The GTC Newsletter

Glass Destruction Via Weld Splatter

2006-07-13T07:17:00.000-07:00

Simply put the temperature of the sparks that come from weld or even metal cutting wheels, are quite hot. Hot enough to melt glass surfaces. There has been a great deal of damage done by people all over the world working on metal close to glass windows and glass railings. Usually they think these are just little black or brown spots that the window cleaner can just "pop off"! But not. If you take a single edged razor blade and place the pointed tip into the "spot";... you will immediately learn the truth. That "spot" is actually a little hole with some metal residue where the spark melted its way right into the glass surface. Your blade tip will sink in and not move. This type of damage can not be easily fixed. Almost all of the time it is impossible. Since sparks fly, and there are a lot of them, the entire surface area is usually damaged. I suppose if there were just a few or several holes that weren't that deep they might be able to be polished away. But this is just a dream. Anyone working close to glass with metal cutting or welding equipment should take every precaution by protecting the glass. Otherwise irrepairable damage will happen. Which could easily cost tens of thousands of dollars in glass replacement. This won't make anyone happy. This information is brought to you by your S.M.A.R.T. Window Cleaner.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Finding a S.M.A.R.T. Window Cleaner

2006-06-26T07:28:00.000-07:00

If you are looking for a "Professional Window Cleaner", don't pick the first company that swings a squeegee and advertises in the local paper. If you do you might end up with scratched or etched window glass. They need to be glass cleaning surface techs. This means they must not only be able to clean a window without leaving streaks. But also should be able to identify what type of surface they are working on; whether there is fabrication debris embedded in the tempered glass; has someone damaged the surface before them; and what restoration products/chems are safe for the window (will not chemically attack/etch, or scratch). Regarding the issue of fabrication debris. I have written an entire post in this blog on the subject. It has become a problem, as tempered glass is being turned out with surfaces that cannot be scraped or else the microfines will scratch the glass. Not the razor. So how does one deal with such a problem? Further, windows are much more advanced then they were just a few years ago. So they are much more costly. Companys have created all types of Low E coatings which have been applied to those surfaces we come into contact with, and those we cannot touch. These are called Super Windows. But there are Smart Windows too. Such as electrochromics and suspended particle device. Some of these windows can easily cost over fifty bux per square foot to replace. Currently companys are working on ways to make windows photovoltaic. This means instead of simply being solar filters, they are being converted to sun powered electrical generators. Also, have you ever heard of Self Cleaning glass? This is a titanium dioxide coating which is photocatalytic ( powered by UV radiation), and hydrophilic (water loving). It is supposed to break down dirt with the energy of the sun, then rinse it away with the rain. How does one clean/maintain such a surface? Also, if it gets covered with different types of post construction debris like paint overspray;... how does one remove this without doing harm to this new high tech surface? So we can see that windows do in fact require window cleaners to be Surface Maintenance And Restoration Technicians. We need to be S.M.A.R.T.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

