good knife blade by heating it up to a working temperature in your forge, working it for shape and reheating it as it cools, then when you're satisfied tossing it into a metal box full of wood ash to cool down to room temperature so you can do clean up work, fit your guards and bolsers, and so on. Then you heat to a tempering point (much cooler than the forge temperature) and oil quench (or whatever is appropriate for that particular steel) it so its usable, make and fit your handle, polish and sharpen, and you're done. And obviously I'm taking about how they might be made by the craftsman working on a small scale; there would be some differences if you walked into a facility where they make a hundred-thousand of them in a year.

Now, what you're describing in your post for tempering is, in glass terms, actually annealing. Also, this COE you keep hearing about is coefficient of (thermal) expansion. Vic's description is a good one for that; glasses that are different chemically will expand and contract at different rates and if they aren't compatible, they will break because of the stress they put on each other as they expand when heated and contract again when cooled -- maybe not immediately, depending on how close they are -- or likely in the annealing stage.


If I was going to do what you're talking about doing it and under the conditions your talking about, here's how I'd go about it:

First, I'd select my glass. If I wanted to be really picky, I'd get a glass for fusing (say System 96) and eliminate the COE issue. More likely, though, I'd pick out a glass I thought was going to be compatible and use that. I probably wouldn't pick bottles, because even though they might look the same they might not be where it counts. I'd probably pick window glass that you get from the hardware store and give that a shot, first.

Next, I'd make that small frame you were talking about and set up a ground furnace to work with. I'm guessing from the questions you're asking you know how to do this, but briefly: dig out a pit to size and run and bury the line for the blower. Then place your fire bricks, pack the sides around the bricks with earth or an earth/wood ask mixture. Run your fire line and nozzle, put your frame and glass in, put a fire brick roof on the thing and light it up.

Get it cooking really good and wait for the glass to glow a nice, bright orange, then give it a little longer just to be sure. Cut your blower; count ten; cut your propane. Cover any open holes in your furnace to keep any contamination out of the inside, and then pack the whole thing in dirt and let it cool off as slowly as it will.

Of course, you're going to want to keep children and pets away, a fire extinguisher handy, make sure nothing combustible is nearby, don't burn off your eyebrows and keep your arms and hands inside the ride at all times.

Do I think it will work? No, I really don't. Would I try it myself? Oh, heck yeah.

What you'll probably end up with is glass that will break easily. But with a project like you're describing, it doesn't sound like you'd really be out anything if it does. And if it does work, well, you're going to have bragging rights over the windows in just about any self-built cabin I've ever seen. Which, by the way, is well more than one.

Oh -- and make sure your jet isn't pointed straight at the glass. Above is fine.

[Richard Gross]

One other important thing -- you're going to need a kiln wash or a  shelf paper to separate the glass from the fire brick and the frame. Just google "kiln wash" or "kiln shelf paper" and you'll find it. Otherwise, the glass will stick to the fire brick and frame and it will all be ruined.

[Vic Rothman]

casting glass WILL leave a texture on the glass. The only way to get it optically clear will be to polish the glass.

[BarstowRat]

Thank you all for your vast wealth of knowledge. I do believe that I have come to the conclusion that this will be a fruitless endeavor to try and "make" a window with my average-Joe knowledge. It would be real crumby to have a window break in the dead of winter. All that said, I will certainly give it a shot. Heck, with no expectations I certainly won't be disappointed when it breaks lol. This won't be for awhile thought, but when I do I will certainly keep you posted with my experiements and give you some pictures to laugh at.


Thank you all so much for everything,
Joshua

[Richard Gross]

Please do, Joshua -- I would love to see how it works out!

[Enrique Laks]

Of course it can be done but I would not recommend it. There is a small catholic chapel near our home and studio with several windows made with bottles. Those bottles were set laying down one next to the other and one on top of the other: most of them are already broken, with air going through them. It might perhaps work if arranged in a different way but the windows do not look nice at all, the whole job does not seem to be very convenient. I would not waste any time or money in such a project.
Enrique

[Javahut]

Just some random comments and information:
the coefficient of the glass you are melting can become homogenous if you melt all the glass to 2300 deg F and hold it there for an hour, then all the glass in the pot will have mixed and become the same COE.  Want to take a wild guess about the crucible cost and melt cost, need to go up slow so you don't thermal shock the crucible remember, may take 2 days to get it up to temp, with only a small amount of glass in it, when it is at temp you can add the rest of the glass to make one sheet, or more, figure 1.3 lbs per sq ft.  a 40 lb capacity crucible I recently sold is $155 to replace.
an inexpensive annealing oven can be built with kiln brick and metal grate (expaneded metal, with the holes) and as tall as you want.  reasonablely,  saw one in a glass blowers workshop that was about size of a small furnace, and heated with a weed burner running off a large propane tank. opening in the bottom for the burner to stick in and an adjustable vent at the top.  Put the burner in, turn it on and adjust it so when you open the side door and put a pieve of wadded newspaper on the shelf, close the door count to 3 by one thousand one, one thousand 2 and open on 34 and it should burst into flames!, then the temp is correct for annealing, leand it adjusted for that temp, inside dimensions, 2 x 2 ft,,,5 ft tall.  Crude buy efficient, he used that to anneal 3 inch dia  paperweights for 30 years.


When your glass is hot enough, ladle it out onto a steel marver and rool it with a large diameter pipe, good gloves, scoop it with a thin piece of plywood with 1 x2 handles and slide it onto the shelf in the annealer.  windowglass is there the next day.  all crude equipment, and your cost will go down with the number of sheets produced.