Gaggia Classic Cloudy Water

[MrJack]

It depends on how much acid is there. Adding more than you need wont be a big deal, provided you rinse it well afterwards.

[JojoS]

I'll stay out of the acid treatment subject but will add that a small amount of baking soda added to warm water will neutralise the corrosive action of malic and citric acid. I bathe boiler parts in this solution after an acid bath; then a good rinse in warm water before reinstallation.

Interesting suggestion but how small an amount? 1 tablespoon diluted to 1 liter of tepid water? If so, it will be perfect for initial rinse after descale.

[sprezzatura]

I'll stay out of the acid treatment subject but will add that a small amount of baking soda added to warm water will neutralise the corrosive action of malic and citric acid. I bathe boiler parts in this solution after an acid bath; then a good rinse in warm water before reinstallation.

[metho]

Ugly, but reminds me of older Gaggia's that I have pulled apart to fix. I not sure that is scale. I have personally assumed that it is corroded aluminium for the upper boiler. I you pull everthing apart it is easy to clean out and fix. However you will need to replace o-rings.

If you do open them force water through all the orifices to clean them quickly.

[burr]

Fair enough Mal, I don't want anyone to damage their machine, I'm just of the opinion that openly discussing ideas and sharing information can only be a good thing.

People are already abusing their gaggia boilers with citric acid, which at least outside of this forum, appears to be the standard remedy. While there might not be any immediately noticable damage it can certainly cause corrosion over the long term. Some commerical solutions aren't suitable either, nor is your standard backflush powder. My Cafetto proudly states on the back it follows "NSF protocol P152... not corrosive to the espresso machine...", well stick your aluminium shower plate holder in it and see what happens? Once I discovered this first hand I posted it up and saw other users state the same thing - I would have rather read about it first before drinking the first few layers of my backplate.

Anyway enough for now, all I'll suggest is that people only use cleaning products which specifically state they are safe for aluminium - don't assume otherwise. Regardless of what you use, make sure you flush it liberally with water after.

[Dimal]

Honestly I'm not pulling this out of my arse, I do have a PhD in chemistry

Fair enough mate, but a small amount of knowledge in the wrong hands, improperly applied, can be disastrous....

I wouldn't be encouraging anyone to experiment and try to create a home-brew descaler just because of something they've read in a forum. Much easier, safer and simpler to go with either propriety ready-made compounds from Cafetto or similar, or the weak citric acid solution that a lot of people have been using safely (although not necessarily efficaciously) on their home machines for many years.

Another common compound that we all use daily but can be very dangerous when it's individual elements are mixed in the presence of an ignition source is H₂O.... Makes about as much sense as a reference to salt...

Mal.

[GreenBeanGenii]

Honestly I'm not pulling this out of my arse, I do have a PhD in chemistry

Thing is not many users on a Coffee forum would have any inkling of the amphoteric properties of aluminium.

Abuse of aluminium could be far worse than any portafilter sneeze.

[LeroyC]

I like salt.

[burr]

I wasn't suggesting people expose their boilers to concentrated sodium hydroxide. I also wouldn't suggest they expose it to concentrated citric acid, but a correct mixture of the two would be harmless. HCl and NaOH sound nasty but 1:1 they make table salt.

Honestly I'm not pulling this out of my arse, I do have a PhD in chemistry

[Dimal]

I'll just leave it to the experts...

An industrial chemist, I am not but I do know that exposing aluminium to strong alkalis like NaOH or Ca(OH)₂ is a bad thing to do, and dangerous...

Mal.

[metho]

Most domestic products are mostly citric acid with some other acid in small quantities (Tartaric, lactic, sulphamidic acid, maleic acid). Commercial product use the big gun of phosphoric acid.

Other addatives can be:
Aluminium sulfate <1% - not sure of the purpose. It is a flocculating agent so maybe helps keeps things (floc) in suspension to remove particles.
Sodium carbonate - washing soda/water softner/ph regulator (alkaline)
Sodium percarbonate - oxidising agent
Sodium triphosphate - water softner in soaps
Polyethylene glycol - maybe used as a dispersant to prevent clumping settling of particules

I am in no way suggesting that people mix up thier own descaler with any of those additives, but it is interesting to know of some of the things put in these products.

[burr]

I've wondered that too... there's probably some base like NaOH to buffer it out? I've used products like that before which just list citric and tartaric acid, but I think the 'triple action' style cleaners also contain some detergents. Bombora's just lists "non scheduled organic acids", "other non-hazardous ingredients" and "water" in its MSDS

I bet you could read up on some patents to work it out, although I suspect the simpler descalers are just bufferd organic acid solutions. I've been meaning to figure out a citric acid + cream of tartar equivalent for people to use

[metho]

Apart from Tartaric Acid I would love to know what the other 40% is.

An example MSDS for a descaler:
Ingredients Name, CAS Proportion
*Citric acid, 77-92-0 >60%
*Tartaric acid, 87-69-4 5 -10%
Ingredients determined Not required, Balance not to be hazardous

The "Balance" would appear to be less than 30-35%.

Yes- the other components are used to break up plaques of scale that those who use it neat find fouling solenoids, gicleurs etc.

We pick up the pieces frequently and I can assure you that 40% matters.

[pcqypcqy]

Sarah

If you're feeling adventurous, are even slightly handy, and are out of warranty, have a go at pulling it apart for a deep clean. I did this on mine the other week after owning my machine for 9 years or so, with the odd service here and there. Getting some of the parts apart was.... interesting. But I managed to do it without damaging anything critical. Gave it all a good soak in descaler and manually cleaned before putting back together. Lots of videos on youtube to guide you.

That said, occasionally I get cloudy water after a back flush, but it usually runs clear pretty quickly.

David.

[JojoS]

It's just dirty. Give the shower screen and dispersion plate a good scrub.