Sodium metasilicate - is it a cleaning agent?

A. Hi Boris.
I have personally never heard of anyone adding anything to the rinse to deal with the metasilicate so I suspect that nobody does and that it's not actually a problem.
Luck & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 6, 2024

"Practical Guide to Industrial Metal Cleaning"
by David S. Peterson

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A. Hi, Wilson.

"Cleaning" is a complex physical reaction that involves sequestration, detergency, saponification (reaction of alkali with fats to forms soaps), inhibition, and other facets. So there is not one single chemical which is the "best" cleaner. Rather, commercial cleaners are usually made from alkali, detergent, builders, and other ingredients. But, yes, sodium metasilicate is an important part of many alkaline cleaners.

Sodium metasilicate (SiO3Na2.5H2O) is an inorganic compound rather than an organic one, so I'm not sure that the term "biodegradable" precisely applies, but I believe it breaks down further rather than persisting in the environment. Good luck.

A. Sodium metasilicate is not a cleaning agent by itself. It is a VERY strong base. The pH of a 1% aqueous solution is about 13. In moist air it is corrosive to metals like zinc, aluminium, tin and lead, forming hydrogen gas. As a strong base, it reacts violently with acids. A major use is as a builder (a material that enhances or maintains the cleaning efficiency of a surfactant, principally by inactivating water hardness) in soaps and detergents.

It may be used as part of a component in a chemical degreaser, where it would react with fatty acids(animal grease) to form a soap, which is then rinsed away.

Not something I would recommend for household use.

Sodium silicate, on the other hand, is an abrasive white powder frequently used in things like toothpaste. It doesn't clean by itself either.

A. In my experience, sodium metasilicate ⇦ this on eBay or Amazon [affil links] is [truly] an excellent cleaning agent. I cannot state with certainty if it will clean PVC [proviso] "without damage to its applied surfaces". I would not hesitate in testing though to satisfy my curiosity or need. It would seem to me that simple laundry detergent or that of an equal grade would be sufficient for the application originally queried (awning exterior).

You see, PVC or ABS plastics have a propensity to deteriorate under the sun's UV rays. In my applications, it is used as part of a process to vitally and thoroughly clean ferrous metal, typically after sand-blasting, finish removal, or acid pickling etc.

The manner in which I use it, the water is heated to and stabilized at a temperature of 180 °F then mixed at a ratio of 4-5 oz's per gallon of water. (by the way, I use a filtration system which removes sediment, minerals, bacteria and finally deionizes the water).

This agent may be acquired as a liquid or powder. I prefer the powder (white crystal-like in composition).

As with all specialized cleaning operations, SAFETY is key! Adapt or elect a safety protocol before using this agent as this solution is a VERY STRONG alkaline! You may elect to follow safety protocols outlined in documentation such as OSHA guidelines (i.e., safety procedures for the handling of this powder, liquid or solution; exposure(s), first aid, etc.) Protect yourself and those around you. Alkaline burns are dangerous as well as very injurious.

Best regards,
Alex

A. Hi Ariel.

We appended an advertising link giving you some mail-order sources, and telling you what sodium silicate is and its uses.

You can google for many other sources. If you are interested in reviews, most such products on Amazon have user reviews attached.

Regards,

A. Very often sodium metasilicate ⇦ this on eBay or Amazon [affil links] plays a role in increasing the electroconductivity and saponification of the degreaser.

It inhibits the redeposition of contaminants on the workpiece, saponifies acidic substances and thereby promotes the solubility of oil components, and the like.

Best regards from Germany!

A. In my opinion the main purpose of use of metasilicates in degreasing is to replace phosphates. Martin's reply is true, but the purposes he pointed out are characteristics of metasilicates rather not purposes.
Regards,

A. Hi Zak.

Good alkaline cleaners for iron and steel saponify, wet & emulsify, deflocculate, chelate & sequester, buffer, and inhibit. You can certainly formulate your own if you wish, but proven mixtures are commercially available from metal finishing process distributors.

Yes, raw iron and steel will rust in hours -- sometimes they'll flash rust in minutes -- but cleaning solutions which leave the metal with an alkaline disposition can deter it for a while. Sometimes merely dipping the parts back in the cleaner and letting it dry on the metal can provide a temporary rust-proofing. A better approach when applicable is to immediately move on to the next step of waxing, oiling, black oxiding, phosphating, or plating.

Regards,

A. I bought a trisodium phosphate ⇦ this on eBay or Amazon [affil links] hard surface cleaner.

It contains Sodium Meta-Silicate and Phosphate. I am going to add it to my dishwasher because my glasses have a cloudy like stain. Most Dishwashing products had to remove Phosphate per State law I think 36 states banned its use.

Powdered Brewery Washes

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A. I use a cleaner called PBW, or Powered Brewery Wash ⇨
It is mostly Sodium Metasilicate originally designed for Coors Brewing Co. It is excellent at removing any sort of protein based scum. It can be purchased at a home brewer's shop in sizes from 1 to 8 pound tubes and online from 1 pound to 50 pound drums. My experience it works great but not to be used on Aluminium.

A. Look for another brand with as close to matching ingredients as you can find, Carol. The SDS (safety data sheet) for most products is on line so you can see the basic ingredients. Just google "SDS (brand name)". Or you can look to Amazon for product reviews :-(

The powdered TSP substitute cleaners ⇦ this on eBay or Amazon [affil links] are mostly sodium metasilicate. I mix some of that with liquid laundry detergent to spray on customers' driveways which have the black crud growing on them. I don't rinse it off either. It kills the crud and over time it decomposes into dust which can be swept off with a broom or water hose. Sodium metasilicate is widely used to prevent fungal growth on picked melons and other produce.

A. FYI, sodium metasilicate pentahydrate is the single chemical in K&N [brand] "Air Filter Cleaner" [UPC: 0 24844 00030 9] ⇨
for their line of semi-permanent auto engine air filters. It's available at virtually any California auto parts store, so presumably in all other states also.

The K&N product number is 99-0606, also in a kit 99-5000.
There is no indication of what the strength/dilution is, but it doesn't damage the air filter fibers or rubber filter frame.

I have no affiliation with this manufacturer.

A. I'd imagine it's fully biodegradable. When it is mixed with other wastes and the pH comes down, it should hydrolyze into colloidal silica, which there's already plenty of in most receiving waters.

A. First off Sodium Meta-silicate is biodegradable. For those looking for a general purpose cleaner that is available everywhere ... Spray Nine. I've used this stuff for all my cleaning needs and it has worked very well for all applications. My latest application is cleaning nicotine and tar off old oil paintings. If you are going to try that, do a test spot first but really I haven't found it to be an issue with oil paintings. Spray it all over the painting and watch the brown crap stream off ... I quickly rinse off the painting and use a blow dryer ⇦ this on eBay or Amazon [affil links] about 12 inches away to dry the surface of the oil and canvas quickly.