| Search our quarter-million Q&As |
Home of the finishing HOTLINE since 1989
-----How to remove silica scale from faucets, etc.
Q. I am looking for a non-abrasive method to remove silica build up on faucets, shower heads, etc.?
The white buildup I am talking about is on the plastic shower nozzle and the interior glass surfaces of the shower stall. Our water analysis shows high concentrations of silica. Is there a chemical approach to remove this type of scale?
- Los Alamos, New Mexico, USA
2007
A. Just because the water has a high silica content, does that necessarily mean the deposits are silica? Maybe it's just soap scum that will come off with an alkaline cleaner?

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2007
A. You might try cleaning it with a solution of 2-4 tablespoons of bicarb of soda in hot water, followed by a rinse followed by straight white vinegar
⇦ in bulk on
eBay
or
Amazon [affil link] (acetic acid
⇦ on
eBay
or
Amazon [affil link] 5%) works on carbonate scale but NOT on silicate; full stop, end of story.
Mild solutions containing hydrofluoric acid (HF) are the only solution to silicates scale. WHY? Because it's the same acid that's used to etch glass (Silica). Agree with previous comments; please be exceedingly careful with any solution that contains HF. I would advise:
1. Please read up as much as you can prior to use.
2. Don't get it on glass; it will etch the glass very quickly and permanently.
3. Only use where you can control the run off drips & splashes 100.00% to ensure that the acid is completely washed away at the end of the treatment.
4. Calcium Gluconate gel is the antidote for skin contact after immediate washing with water.
5. Serious contact WILL REQUIRE hospital treatment.
Now if you still want to do this you can find many HF containing cleaning solutions in aluminium mag wheel cleaners as manufacturers use sulfurIC ACID mixed with SODIUM HEXAFLUORIDE to make HF in the mixture but don't have to declare it on the label as they never added it into the product.
OK, last bit of advice : consider very carefully the potential of this to go wrong and the cost of a new shower head.
Regards,
Integrated Hygiene Management - Lawson Blue Mountains Australia
A. It is looking like Australia is way ahead of good old USA.
Forget the C-L-R, the bicarb and lemon juice and contact Gell Enterprises Inc., Fresno California. They sell, AMAZ, a product that will solve your hard lime scale problems. I have been using this professionally for several years now.
AMAZ is produced in the USA so you should not have a problem in locating.
Alpine Carpet & Tile Cleaning - Banksia Grove Perth, Western Australia
June 29, 2017
Ed. note: We discourage commercial testimonials for a lot of reasons ( huh? why?)Even still, we never hear from company lawyers when their product is praised, but do hear from them quite when their product is dissed, it should be recognized that reviews you read tend to be unrealistically favorable rather than balanced :-)
Removing lime scale from plugged nozzles
Q. My client uses hard water in the 7-stage washer for cleaning 2-piece tin-plate steel
food cans. Stages 1 and 2 run at temperatures at 130 - 150 °F. They get lime scale buildup on the nozzles and in the risers. Any suggestions to easily remove the scale from the steel nozzles and steel risers in the washers?
scientist - Collegeville, Pennsylvania
November 10, 2017
A. Hi Frank. Commercial products like CLR and Lime-Away are basically for this purpose; I don't think we'll come up with a home-brew which is better. But if the problem is too severe to deal with, it may be necessary to start with softened or DI water and/or to make up the cleaning solutions from potassium-based chemicals or at least sodium-based and avoid calcium. Good luck.
Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
November 2017
Q. A mild hydrofluoric acid solution has been mentioned for removal of silica deposits on ceramic/porcelain toilets and sinks. Is it safe for use on:
1) chrome fixtures
2) satin nickel fixtures
3) stainless steel kitchen sinks
4) fiberglass tubs and showers?
- Underwood, Washington, USA
August 21, 2019
A. Hi Shirley. It's not safe for people, that's for sure.
It's not safe on 1) or 2).
It's not 'good' for 3) but may not harm it if rinsed well.
HF eats glass, so it's not quite 'safe' on fiberglass. But as long as it's not old and wicking, or has a gel coat on it, it's probably okay.
Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
August 2019
Thank you for responding to my questions. That was very helpful.
- Underwood, Washington, USA
August 24, 2019
Q. Hello.
I would like to know if the electronic descalers on the market (like ScaleBlaster, Eddy, etc.) work on silica.
A product called ScalePro says that their descaler does work on silica.
Thanks!
- Richmond, Virginia USA
November 13, 2019
A. Hi John. Sorry, although we can certainly print general responses about electronic descalers, like whether people consider them workable science or snake oil, we can't print support or refutation of claims about individual proprietary items like ScalePro & Eddy ( huh? why?). This is a "no-registration required" website where we have no proof that anyone is who they claim they are and that they are without without vested interests. We've had several suppliers pose as 'satisfied customers' in this forum (we knew because the poster's IP address was the same as the vendor's website). Similarly claims that one particular brand doesn't doesn't work could be brand assassination by a competitor :-)
It's best to use this site for technical issues rather than testimonials; we'll leave reviews to "registration required" sites like Amazon.
Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Sorry! Finishing.com is temporarily Read-Only.
Ted Mooney is retiring but I have several offers to take it over.
We're working hard to make sure we find it the best new home.


