Cleaning Glassware

[jgriffin]

What do people here find the best way to clean their flasks etc after using them to make starters? I find i end up with a ring of gunk that doesn't just soak off. I've thought of using brushes, or dishwasher powder, but don't want to scratch or pit the glass at all or create anything that nasties could live in.

Are bottle brushes fine to use? Or should i stick with sodium percarbonate?

 

[Ross]

What do people here find the best way to clean their flasks etc after using them to make starters? I find i end up with a ring of gunk that doesn't just soak off. I've thought of using brushes, or dishwasher powder, but don't want to scratch or pit the glass at all or create anything that nasties could live in.

Are bottle brushes fine to use? Or should i stick with sodium percarbonate?

[post="95367"][/post]​

I'm surprised the napisan isn't lifting it - works great for me...

 

[jgriffin]

Yeah it normally works great, but these last lot don't want to budge. Even after soaking for a week, you can see a slight ring on them.

 

[NRB]

What about using some NaOH?

 

[jgriffin]

Well it's been quite a while since i did chemistry at uni, but that's sodium hydroxide isn't it? Doesn't it pit glass?

 

[Darren]

What do people here find the best way to clean their flasks etc after using them to make starters? I find i end up with a ring of gunk that doesn't just soak off. I've thought of using brushes, or dishwasher powder, but don't want to scratch or pit the glass at all or create anything that nasties could live in.

Are bottle brushes fine to use? Or should i stick with sodium percarbonate?

[post="95367"][/post]​

JG,
Dishwasher machine powder will clean your starter flasks like magic. No reason not to use it on starter bottles.
I reckon it is the only way to clean them.
cheers
darren

 

[Wortgames]

Just to split hairs, borosilicate glass (ie Pyrex etc) IS subject to attack from strong caustic solutions (dishwasher powder is caustic).

Pyrex is generally considered safe with 30% caustic solutions at ambient temperatures - with increasing heat and caustic concentration their resistance drops sharply.

More info here: http://www.pegasus-glass.com/pyrex.asp

and here: http://www.qvf.com/en/Equipment_1/Borosili...mposition.shtml

 

[NRB]

Well it's been quite a while since i did chemistry at uni, but that's sodium hydroxide isn't it? Doesn't it pit glass?

Yes and No. That's yes for question 1 and yes and no for question 2

Sodium hydroxide slowly reacts with glass to form sodium silicate, so glass joints and stopcocks exposed to NaOH have a tendency to "freeze". Flasks and glass-lined chemical reactors are damaged by long exposure to hot sodium hydroxide, and the glass becomes frosted.

I've soaked bottles in NaOH for extended periods of time to get gummy labels off without noticing any difference to the glass. I'm suggesting short term exposure and a bit of scrubbing.

Darren's also correct - dishwashers use a very caustic detergent which would affect the grime exactly the same way.

 

[sosman]

What do people here find the best way to clean their flasks etc after using them to make starters? I find i end up with a ring of gunk that doesn't just soak off. I've thought of using brushes, or dishwasher powder, but don't want to scratch or pit the glass at all or create anything that nasties could live in.

Are bottle brushes fine to use? Or should i stick with sodium percarbonate?

[post="95367"][/post]​

Sodium percarbonate works for me every time.

 

[Batz]

Bit of bleach and top up with water and let it soak for a hour of two

Batz