Crystal Clear leaving a "shimmering" to the glass

Hi Guys! I’ve been doing residential for 13yrs and to remove screen burn wore out my arms/hands with 0000 wool till I finally settled on crystal clear. I’ve only had one time when it caused the glass to totally cloud up and luckily had a paste recommended to clear the glass and put it on my drill buffer and it worked and became clear again.
The problem I have always had is that after using the crystal clear correctly it always left a “wavy, shimmering” to the glass particularly when the sun was on it. Contacting Winsol about this they knew nothing. My thought is that the screen burn is removed but the glass is slightly distorted by the acid causing this “shimmering” effect.

Your thoughts??

(I have tried One Restore but the strong odor caused some dizziness and I didn’t like breathing it. Yet it didn’t seem to leave that shimmering as I recall, but my total recall on that is somewhat dubious, LOL!!)


I’m Alan Lott, We Do Windows, Richmond,VA

Glad to have you here with us :). I guess my reply was a little cryptic. I was using a mention tag to summon our resident chemistry expert, Henry Grover. He’ll probably be able to give a full explanation of what’s going on with the CC-550.

Excellent!! I usually figure that out but my early morning 2 cups didn’t quite do it!!LOL!!:cool:

Alex you are very kind. Truth is I am just a crazy old tinkerer that likes to play with chemicals.

And Alan, I will give you a general run down of my experience. Hope it helps.

Hydrofluoric acid otherwise known as HF, can cause a second stage dynamic etch. It can totally break down all the elements of a glass surface and rinse them away. Another term used for this effect is total dissolution.

I remember a call I got about 20 years ago from a man talking about banding and orange peal. The building had spots and silane rundown. A solution/product based on HF was used to remove the hard water spots and silane drips/rundown. Which left a clear banding effect where the long drips of silane were. Also a clear orange peal where the hard water spots were. The glass was tinted dark. The case was quite complicated and interesting. I can tell you other stories. And have described a couple of tests using HF and other etchants on my blog. They demonstrate the different types of etch that can be created on glass. It can happen in thirty seconds.

We have some leaders in the field of glass restoration. They all use grinding and polishing techniques. And never suggest using acids that etch glass. I will be the first to state that these people are well in advance of me in the development and use of this technology. Despite this I am quite sure that there will always be people that use HF and other destructive acids on window glass. However these days I am much more focused on more safe answers.

Alan, you appear to be an intelligent man. I wish you the very best in your business. And want to say welcome to this forum! If you want to talk about certain details regarding specific products just send me an email.


Thanks for the response Henry. In my experience, the hydrofluoric acid in crystal clear always causes a second stage dynamic etching which appears to the eye as a shimmering distortion. It saddens me to tell the customer that what I use is suggested to remove screenburn but the etching is a byproduct of the removal, that the glass is slightly burned by the acid which causes that shimmering distortion. Yet I tell the customer that the cloudy haze that the screenburn caused is now gone and they agree and are very happy about that, and so far after 10 yrs of using crystal clear no customers have complained after the fact. So I have mixed emotions about using Crystal Clear which was suggested to me years ago by JRacenstein staff who I hold in high esteem.

So my question to the other members who deal with screenburn is: Have or do you use Crystal Clear and if so did you see that burned distortion effect??? And if so, do you still use the chemical for screenburn and what do you tell the customer about it?? I always tell them to remove there metal screens after removing the screenburn. But removing the screens makes that shimmering effect more apparent, again, no complaints after the job. If you don’t use crystal clear what do you use and does it remove the sb or leave any residual effects to the clarity of the glass???


I agree with your first statement about HF always reacting with the glass. I think if more building owners actually knew what was going on there would be more lawsuits. I have been called in as an independent consultant over some very famous buildings over the last 25 years. There is way more ignorance over this matter outside of our industry than inside.

