Help me get my anachronistic snake oil business off the ground

February 20, 2011 10:01 AM

How can I make new glass look like old, buried glass?

How can I make new bottles look like those bottles that you dig up that are etched and opalescent with age?

posted by small_ruminant to grab bag (15 answers total)

Do you really mean opalescent, or just wobbly and uneven? Either way, I don't think the effect you're looking for is caused by age.
posted by jon1270 at 10:13 AM on February 20, 2011

Here's an Evil Mad Scientist Labs piece on faking beach glass. It probably wouldn't work with whole bottles, though.
posted by phunniemee at 10:20 AM on February 20, 2011

My first thought is to rig up something that pours or shoots sandy water at the bottle as you slowly spin it to keep the aging effect evenly distributed.
posted by scalefree at 10:31 AM on February 20, 2011

You can do it with a tumbler. A tumbler is a cylinder filled with coarse sand and water, which is rotated for (typically) several days. You'd need to find (or make) a big enough tumbler (I'd guess bucket-sized). Making them isn't terribly difficult if you can find the right motor and gear it so that it turns at a fairly low rpm (say 5-10).
posted by le morte de bea arthur at 10:45 AM on February 20, 2011 [1 favorite]

You can buy glass etchant at a craft store.
posted by theora55 at 10:53 AM on February 20, 2011

Etching cream.
posted by glibhamdreck at 10:55 AM on February 20, 2011

It's not exactly etching- when you unearth them around here (Bay Area) they really have an iridescence that's really neat, and not even, so I don't think the bottles were manufactured that way.

Here's one, courtesy of google.

And here's another.

Someday I will learn how to do that tinyurl thing that I've seen other people do.
posted by small_ruminant at 11:11 AM on February 20, 2011

Getting the scratched and pitted surface is easy - see above. What's hard is getting the iridescent layer that forms during years underground, like you see on Roman glass. Here's a method involving some fairly nasty chemicals and a kiln. Proceed at your own risk. (I have no experience with this method, I just Googled it up using "iridescent glass how to make".)
posted by Quietgal at 11:15 AM on February 20, 2011

Thanks, Quietgal. That's probably the way to go, only with a very dilute solution. It looks like that makes that super rainbow iridescence and we're looking for subtle.

I am still hoping someone will come up with a solution that involves something passive- like burying it in a box full of X solution and dirt or something.
posted by small_ruminant at 11:22 AM on February 20, 2011

The term you're looking for is "glass patina". Google reveals
posted by bubukaba at 3:10 PM on February 20, 2011

...a number of how-tos! (oops!)
posted by bubukaba at 3:30 PM on February 20, 2011

(More background information, with some tantalizing hints about the chemistry behind the process in nature here. Seems as if the chemical composition of the glass is just as important as the composition of whatever you immerse it in).
posted by bubukaba at 4:10 PM on February 20, 2011

I have some 'art jars' that were faux-aged to look like they'd been in the water/on the beach, and it looks like they liberally applied etching cream, if you're interested in examples: here and here, full set here. It looks aged, if not in the exact way in the photos you linked.
posted by lhall at 8:35 PM on February 20, 2011

I am not a chemist, but I do know a few. Glass corrosion is a common problem in the solar business. It's caused by water leaching sodium ions out of the glass. This forms sodium hydroxide (NaOH) at the surface of the glass. If the NaOH is not removed (by running water for example), then the pH will increase (NaOH is a strong base). Eventually the pH is high enough to attack the glass. Typical glass corrosion makes the glass opaque with a white powdery or greasy texture. I suspect that the cyclic nature of annual weather will gradually build very thin semitransparent layers that cause the iridescent patina you're looking for.
posted by Long Way To Go at 8:36 PM on February 20, 2011

Tumbling is going to create a fairly uniform effect. You might be able to mitigate that by covering only parts of the bottle with something that the sand has to wear through before it starts wearing on the glass. Maybe unevenly applied paint, dollar store epoxy, shellac or even masking tape ripped to get rough edges.

small_ruminant writes "Someday I will learn how to do that tinyurl thing that I've seen other people do."

One doesn't need to tinyURL on Metafilter. In fact it's use is discouraged. The links you created are just fine.
posted by Mitheral at 1:46 AM on February 21, 2011