Authoritative Answers, Fun, & Aloha -- no cost, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Home /
Site 🔍
pub     mobile?
Metal finishing Q&As since 1989


Sodium metasilicate - is it a cleaning agent?

[editor appended this entry to this thread which already addresses it in lieu of spawning a duplicative thread]
Q. Good day

Normally the anodic cleaner before my alkaline zinc plating tank contained only a sodium hydroxide solution. As such no contaminant issues with drag-in (or very little) are created in ways of parts coming out after anodic cleaning and being put into the alkaline zinc bath which itself contains sodium hydroxide.

Some cleaner solutions contain sodium metasilicate. I am wondering what is the common way to rinse this thoroughly from parts or neutralize before going into the Alkaline zinc bath, as not to drag in anything that can negatively affect the plating process.

Currently I'm not aware of what effects sodium metasilicate has if dragged into an Alkaline Zinc plating bath, and to what degree.

I am thinking a rinse tank with a small percentage of a certain acid, but which?


Boris Siljanoski
- Perth, Western Australia
June 22, 2022

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,

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

⇩ Related postings, oldest first ⇩

Q. What is best for cleaning, if not sodium metasilicate [on Amazon (adv.)] ? Is sodium metasilicate a biodegradable substance?

- KL Malaysia

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

or eBay or


(affil links)

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.

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Multiple threads merged: please forgive chronology errors :-)

Q. Would sodium metasilicate [on Amazon (adv.)] be a recommended product as a cleaning agent for PVC (as an vinyl awning cleaner)?

Pat Braithwaite
- Langley, B.C., Canada

"Advanced Cleaning Product Formulations"
by Ernest W. Flick

on AbeBooks

or eBay or


(affil links)

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.

Robert Zonis
- Havre de Grace, Maryland

A. In my experience, sodium metasilicate [on Amazon (adv.)] 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 Szabo
- Jacksonville Florida
December 4, 2009

? It seemed that there may be some concern about using sodium silicate as a cleaner in your response to another question; what is the concern, its abrasive properties or what?

Thanks, Larry

Lawrence Scrima
- Aurora, Colorado

Ed. note: Sorry, Lawrence, there are thousands of responders here and tens of thousands of threads; it's unlikely that your inquiry will draw a response. Probably better to put it directly on that "response to another question" thread.

Q. Where can I buy 'water glass' [on eBay or Amazon (adv.)] ?

Ariel Alepuz
- Miami, Florida

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.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Multiple threads merged: please forgive chronology errors :-)

Purpose of sodium metasilicate in Degreaser?

Q. What is the function of Sodium metasilicate in the degreaser solution during degreasing action. Is it used only to make the solution alkaline or it has more function during the coarse of action.

Arasu Krishnasamy
engineers - Singapore
September 11, 2008

A. Very often sodium metasilicate [on Amazon (adv.)] 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!

Martin Michel
- Bielefeld, NRW, 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.

- Warsaw, Poland
October 5, 2008

Q. Dear all,

I am trying to formulate a high foaming alkaline cleaner, degreaser and brightener for aluminum and copper. With the little information I have got, I am planning to make a composition of sodium hydroxide, sodium metasilicate and some non-ionic surfactant. Please advise what more can be added to the formulation for getting better results.

Thanks and regards,

Alcott Fox
formulator - London, UK
April 25, 2009

Q. OK, I can clean iron with Sodium Meta Silicate in my emulsifier solution but it rusts within hours. Tried a phosphate with no joy? Any ideas which is the best to use?

Zak Johnston
cleaners and adhesives - Birmingham, West Midlands, UK
July 19, 2011

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.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. I bought a trisodium phosphate [on eBay or Amazon (adv.)] 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.

Charlie Davis
- Tampa, Florida
July 24, 2011

A. To Charlie Davis comment:
Based on an experience with a customer complaint about municipal water, make sure that what you are trying to remove is a film of residue and not etched glass. Some combinations of dishwashers and detergents permanently etch glassware and changing cleaners won't help.

Frank Skee
- High Point North Carolina US
July 28, 2011

Q. I have used a sodium metasilicate [on Amazon (adv.)] based cleaner for 7 years. My container is nearly empty. It has worked effectively on ceramic tile, cement-based tiles, vinyl and aluminum siding and removes stains from carpet textiles, including nylon, polyester and acrylic, quite thoroughly. I first used it to remove salt and road dirt from my car's floor mats. I recommend it as a safe and effective home cleaner.

Follow the directions exactly on the package to make it mild, medium or heavy-duty strength, mixed with a specified amount of water. Use it outdoors or in a well-ventilated area (turn on some electric fans and open the doors / windows if using indoors).

I always wear rubber gloves [on eBay or Amazon (adv.)] when mixing and applying it mixed with the appropriate amount of hot water, according to the package directions. I use a wide-head bristle brush with a short handle to apply it to carpet fibers, tile and siding. Scrub till a slight foam appears, rinse with clear water and allow to dry. When cleaning carpet fibers, vacuum up the water with a shop vac or blot up well with old towels.

In the many years I have used this sodium metasilicate [on Amazon (adv.)] cleaner, I have never had any problem from fumes from the product, or with damage to any material or textile I used it on as a cleaner. However, that brand is no longer produced or available for sale in North America, so I am looking for an equally safe and manageable substitute.

Carol Shetler
- Oshawa, Ontario, CANADA
March 14, 2012

Powdered Brewery Washes
on eBay or


(affil links)

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.

Ben Hocking
- Walton, Kentucky

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 :-(

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Q. Hi I was looking up sodium metasilicate regards to cleaning Macrocarpa timber boards or Cedar weather boards. Any info will be appreciated. --Chris

Chris Boyes
- Wellington New Zealand
September 19, 2012

Q. What other chemical can I use with sodium metasilicate when manufacturing engine degreaser and what ratio?

Bright Chinhema
supplier of chemicals - Harare, Zimbabwe
June 12, 2013

thumbs up sign The powdered TSP substitute cleaners [on eBay or Amazon (adv.)] 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.

Bill Wilson
- Longview, Texas USA
October 26, 2015

Q. Is sodium silicate biodegradable? I guess it is not ... then what is the replacement for it in detergent having same working as it has?

Shoukat Muneer
- Lahore, Pakistan
February 15, 2016

Air Filter
Cleaner Spray

on eBay or


(affil links)

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.

June 17, 2016

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.

dave wichern
Dave Wichern
Consultant - The Bronx, New York
June 23, 2016

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 [on eBay or Amazon (adv.)] about 12 inches away to dry the surface of the oil and canvas quickly.

Steve Clark
- Vancouver, BC, Canada
January 31, 2017

Q. Used dishwashing liquid with sodium Meta-Silicate and sodium hydroxide with surfactant in large amount water. Some spray got on glass and paint of car. Seems like hard water stains. How can I remove from both surfaces?

Sam hoffman
- Watsonville, California, usa
April 25, 2020

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
& Software

About/Contact  -  Privacy Policy  -  ©1995-2024, Pine Beach, New Jersey, USA  -  about "affil links"