Silicate deposits (hard water spots) require a grinding and polishing technique. Screen burn however is a different chemistry. So chemicals like the alkalies sodium hydroxide, and sodium metasilicate will remove it without doing the kind of damage that HF will. Still I prefer pure optical silica powder, cerium oxide, or 0000 steel wool to remove it. Different combinations of these along with an alkali will also work. Usually I start with my SKRUB product or the powder it is based on in water. If that doesn’t work I might add a few crystals of sodium hydroxide. Or mix a mild solution of sodium metasilicate (water glass) along with the silica powder. Water glass is another alkali. To give the silica/alkali solution more kick I might rub this with a piece of 0000 steel wool. The glass comes out beautifully clean. No acids. I prefer no alkalies. And will always go for the SKRUB first.

Check out some of these pages on HF. Pay very close attention to the ability of HF to do really bad damage to flesh. Such damage not showing up until a day later. Hydrofluoric acid - Wikipedia

Also check out the chemistry of the reaction of HF with glass. Wet chemical etching of silicate glasses in hydrofluoric acid based solutions - Springer


Wow! Just read your blog Henry and I plan on rereading many times!! I guess my guardian angels have protected me from lawsuits by my customers for further damaging their glass, yet I’m sure that the fact that their glass was already damaged would play a role in protecting me, but being sued by a commercial business I’d probably loose a suit!! Anyway, is your SKRUB the same as SMS and silica powder which you sell at $20/lb?? I think I understand from your blog that SMS is TSP with Dawn?? Also, are there any non-acid commercial removers that you recommend such as MineralX??
And lastly, is there any way I could reverse the damage that I did with the hydroflouric acid?? Thanks ahead.

I use sodium hydroxide (in the form of 5 minute oven cleaner) along with a white scrub pad, for screen burn/oxidation. I don’t do many jobs with heavy screen burn, though. If I did more, I would definitely move toward safer alternatives- something I should consider doing, anyway.

I’ve got some of Henry’s SKRUB product- cool stuff. It works nicely, but I had never thought to use it for this sort of application. I’ll have to remember that in the future.

Henry has been awfully tactful in the way he’s presented this info. But I hope you don’t miss the point. [B]Stop using CC on glass!!![/B] It’s causing “collateral damage” to solve a problem that can easily be solved with products that are safer for the glass and/or your own body. The fact is, you have been using a damaging product on the (sadly misguided) recommendation of someone in a window cleaning supply warehouse, who may or may not have known much about glass. And how many years ago did they make this recommendation? Knowledge and best practices change over time. CC-550 should have no place in glass cleaning, today.

Definately didn’t miss his point, if you read my comments about suit you would see I took it very seriously! I actually realize now that CC or rather the 1% hydrofluoric acid in it literally burns off the screenburn deposit then continues to actually burn the glass underneath! Light Bulb in Hydrofluoric Acid (HF) - YouTube

I’m very angry at how I was mislead and sad about the damage I did to customer’s windows along with removing the original problem and am very lucky to have not been sued and wish I had stopped using it years ago, which I did by switching to One Restore, but that appeared too toxic by odor. I almost feel that Winsol should be sued for making a product that damages glass even when used following manufacturing directions. I have been using CC for prob 8 yrs. Even looking at the current DSC catalog p .60-61 they rate Light to Heavy Duty Hard Water Stain Removers and Oxidation removers with Bio-Clean as “Lightest Duty” and One Restore and Crystal Clear as “Heavy Duty”. So CC is still pushed by suppliers as a solution but as I mentioned earlier about 5 yrs ago when I asked the manufacturer, Winsol about damage to the glass itself they denied that damage could occur or any distortion/shimmering/burning effect that CC does. So I am definately going to find out how to safely dispose of my remaining CC and use safer products, including Henrys’. (I will mention that I started using 0000 steel wool then A1 and both together. Wish I knew about safer solutions sooner but I plan on moving forward with new and correct information)

Alan and Alex,

Very well said. Right on spot!

I have a very interesting story to tell. Next time I get the time. Gotta move into the shower and get out. Don’t know where yet. But I gotta get there.


