Sciencemadness Discussion Board

Serious descaling

jgourlay - 8-1-2014 at 04:43

Gents, there is a wonderful invention called the 'zojirushi'. It sits quietly next to the coffee pot, keeping water hot for whenever I need it. It's a wonderful, wonderful thing.

But, it's got a serious scale problem. Scale sticks like a barnacle to the side until it breaks off in huge chunks that floats around. It gets nasty.

My normal solution to this would be vinegar, and attack with a rough ss scouring pad. But, this particular model has a polymer (teflon??) lining, and I don't want to scratch that up. It's too soft even for scotchbrite.

I need a chemical solution, one that is unlikely to fubar the pump seals, that can be reliably flushed from the system so I don't poisen us, and that will work. My first instinct was dump a shot glass of concentrated H2SO4 or HCL in there.

But I thought I'd ask here, first.

ScienceSquirrel - 8-1-2014 at 05:09

Most commercial descalers use citric acid.
Lactic, sulphamic and formic acids are also used.

Zojirushi have a product that is based on citric acid and the machine has a nifty cleaning cycle as well so put your sulphuric acid away!

http://www.zojirushi.com/products/cdk

plante1999 - 8-1-2014 at 05:10

I think there is a product in north america called CLR that supposedly works.

Pyro - 8-1-2014 at 05:10

don't use H2SO4, that makes CaSO4, plaster of Paris. use HCl, but diluted.

the wisest course of action however, is to buy a descaling kit. that way there is no risk of damaging your thing.

Nickdul - 8-1-2014 at 05:32

A product I use commonly has these listed on the MSDS:
Citric Acid: <60%
Tartaric Acid <35%
EDTA <5%
The packaging is 250g and is supposed to be diluted with 750 to 1000ml with water. You can make out the percentages and try it.

jgourlay - 8-1-2014 at 11:57

Quote: Originally posted by ScienceSquirrel  
Most commercial descalers use citric acid.
Lactic, sulphamic and formic acids are also used.

Zojirushi have a product that is based on citric acid and the machine has a nifty cleaning cycle as well so put your sulphuric acid away!

http://www.zojirushi.com/products/cdk


SWEET!!! Thanks for that!