Chelators/sequesters?

[Kev888]

For some time now I've been using my own cleaning mix of 2x Sodium Percarbonate to 1x Sodium Metasilicate. It works very well for removing heavy/dried deposits through soaking, but I can't leave for too long or I get white deposits forming on whatever is being soaked. I could be wrong but I believe these are some of the salts precipitating out of my solution (though possibly some limescale from the water).

Chemistry is not exactly a strength of mine; I believe what I need are chelators or sequestering agents but then I run out of understanding. Can anyone tell me if there is a simple way to get and add such things? Or in fact if I'm barking up the wrong tree.

Thanks,
Kev

[RajBoab]

Don't know much about the chemistry myself but I've used plain soda crystals or a mix of soda crystals/sodium percarbonate in the past. I've often added a tiny drop of unscented washing up liquid hoping it would provide some wetting agents/something to improve the cleaning properties.

Would love to someone in the know to suggest something powdered we could add to a metasilicate/percarbonate mix to make it even better!

Stuart

[Kev888]

Yeah, a powdered one would be really great, but I'd be willing to add to the mixed solution if not.

I was listening to the chap from five star chemicals saying that PBW can be used weaker and longer than the recomended dose, and sometimes I just want to soak for longer with heavier soiling, so getting my home made mix to soak without deposits sounds useful.

Cheers
kev

[Graham]

Something like Calgon powder should do the job.

Trisodium hexametaphosphate was used in many cleaner formulations as a calcium sequester and the original Calgon was simply that chemical. These days Calgon is some other chemical due to concern about phosphates getting into water courses and the like, but it should still do the same job.

Alternatively a spray with a vinegar solution and then a rinse should remove the deposits once formed.

[Kev888]

Many thanks indeed Graham, thats exactly what I was hoping for; excellent stuff!

Cheers,
Kev

[jmc]

Something like Calgon powder should do the job.

Trisodium hexametaphosphate was used in many cleaner formulations as a calcium sequester and the original Calgon was simply that chemical. These days Calgon is some other chemical due to concern about phosphates getting into water courses and the like, but it should still do the same job.

Alternatively a spray with a vinegar solution and then a rinse should remove the deposits once formed.

That sounds really interesting.

Maybe Calgon (or SHMP) could help clean up any residue after soaking too long with Oxy and also for cleaning boilers.

http://en.wikipedia.org/wiki/Sodium_hexametaphosphate
http://www.sciencelab.com/msds.php?msdsId=9924995

Looks like its use in loads of processed foods.
Extract from http://www.hplus.co.uk/img/Fine-Sodium- ... e-Spec.pdf

Sodium hexametaphosphate acts as an excellent sequestrant, curing agent, emulsifier, firming
agent, flavor enhancer, flavoring agent, humectant, nutrient supplement, processing aid,
stabilizer and thickener, surface-active agent, synergist, texturizer and buffering agent: Cheese,
Cured Meats, Desserts, Dips, Eggs, Fillings, Fruits, Gelatin, Ice Cream, Imitation Cheese, Meat,
Milk Based Beverages, Pet Food, Polymers, Poultry, Processed Cheese, Processed Meat,
Seafood, Sour Cream, Starch, Syrups, Toppings, Vegetable Protein, Vegetables, Whey,
Whipped Toppings, Yogurt .

[Kev888]

Something like Calgon powder should do the job.

Trisodium hexametaphosphate was used in many cleaner formulations as a calcium sequester and the original Calgon was simply that chemical. These days Calgon is some other chemical due to concern about phosphates getting into water courses and the like, but it should still do the same job.

I got a pack of calgon powder last night, so thanks for the info Graham, the description on the pack looks to be ideal. If its of any interest, the current pack says >30% Zeolite and <5% polycarboxylates.

I also noticed that it was next to a Sainsbury's own-brand water softener, which was about half the price for nearly twice as much. However aside from containing sodium sequicarbonate this gave no quantities or other ingredients, so (even if I understood the relative chemistry) it would be hard to compare what you get for your money - on this occasion i went for the calgon instead.

Cheers
Kev

[Graham]

Strangely, Calgon has completely different formulations for different products; powder, tablets, liquid, express ball etc.

Here is a series of articles on how Calgon works:
http://www.chemistryinyourcupboard.org/calgon/10
It should open on the page that gives the ingredients for the dual action tablets. The neutralisation sections in the side-menu explain what the individual chemicals do. Notice that sodium citrate is the major ingredient.

Compare it to the powder here:
http://www.rbeuroinfo.com/index.php?SKU ... ANGUAGE=EN
Quite different.

It seems possible that you might have got away with simply adding a bit of citric acid to your mixture.
http://en.wikipedia.org/wiki/Monosodium_citrate

[Kev888]

Most interesting - thanks once again, Graham. I'd not even considered calgon formulations would differ much between the packaged types.

The citric acid is a good thought too - I've used it to remove the deposits, but not as a preventative. Its probably more convenient for me to get hold of calgon in practice, but if the prices are much better it'll be worth a try.

Thanks
Kev

[Martin G]

Just read the bottle of Bar Keepers Friend in my cupboard;

Citric Acid Monohydrate
Sodium Carbonate
Oxalic Acid

No indication of quantities, but thought I would mention as it adds further support to the suggestion to add some citric acid to the mix. Citric acid seems a sensible choice since it is used to passify steel. The mix in Bar Keepers Friend is awsome at cleaning steel, it cleaned some stains from the gas burner on my steel within seconds. Had not thought to use it routinely, probable due to the £3/200g a bottle cost. Not really sure where oxalic acid fits in really, know it is used as a rust remover and bleaching agent.

Sodium Carbonate can be got for £1/kg
Citric Acid £6/kg

What concentration would you aim for?

[jmc]

Just read the bottle of Bar Keepers Friend in my cupboard;

Citric Acid Monohydrate
Sodium Carbonate
Oxalic Acid

No indication of quantities, but thought I would mention as it adds further support to the suggestion to add some citric acid to the mix. Citric acid seems a sensible choice since it is used to passify steel. The mix in Bar Keepers Friend is awsome at cleaning steel, it cleaned some stains from the gas burner on my steel within seconds. Had not thought to use it routinely, probable due to the £3/200g a bottle cost. Not really sure where oxalic acid fits in really, know it is used as a rust remover and bleaching agent.

Sodium Carbonate can be got for £1/kg
Citric Acid £6/kg

What concentration would you aim for?

Oxalic acid may be included to remove any rust

see here

Its found naturally in rhubarb too!

[orlando]

Anyone considered cleaning the gear straight after using it I always do