Descaling Water Still using Citric Acid

Discussion in 'Supporting Chemistry' started by JHRoss, Aug 14, 2019.

  1. Hello all,

    I would like to know which would be the ideal concentration of citric acid solution to use for descaling the boiler of the lab's Water Still

    Hint: In the Water Still's Manual says:

    "Into the open funnel of the constant level control carefully add

    about 1 litre of 10% formic acid solution or kettle descaler."

    Furthermore I would like to know how long should I keep the citric acid solution in the boiler for better results without ruining it.

    Last edited: Aug 14, 2019
  2. Not sure that citric acid would shift it. You could use kettle descaler if you haven't any formic acid, although you might want to read though your manual first, I've never tried it.
  3. Well it is not very active, but I gave it only one hour in the boiler. The manual of the Water Still suggests kettle descaler as well
  4. Why, it's just citric acid


    Attached Files:

  5. greenfingers

    greenfingers Sarah G

    my new still has 100ml conc HCL in 100ml water leave for 2 hours drain and flush through a couple of times.
  6. I use HCL too - you can see the scale 'melting' away
    Darius likes this.
  7. I took mine down on Wednesday, I think i may need to drill it out, there is about 1cm solid limescale on the bottom which the acid is not shifting.
  8. used a hammer and chisel in the end, then gave it a final go with citric acid. and it came up sparkling clean.

    Thankfully it is a stainless steel boiler.

  9. Well the thing is that big pieces of scale keep existing inside the boiler. In a ideal scenario the scale should be totally extinguished, shouldn't it?
  10. greenfingers

    greenfingers Sarah G

    After only using my new still for a week i've noticed the glassware becoming cloudy,have asked for a water softener to be added to the inlet pipe
  11. it's surface area is low so it will take time to react, it's quicker to physically remove it if you can.