The Destructive Power of HF

2006-06-24T09:27:00.000-07:00

Hydrofluoric acid (HF) eats up most hard water spots based on a silicon chemistry with a voracious appetite. It is for this reason that commercial products based on HF have been created for clearing window glass damaged by ground water in sprinklers, and concrete efflorescence. Each can leave behind extreme mineral deposits based on a spiked silicon fingerprint. At times it might even appear that no damage has been done to the glass during the "restoration" process using HF. However looks can be decieving. The simple facts are that whenever an HF solution of as low as one percent makes contact with glass for as little time as thirty seconds, a chemical reaction takes place. From my own observations alone I would venture to say this is a stage two dynamic etch. That means that the silicate/silica matrix of the glass has been dissolved and dynamically removed, leaving behind a new surface. Which surface is much more rough on a microscopic level than that of brand new glass. But you won't need a microscope to prove this. Just lightly run your finger across this new dry surface. The surface will also cause pure water to sheet out very well without leaving hardly any drops.
Here are a couple of experiments you can do yourself in your own kitchen to prove to yourself what I have said is true. Take a small three by three inch slide of window glass, and dip it in a cup of HF at only one to two percent concentration. Only emmerse one half of it. Leave it there for a minute. Remove it, rinse it, and dry it completely. You will notice the "water line". This is a line showing where a stage two dynamic etch happened. Next take a six by six inch mirror square. Create a good four by four inch patch of scratches in the center. Now apply only a one to two percent solution of HF to one half of your scratch patch for thirty to sixty seconds. Rinse quickly, and dry. You will see that the scratches which made contact with the HF solution have been severely magnified. Another interesting test involves drawing a letter on a mirror plate using a paint marker from Faber Castell. Once drawn rub a dilute solution of HF over the entire area untill the paint has been removed. Now rinse and dry. You will be able to see where the paint was. There will be a clear distortion of the glass only where the paint was. So you will still be able to make out which letter you had drawn. I remember visiting a building once where some HF had been used to remove long drip lines of a concrete silicone sealant from some dark glass. The sealant was gone, but there were long band lines left as a clear distortion of the glass. Further there was a clear orange peal effect showing where the hard water spots were. If you drive down the highway and check out some of the older glass boxes that have had HF used on them for many years, you will be able to see this type of distortion. Any type of waviness on glass plates is much easier to see from a distance. Now in the case of scratches. How do you know that someone has not been there before you and removed the previous spots with a crude abrasive? You will remove the second batch of spots, but in so doing you will also severely magnify the scratches leftover from the first time. Not good. Since the owner (who never seen the scratches before) will now think that you caused them to begin with. I can go on. But hopefully this info should help anyone who reads this, to understand why I would never suggest that anyone use HF on windows, unless they are plexiglass. Then there are other dangers to contend with too. It is not a forgiving chemical. Further;...if you do any experiments with it always use adequate precautions. Gloves, eye protection, etc. Since there are some serious health risks involved too. My advice is always to stay on the side of caution. I hope no one misunderstands me. My intent has never been to do anyone harm. Also, ultimately it will be the Window Cleaner that has to make a decision as to what they will use to remove anything from the window. It is your company and you are the commanding chief.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Hard Water Spot Removal Techniques

2006-06-18T12:37:00.000-07:00

Hard water spots come from hard water drops when they evaporate. Hard water comes from the ground (sprinkers or the garden hose), and concrete/brick efflorescence. It is called "hard" because of the total dissolved solids (TDS). The key word being solids. Basically these solids are microscopic pieces of rock or minerals. So another name for hard water spots is mineral deposits. When the water poofs away in the hot sun, these little pieces of rock are left behind. Most of the time they are based on a silicate chemistry. This is a silicon molecule that includes the elements oxygen and some metal (calcium, sodium, magnesium, etc.). Window glass is based on a silica/silicate matrix. Silica is silicon and oxygen only. Most of the silicates in glass are based on calcium and sodium. Since the chemistry of most hard water spots is very similar to that of window glass, they usually form a good bond. Another reason they bond well is size. These little pieces of rock are around two to five microns across most of the time. Also the microscopic pores of window glass are about five microns. So these mineral particles "fit" very well into the micropores of glass surfaces. And there they stick! As we know all too well.
Most if not all of the hard water spot removal products on the commercial market are based on acids and or abrasives. The idea is to either chemically eat up these little pieces of rock, or abrade them away physically;...or both at the same time. I've always been in favor of the very last option. If the spots are based mostly on a silicate chemistry, then the only acids that will eat them up are those that will eat up the surface of the window glass. Here I am talking about mineral acids. So called because they are not based on a carbon chemistry like glyconic acid. Some common mineral acids that work good at dissolving mineral deposits based on silicates, and etching glass surfaces;... are hydrofluoric, sulfuric, and ammoniumbifluoride. If the spots are based almost entirely on calcium carbonate or sodium carbonate;... mild acids like sulfamic, acetic, citric, or glycolic will work well. Then if you add a polishing powder such as an optical grade silica, cerium oxide, or aluminum oxide;...you will have the best of both worlds for a real quick fix. I never advise the use of mineral acids which are glass etchants. If the spots are based almost entirely on silicates, then the only way to deal with them effectively and safely is by means of a refined optical grade polishing compound or slurry. Any milder organic acids at this point are a simple waste of time and money. A few quick tests will determine in a matter of minutes exactly what the nature of the problem is.
Now while there are many different hard water spot removal products out there on the commercial market, I strongly urge extreme caution. Many of the manufacturers of these products have little knowledge of the technical nature of the problem;... along with the products and techniques necessary to safely and effectively solve it. Education is critical. Anyone performing glass restoration needs to be completely educated. Otherwise they could waste entire buildings, and bring on themselves tremendous lawsuits. I have been called in to consult on several such. This kind of education is one of the reasons I have established this blog. There will be more articles on hard water spot removal techniques posted here in coming days.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Micronized Cleaning Dispersions

