In the 1950's and '60's weather barometer animal figurines were popular. They usually changed color when the weather was going to change from sunshine to rain or snow. After a period of time they stop working (changing color). I am curious as to what chemicals they were coated/painted with that made them work and if it would be possible to recoat one and have it work again.

tickle

They were coated with mercury based paint which is outlawed now, so I dont think it is likely you will get any to recoat.

mjacobs

Thank you for the quick reply. I did not think it was a paint at all. I really thought it was some kind of chemical mix that had been applied to the figurines. It did not feel or look like paint. They even had some spots where the "color" crystallized. When they aged they stopped working and turned a golden brown color and washing them literally washed the substance off leaving you with a white figurine.

tickle

whatever it was, it was mercury based.

Capuchin

Tickle, I'm not so convinced. A search doesn't bring up much, but if it was detecting the humidity levels then it was probably some kind of saturation indicator.

Do you remeber the colors it went mjacobs?

The information I can find suggests that one of the best chemicals for the job would be Cobalt (II) Chloride.

This turns from blue (CoCl2), to purple when it absorbes 2 water molecules (CoCl2.2H2O) to pink when it has absorbed 6 water molecules (CoCl2.6H2O).
This reaction is reversible. So it will turn back to CoCl2 when the water is driven off by dry weather.

Does this tie in with how you remember it changing color? I have to admit i'm too young to have seen these devices.

Further reading: Cobalt Chloride Paper. This is used as an indicator for water.

Please keep in mind that if this sounds like the stuff then it is now labelled as Toxic, Harmful to the environment and "Probably carcinogenic". Back in the 50's it was probably enough to label it as "WARNING - TOXIC" but nowadays it's a little more compicated. This is not stuff you want to let kids near, or to play about with if you're not sure of what you're doing.

It'll probably cost a bit to dispose of correctly too.

mjacobs

Yes that does sound much like it! My Grandmother always had a "weather poodle". It would be blue, turn pink when it was going to rain, grey when it was going to snow, and violet meant a weather change was coming. There was never a warning label on them! The closest thing I could find after looking up storm glass was a sealed version that was made up from camphor, ammonia, alcohol, potassium nitrate, and water. That made crystals appear in the water when the weather was changing. Since the poodles had spots that crystallized I assumed it was some kind of chemical and not paint. The Cobalt (II) Chloride explains all but the turning grey. I take it restoring one of these to working condition is pretty much a no-go then. Sad because for me they hold wonderful memories of Grandma's house. I do appreciate all the help and interest I have received. Thank you.

tickle

Please view this website:

Antiques, Art, and Auctions: Maine Antique Digest Magazine

If I am wrong about the mercury, but dont think I am, then no one, absolutely can use it, and if they have it must take to a government outlet for disposal.

mjacobs

After reading on that site I am ready to dispose of every mercury thermometer in my house (if I can figure out which ones do for a fact have mercury in them). I contacted an antique dealer who said the figurines he remembered were coated with a Cobalt solution and then a binder. Mercury or Cobalt (II) Chloride - either one, from what you and Capuchin have told me are both dangerous so the poodle figurines that I have (which over the years by several owners have been washed until they are solid white with no trace of "color" left) will be left alone in their present state and kept stored in a glass cabinet where no one will handle them - just in case. Originally I thought it would be nice to re-coat one and have it work like in the good old days but sometimes the good old days were not so good huh. Thank you so much for all the time and research you have put into this.

mjacobs

Just a point of interest -
On this site they mention pictures or figures being coated with Cobalt Chloride: AMS Glossary

Although the poodles were sold as animal barometers seems they were really a chemical hygrometer.
I have also found that the solution can be made from Cobalt Chloride, salt, Calcium Chloride and water.
I have learned SO much today.

mjacobs

Sorry that link did not take for some reason.
AMS Glossary
then I put chemical hygrometer in the search box