Acid-based hard water removers- long term glass damage?

bumblebee · January 27, 2012, 12:01pm

What is “hard water?” Before you can clean or restore a surface, you first have to understand what issues you have and how to deal with those issues. I hope I am putting the chemistry involved into plain language.

Hard water is caused by dissolved minerals, usually in the form of carbonates (calcium carbonate, magnesium carbonate and so on). The carbonates precipitate out of the water and leave the white “scale” behind on the glass. Using an acid dissolves the carbonates back into solution so they can be removed.

The resin in your DI tank works much in the same way. Hard water can be softened (have its minerals removed) by treating it with lime (like most local city water systems treat drinking water) or by passing it over an [U]ion exchange resin[/U] (inside your tank) . The ion exchange resins are complex sodium salts. Water flows over the resin surface, dissolving the sodium. The calcium, magnesium, and other cations precipitate onto the resin surface. Sodium goes into the water, but the other cations stay with the resin.

Back to the acid washers, besides removing the carbonates, the acids also remove silica and other minerals that were used to produce the glass. Think of it as using microscopic sandpaper on the glass. It removes microscopic glass pieces like a surgeon cleans a wound by debridement.

Over a period of time, it will damage glass. Also, when you “grind” glass to restore it, you open up “fresh layers” of glass that other oxides can cling to. This causes the minerals to attach more readily so in a way, restoring glass and leaving it unsealed can cause the stains to appear to come back quicker.

Think about when you grind on steel, the clean steel is bright and shiney, but the fresh exposed steel will attract oxides and form rust.

I believe many chemical product manufacturers actually do a dis-service to window cleaners because they don’t educate the end users (the guy with the scrubbie in their hands) properly in how to use their products.

Crystal Clear is a great product for certain situations. It should [U]not[/U] be the first product pulled from the tool box to remove water stains on glass. It contains HydroFluoric acid, which is extremely dangerous if not handled properly. Question, would you use a 12 ga. to kill a fly? CC is that shotgun.

Each window and stain issue needs to be evaluated as an individual incident. Using a 1 product fits all mind set is not only un-wise, it can be hazardous to your health.

mistersqueegee · January 27, 2012, 12:09pm

Good points Bee. Since we have the Glass Renu system I don’t have to use the shotgun (CC) I can use the laser scalpel (GR).

michaelmole · January 27, 2012, 1:58pm

“Laser scalpel” sounds a bit much for killing one little fly…

mistersqueegee · January 27, 2012, 4:06pm

Yeah but if it had cancer on one of it’s wings I’m set.

Run · January 27, 2012, 10:05pm

Bee:

Thanks for the breakdown!

Questions:

So if acid does damage glass over time, what does the damage look like?
Can grinded glass be sealed?
What are your go-to’s for mineral deposit removal?
Oh and what type of acid use frequency can damage glass? Say I use it quarterly on the same piece of glass.

mistersqueegee · January 27, 2012, 10:13pm

1 - damage can be varied from etching to staining
2 - Yes. Glass is always porous and grinding just removes a thin layer revealing normal glass underneath that is still porous.
3 - Slayer powder, Bio Clean, OneRestore, and Glass Renu
4 - some have reported staining issues w/ OneRestore and CC550 will etch the tin side of glass.

JBeauty · January 27, 2012, 11:35pm

If it isn’t a mild acid and you leave it on in the Sun it can and most likely will ruin the glass if your slow or sloppy. So I never leave acid on a piece of glass longer than it takes to clean it; I would try to avoid doing it in direct sunlight, some acids will ruin glass if you put it on that way. I have to agree with -optimummaintenance-'s comment that he is just trying to separate himself by saying what he either believes to be true because he sucks, or because he is lying to get more business. Either way its because of idiots saying that stuff like that can interfere an entire region of a market if not the whole market. When people read that a majority of window cleaners are rip offs and want to purposely ruin your glass it makes us all look bad and incompetent even if its not true. It would be like a bum of a cop coming out and saying “all cops are pervs and want to pull over women to flirt” or that “they all steal drugs from criminals”, the public would be like “oh if its coming from one of them it must be true” and all cops would be hated (example).

Run · January 28, 2012, 7:17am

JA:

Yeah, I hear ya. Look up this http://windowcleaner.com/vBulletin/showthread.php?t=12282

That was an experience I had a year ago. Learned my lesson.

I actually apply acid to glass and keep it on there and wet for 15 minutes. You won’t see results with a one minute set. But like you said, it must stay wet the entire time.

On another occasion I saw a rainbow-like shiny area on a window after I used acid for hard water removal. I don’t know what it was. Maybe tin side etching. Maybe what bumble bee said. I’ve been using the same acid for six years, never had that happen before or again.

Tony:

Thanks for all the info. Why do you use powder? What is the benefit? Also, can you show a pic of etched glass?