[MENTION=6699]cheetah[/MENTION], sorry if I came off a little strong there. I actually began composing my message before you made your reply to Henry, so I didn’t see it until after I posted my message. I guess I also wanted provide a warning to other readers, about the dangers of HF on glass.

But I am very sorry if I caused any offense :frowning:

Thanks for that Alex. But I do have shame and guilt for continuing to use CC knowing that while it helped resolve the initial problem that it created a second problem(yet the distortion the acid causes is not near as severe as a clouded window covered with screenburn). Just had a great conversation with Mike, owner of Detroit Sponge who knows and highly regards Henry. Mike was helpful in telling me that the customer came to me with a serious screenburn problem and I did use the only solution I knew despite knowing and often telling the customer before that there is a shimmering/distortion side effect yet the window would be much clearer than before. (Interesting how shame and guilt can lead to depression/anger and Mike helped to reduce my shame by his patient listening and understanding) Mike also wanted Henry’s information so I sent him Henry’s email and blog address. I’m very impressed with Mike’s window cleaning knowledge and their new catalog and will buy more than just their used huck towels which I found to be less used and needing less prewashing to be absorbant than other suppliers. I further discovered that my isolation in my business despite being successful for 13yrs is a partial cause of this continuing use of CC and I see the value of being on your forum or any forum. I have put off joining the WCRA for years but realize how others can really help prevent similar problems and problems in other business areas.


I was looking at your video and realized this demonstrates precisely the reason for the banding and orange peal effect that I discovered many years ago. I have described a couple tests for HF in my blog that demonstrate the same results as this light bulb test. Really fun stuff. But again, don’t try this at home. HF is very bad stuff.

Regarding my story. I was called in many years ago to a building with mineral deposits on some first surface pyrolytic windows. Probably PPGs Solar Cool Silver from the eighties. We had rainbows. I did know about HF and scratches at this time. So used a “safe” commercial product based on abrasives and sulfamic acid. At the owners approval I cleared a small spot on one window. A few weeks later they called me back in. Brought me around on the inside to that window. With the sun shining inside I could plainly see a small patch of very intense scratches. They could not be seen when I did the test. What happened was the building owner/manager had called in a window cleaning company that likely used HF or another wonder product based on an etchant. Which had cleared all of the windows. Over fifty of them. But also magnified by a factor of fifty any scratches in the reflective coating. No matter how slight. I also discovered that these magnified scratches were not very easy to see from the outside. But when looking out in the bright sun they were a glaring sore. All of this I put together after I left that day. After I discovered that HF and other etchants will also degrade a pyrolytic surface;…permanently! Most times this cannot be detected the first time. But when the spots return (and they will), and the wonder product is used again, it can somewhat strip off the coating. Or when an otherwise safe superabrasive compound is used the same reflective coating can be stripped off.


What this tells us since we never know what kind of work has been done to the windows or even shower doors;…we must have some kind of a disclaimer in place before we start. Otherwise who knows what we might uncover. Check with Bumblebee about this. He will tell you all of this and much more. Thanx Alan for your VERY humble attitude, thirst for knowledge, and valuable contributions such as that video. You are a great asset to our community!


Just read your message and story. Mike at Detroit Sponge also strongly suggested a disclaimer beforehand. He also mentioned a “clear and custody clause” on a liability policy that assumes the professional knows what he is doing and will not scratch the glass etc. Therefore, liability ins. may not protect the window cleaner??? Similar to your story are scratches from builders/contracters/brickmasons who scratch the glass to remove the mortar then after the window cleaner removes the dirt the customer sees the scratches for the first time.

Really appreciate your time and explainations because hopefully this is not all about me but may help others. For my customers with screenburn, CC was a solution of the lesser of two evils, ie remove the cloudy screen burn etc. for the lesser visual problem(side effect) of shimmering in the sun, or replacing the window. Now I know one of your products or another similar one will remove the problem without side effects. Mike at Detroit also emphasised following exact instructions and doing a test window. I’ll definately be contacting you for your products now that I know there is a solution that is not the lesser of two evils!!