Suggestions for cBleach residue cleaning?

Is anyone experiencing a similar situation that an impenetrable gunk collects at the bottom of a distillation flask after short pathing and nothing seems to clean it?

We have tried everyting…

  • Acetone
  • Heptane
  • Denatured Alcohol
  • Easy Off Oven Cleaner
  • Dawn dishwashing fluid
  • We haven’t tried an ultrasonic cleaner yet but are considering it.


I dump it hot into a bucket of cold water to dispose of. Then soak flask in alcohol, then ultrasonic with alkali cleaner.

Works like a charm


Thanks for the feedback. I just need an ultrasonic cleaner big enough for my 6L flask.

pirana solution if u cool with that sorta thing

What is pirana solution?

Just Wikied it. Ugh

Get some alconox, make a hot solution, and soak. I’ve had it remove screenprinting from glassware too, powerful stuff.I usually rinse all glass with solvent, then place into a hot bath overnight. Scrub it with a bottle brush in the morning, any residue should come off fairly easly. Also works good for an ultrasonic cleaning solution.

Oxyclean & warm water followed by acetone - has always worked for me. This is of course for WF still bodies and WF components - and not SPD kits. Most WF have a Clean-In-Place.

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A link to the info i used when I started using carbon in the flask


I’ve often wondered if activated charcol under the heat and vaccum of a distalation actually keeps the absorbed components. Lately I have filtering it out prior. I started finding a trend on my data logger, distalations with the carbon generated slightly more vapor pressure. Just out of curiosity have you seen this too?

Anecdotally, you can add molecular sieve beads to the boiling flask and the beads will keep the clay from sticking to the flask until it cools down completely.


we just ran into this problem… our stir bar was completely stuck in the sludge/crust at bottom of boiling flask. hot ethanol and a two day soak cleaned the top half of flask, but didnt do anything for the sludge. warm acetone and a two day soak worked very well! stir bar is unstuck, and after a quick ethanol cleaning, we are back in business.

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Ethyl Acetate and it’s gone

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Is nobody removing or filtering out the cbleach prior to loading the boiling flask?

I am.

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