Australia's Science Forum

I have some stained glassware that is driving me mad. Looks clear when wet, but cloudy white stains when dry. These arent limewater stains, must be something else, and also gas jars that we used for crystal gardens. I cant find where I put the "recipe" to remove waterglass stains
Anyone help?

Hi Rainbow-sky,
I'm doing my glasswear too. I start with a good long soak in Napisan.But, like you, a few come out clear when wet, cloudy when dry. So from there, I've wiped mine over with metho on cotton wool. That worked for some. The rest, I very carefully swirled a small amount of HCl in them, just tipping the HCl from one to the other, so I didn't have to use a lot, then diluted it right down, and flushed down sink with more water. That removed everything, and I only used a very small amount of HCl. Of course, make sure you've got all your safety gear on.
Cheers,
Lisa

Try soaking them in diluted HCL. WHen the students have experiments and they use HCL, I just put it in a large 2.5 bottle, labeled unknown CONC. HCL USED FOR CLEANING. I top it up with what ever HCL is left in beakers etc. And I use this HCL on hard stains, fill the test-tube up or beaker, bottle, leave over night, and most of the stains go. I recycle HCL that way, when it no longer works, It gets neutralised with Sodium Bicarbonate, then down the sink it goes. I often can use the HCL about 4 times in all.

Hi All
Try a solution of oxalic acid.I always have a bottle made up ready. It can be used over and over again. It is great for rust or brown stains on glasswear(stains disappear right before your eyes!!) and I'm sure it will clean other things as well.
For 0.5M use 2.7g in 500mls of distilled water.Keeps for ages.
Cheers
Mother

Thanks guys.. I'm on to it