2006-05-28T19:16:00.000-07:00

Synthetic detergents along with certain cleaners such as ammonia can only do so much in removing contaminants such as greasy finger prints. By adding certain silica particles to your cleaning solution it becomes possible to "scour" the microscopic surface of glass without doing harm to it. All that is needed is a handfull of powder to about three gallons of soapy water. Even a mild soap can be used. Here the soap such as a cationic surfactant is used primarily to add glide to your squeegee blade. Not so much to clean. The silica particles which are about the same size as the diameter of the pores of a glass surface will do most of the cleaning. They will effectively scour the surface. Reaching deep down into the pores, digging out any and all grease or any other contaminant. The zeta potential isn't great enough to keep these particles permanantly suspended. We would have to drop down to the nano level for that. But they will stay suspended for a few hours while you work with your cleaner. When working you will notice that the color of the water will turn a slight white. But this is good since it lets you know that your particles are in suspension where they will be most effective. When you dump out your bucket there will be some powder left at the bottom. But not much. This however is the reason why no one has commercialized a product like this. Although it might be possible to add the powder directly to the pure syn-det. There it likely will remain in suspension much longer. A time limit of six months is required for all commercial products. This is called the shelf life. Particles are also chemically treated to help bring them into a water based suspension. In fact, if they have not been properly treated, they will not go into suspension at all.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

GTC DVD Tutorials

2006-05-25T06:41:00.000-07:00

I will begin production of a line of DVD Tutorials in July. I have contracted with a company experienced in video productions to create a specialty line of teaching aids to help certain ones in the Window Cleaning Industry understand and best perform glass surface restoration. The first one entitled "understanding glass stains" will be free. It has always been my goal for the last fifteen years to write and create other teaching aids. To learn and create custom products for solving problems and expanding our current means of earning a living. I want to give back to the industry just some of what it has given to me. There might be times when the formulations that I develop will be too involved. Also they will have shelf lifes of one day to only a week. In this case it will be necessary to establish a network of short order toll mixers around the world to help us out. Or at the very least to train individuals in different companys by means of DVD exactly how to put together such formulations. I know this sounds complicated and intense, but I do believe that the window cleaning industry will continue to rise and learn. Also there will be chosen companys that will take advantage of such custom products. These are the ones that will take the lead in the technology of window glass cleaning, restoration, and preservation! I am certainly not the only one dedicated to this. There are others within our ranks who are working hard. Forming new associations, building machines, creating teaching aids, setting up web sites, and on and on. These ones we all know by first name. I have nothing but good things to say about them. And I am sure they will help me on my journey too.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Artificial Hard Water Spots

2006-05-22T17:48:00.000-07:00

Hard water spots are otherwise called mineral deposits. They are based on various metal salts. Also silicates. It is the silicates which are the most difficult to remove. These are based on a silicon chemistry, and will bond exceptionally well to a glass surface. Usually the only acids that will dissolve silicate deposits are those that chemically attack the glass surface itself. Here we are talking about acids such as hydrofluoric, sulfuric, and ammoniumbifluoride. Many of the hard water spotting problems out there are due to silicates. These come from ground water, and from concrete efflorescence (or leaching). The micropores in the surface of concrete building facades soak up rain water (which is acidic). There the rain reacts with the minerals in the concrete bringing them into dissolution. The now mineral laden rain water leaches out of the micropores, down over the glass. When the sun comes out the drops evaporate, leaving behind the minerals that were formed when the rain reacted with the concrete. These silicates are usually very high in silicon. I remember seeing an elemental read out one time of the various elements present in a sample that was scraped off a window. The silicon spiked off the page. The reason I am going over this information is to show what type of stains are chemically much more likely to really stick to the glass. This is the type of stain that we would like to duplicate on a microlapped surface in order to test various glass protectants to see which one works best at keeping the spots from locking on. Simply put;...silicates. Now if one takes what is called water glass (sodium metasilicate), and mixes only several tablespoons in a quart of water, it is possible to create your own silicate deposits. All you have to do is microlap a window that gets direct sun, then sprinkle your formula on the glass. Spots will form when the water drops evaporate. At times they will stick instantly. Or some time in the hot sun might be needed. Either way, you have created what I arbitrarily call "artificial hard water spots".

