We have a bunch of simple pint glasses and smaller juice glasses that have developed a hazy bluish/white surface after years of use, so I thought before replacing them, I'd see if I could clean them up a bit. Some of the damage was done shortly after we put in a water softener years ago and didn't reduce our detergent enough, but they've gotten progressively worse over the years.
I remember in school, chemists always had base baths with potassium hydroxide that did a good job of cleaning up glassware if it was allowed to soak for an extended period of time, so I figured I'd give it a shot. As I recall, it slowly etches the glass surface. I poured a few gallons of water into a large rubbermaid container and added a load of cool wood ashes from the stove, and then dropped three glasses into the mixture.
After a couple of days, I didn't see any real improvement, but after a couple of weeks, they look great! It doesn't take out scratches, but the glass is crystal clear as good as it was when new. The water has a very slippery feel to it so it's obviously got a pretty high concentration of base in it - rinsed immediately after pulling the glass out.
I'll probably run all this through a homemade straw/cloth filter to separate the ash particles and then continue on with more batches of glassware. I've read that some people would use such solutions to eventually make soap - when I'm done, I might try concentrating it outside in the sun to see how much KOH I can recover. Anyone know just how much can be recovered per pound of ash? I'm sure we have a true laboratory chemist on here somewhere...
-Colin
I remember in school, chemists always had base baths with potassium hydroxide that did a good job of cleaning up glassware if it was allowed to soak for an extended period of time, so I figured I'd give it a shot. As I recall, it slowly etches the glass surface. I poured a few gallons of water into a large rubbermaid container and added a load of cool wood ashes from the stove, and then dropped three glasses into the mixture.
After a couple of days, I didn't see any real improvement, but after a couple of weeks, they look great! It doesn't take out scratches, but the glass is crystal clear as good as it was when new. The water has a very slippery feel to it so it's obviously got a pretty high concentration of base in it - rinsed immediately after pulling the glass out.
I'll probably run all this through a homemade straw/cloth filter to separate the ash particles and then continue on with more batches of glassware. I've read that some people would use such solutions to eventually make soap - when I'm done, I might try concentrating it outside in the sun to see how much KOH I can recover. Anyone know just how much can be recovered per pound of ash? I'm sure we have a true laboratory chemist on here somewhere...
-Colin
