Pyro - 30-4-2012 at 16:54
today my father asked me to clean 4 350$ crystal decanters because they were completely white inside, so i suggested H2SO4, and he thought it was a
great idea, so here goes:
#1: I mix sulfuric acid and water to dilute it a bit, and i waited for it to cool down, and poured it in... crack, broke into many pieces
#2: same thing
#3: it got nice and clean and i washed it all out and it went into the dishwasher
#4:it broke as well
so i collected all the shards and was wondering if i should give them to a glassblower to make a condenser? because it seems a pity to throw all this
expensive glass away.
bbartlog - 30-4-2012 at 18:12
Hm... at such a price I daresay i would have changed cleaning methods after the first one broke.
And if it won't withstand dilute sulfuric acid I don't think you can use it for lab glass.
Pyro - 30-4-2012 at 18:19
well, we guessed that that was the only way, because we tried stones, lead shot, decalc, ball bearings,... and none worked. i think they cracked
because of the heat, because i don't think that H2SO4 will cause any glass to break, no?
[Edited on 1-5-2012 by Pyro]
Migratory - 30-4-2012 at 18:23
Just how hot did it get?
Pyro - 30-4-2012 at 18:37
hot to the touch, it hurt to hold it for more than 5 seconds, id guess about 70 degrees.
it could be that they got non-visible cracks in them when they were jammed in a box, and they do go through a lot of shaking because of the engine.
but is crystal any good to get a condenser made?
[Edited on 1-5-2012 by Pyro]
Migratory - 30-4-2012 at 18:41
Yeah, sounds like they were damaged. All my crystal can survive boiling water. Anyway, it might be less expensive to buy the glassware than it is to
have it custom blown. It depends on your glassblower's rates.
Pyro - 30-4-2012 at 18:46
i know about the resistance to heat of crystal, almost all our glasses are made of crystal.
ill check out the rates, i know a glassblower is handy for custom equipment.
it seems a pity to throw all that extremely expensive glass away...
Endimion17 - 1-5-2012 at 06:04
The "white stuff" is calcium carbonate. Why on earth would you want to clean that with sulphuric acid, if the reaction gives insoluble calcium
sulphate?
Not only it's fairly easier and less expensive to obtain hydrochloric acid, but the product is pure solution of calcium and chloride ions that can be
rinsed away. How were you supposed to rinse away something that's essentially gypsum?
I think the glassware broke because of the formed precipitate in the scratches and pores.
Sulphuric acid is never used for cleaning limescale because it just makes the problem worse. HCl is for limescale, NaOH/detergent is for grease.
Neil - 1-5-2012 at 06:26
"Crystal ware" = by deffinition leaded glass.
Usless for anything other then cutting into pretty shapes that go tinnnnnnnnnnnnnnnnnnnng when you flick them.
If it is just Crystal then it could be leaded or unleaded but is likely a high K glass mixture. Not much use for it...
Pyro - 1-5-2012 at 09:39
well it seemed to have an effect on the one that didnt break, it was completely white, now its clear.
it must have caused it to lift off the surface?
ok, ill throw it out.
thanks for the help