HE_MAN · January 28, 2012, 1:51pm

Most of this makes sense when doing single panes of glass.
So what would you do when it comes to cut ups that have water stains on them?
What would be the best and quickest way to do the job?

mistersqueegee · January 28, 2012, 2:40pm

Run - I use a powder because I can carry it in my pouch for those minor hard water issues. I can add a little to my strip washer or bronze wool for a quick touch up.
I don’t have a pic in my computer of tin etch haze. I’m sure there are some on this forum. TEH has a similar appearance to oil on water (weird rainbow looking swirls). And if it’s a more severe etching like acid tag graffiti it will be rough to the touch. Sorry I couldn’t be more help.

Run · January 30, 2012, 11:20am

Thanks! Severe etching must be scary.

Ryan · February 1, 2012, 2:38am

I just ordered CC 550. After reading many posts, I have decided it was a bad idea. I saw a couple of videos and read a couple of reviews and was convinced that it was a great product, but had to be handled with deep care. So what should I use to restore glass as a newcomer in this business? I have seen other videos of Cerium Oxide and that seems to work as well. What exactly is the process of glass restoration? And, how does one tell if the tin side is on the outside or inside of the glass? I have so much to learn it hurts.

mistersqueegee · February 1, 2012, 8:08am

We use have a Glass Renu system and a few other stain removers. With the Glass Renu system we can handle anything.

hunterst · February 1, 2012, 9:49am

Keep the Cc550 on hand and use it on windows with screen burn. That is where it works great. Always use gloves, you really don’t need to put alot on to whatever you use to apply it. I prefer a 6inch scrubber, wet the scrubber with your window solution or just plain water. We use a well labeled squirt top bottle, pour the cc550 on the scrubber, you don’t need a lot. Test in a corner for tin etch haze, if it is the tin side it will turn a hazy whitish, bluish color almost instantly.

Sent from my iPhone using Tapatalk

Ryan · February 1, 2012, 12:10pm

Thank you for your quick replies. It is nice to see others in the world who are willing to donate some time to help out beginners like myself. I don’t have the money right now for a Glass Renu system, although I am hoping to invest in something like that next year. What should I do for windows that haven’t experienced screen burn? Would a Cerium Oxide be alright? Should I buy that with a drill so I can apply it faster, or does it not really matter? Anyway, thank you for your support. I am looking to join this WCR site as a member once I get the funds in later months.

Also, when you bid a job, do you charge more for the restore applications? For instance, when I enter a customer’s home, should I sell them on JUST cleaning the windows and then if it needs the restore solution, walk them through and tell them that it is extra to get those extra stains off? Do your businesses have a lot of “just cleaning” jobs, where your employee just has to clean and squeegee the windows and be done? Anyway, thank you again.

Ryan.

ABM_Window_Cleaning · February 1, 2012, 12:30pm

Run:

I read recently on a window washer’s website that acid free removal of hard water is the best way to get the minerals off of glass because acid will have long term affects to the glass. This is his selling point. He says that most window washers use an acid-based hard water spot remover that damages glass, but is very quick. They thus choose speed over value.

Is there any good basis for this claim.

He says that half the pros out there do it intentionally, while the other half is ignorant. I’m sure he didn’t take a poll…

As someone who has done acid-based hard water spot removal for years and has seen nothing but great affects on glass, I see this as an untruth. Perhaps he has been misinformed. Chemical manufacturers would not be allowed to brand and sell their products like they do if their product damages glass with proper use, glass being the surface it is intended for. At the very least, their product would be called out by many users, lawsuits would occur, and products would be taken off shelves or reformulated.

Of course, these statements of his aren’t necessarily malicious. It is likely just ignorance that has allowed it.

Perhaps he had a bad experience in which he misused a product. Perhaps there is a bad product out there that I haven’t used. Of course, making a sweeping generalization based on one product, or worse, based on the misuse of a product is like saying that a baseball bat can’t hit a thrown baseball effectively after the bat was pushed like a pool stick toward the ball.

Note that he didn’t expound upon what the damaging affects were or how he received his information.

His stated method of choice involves spraying pure water on the window, then buffing a rubbing compound. He say’s it takes up to ten times as long to do than the acid way, but because he keeps the “interest of the customers” first, he is willing to do this. He also states that his method helps prevent future hard water spotting.

I am not necessarily against other methods, and I know other wc guys buff our spots. I just wanna get some feedback on this guy’s claims.

I know exactly who your talking about Aron haha ok so let me give you the run down. He actually USED to use acid on windows, only problem is the acid he used wasn’t made for windows, it was made for the underside of boats. He got the idea from an auto detailer (who I know also), turns out he used it on a couple of his clients windows and damaged them. So ever since then he’s never used acid.

Crazy huh?..

Run · February 1, 2012, 5:09pm

Wow. Thanks for the inside track!

ABM_Window_Cleaning · February 1, 2012, 6:14pm

Yeah not very smart, or professional.

thorSG1 · February 1, 2012, 8:16pm

sell it to me, i’ll buy it

HE_MAN · February 1, 2012, 8:56pm

Is there a reason you wet your scrubber first?
Wouldn’t dilute the CC550?
Believe it should used at full strength.