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Engineering Stain Resistant Glass

2006-05-14T09:07:00.001-07:00

The first step in engineering high quality stain resistant glass surfaces involves microlapping to remove all mineral and organic deposits. The windows might be covered with mineral deposits from concrete efflorescence, or ground water from sprinkler heads. Either way it must be removed. The best polish is one based on an average particle size of aproximately four microns. This is the average size of the surface pores of commercial glass. What is interesting is that minerals in water are actually particles of the same size or smaller. So they fit very snugly into these micropores. So before and after we are left with a surface of about this degree of roughness. Usually the surface is even more rough after microlapping. Which means that it is more prone to the reformation of hard water deposits. Then when they return they will stick even better. Althoug I don't think you could call that better. Any hydrophobic sealant/protectant applied at this point will definitely help to keep such hard water spots from sticking really good next time around. Although once the polymer has been degrade by the ultraviolet radiation of the sun, these micropores still have their mouths open wide to accept more mineral deposits. So stick again they will. In theory, if we were to nanolap after microlapping, then seal with a protectant, we should attain a much more stain resistant surface. The glass will be naturally stain resistant owing to the fact that it will not have any gaping holes waiting to get hold of any little pieces of rock. Also it will have a hydrophobic polymer surface to push away any mineral laden hard water. Such a hydrophobic surface will also help to keep the new nanosurface from undergoing the weathering process. This is a natural stage two dynamic etch that happens to all glass surfaces over time that are exposed to acid rain. I am currently working on a product based on a dispersion of nanocrystalline cerium particles imersed in water with an organofluorosilane sealant. So that we can nanolap and seal simultaneously. This might be a little tricky for most to formulate on site, so I will be looking for manufacturers to work with me in bringing it to market. Any takers?

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Nanoscale Polishing of Window Glass

2006-05-13T16:00:00.000-07:00

The surface of window glass is rough down to an order of about five microns. The micro pores of the surface of window glass are on the average this big. So when we polish windows using a cerium slurry with a similar particle size, we can only hope to attain this degree of roughness. Which is average. Five microns is five thousand nanometers. It is now common practise to polish glass flats used in optics down to a roughness of twenty nanometers. That is 250 times finer than what we are accustomed to. Since glass is water loving, (hydrophylic) the tighter the surface the more it will bead water. The rougher the surface the more it will hold onto water forming a film. So by super polishing glass on a nanoscale, we can create a natural rain repellant that will help to prevent the natural process of etching. In short, get rid of the craters and holes, and make it smooth.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Fab Debris & Scratched Glass

2006-05-11T06:36:00.000-07:00

Fabrication debris on tempered and heat strengthened glass has become a major problem. Unfortunately general contractors, window manufacturers, and building owners know very little to absolutely nothing about it. Yet this type of defective glass can be the result of the loss of millions of dollars in wasted windows. Anyone can inadvertantly come across this type of glass and do damage. The big debate going on now is whether to use or not use razor blades in cleaning tempered glass. Simply put razor blades are NOT the cause of this problem. It is the fabrication debris left on the surface of the glass during the tempering or heat strengthening process. Any extremely small pieces of glass which have contaminated the rollers of the tempering oven can be picked up by the glass sheets. These particles come from the glass when it is scored and cut to size. They might not have been completely cleaned from the glass before tempering. Also they might have contaminated the rollers in the oven which have not been maintained clean and in good condition. Either way they wind up permanently embedded in the surface of the glass as it passes through the oven. When the glass is cleaned there is always a risk that they might be dislodged in some way and dragged across the window. When this happens scratches result. They can be dislodged by plastic as well as metal razors. They can be dislodged by plastic wool, steel wool, or even felt pads. Thats right! I talked with a window cleaner the other day who specializes in glass restoration. He removes stains, and scratches from architectural glass surfaces. The commercial machine he uses is very advanced. But he told me that he recently turned down a job where the glass had been scratched by microfines/fabrication debris. Why? Simply that any loose particles left on the glass could easily get in between the polishing pad and the glass surface causing millions of additional scratches.
Fabrication debris is a problem that needs to be dealt with. It first must be recognized. That is why I am writing this blog. But since this type of defective glass is already out there it needs to be understood that only professional window cleaners who have an intimate knowledge of this problem should be hired to clean windows. They need to know where tempered glass is, and how to quickly learn if they are working on a defective surface. Many professional window cleaners have even seen fit to have a waiver signed. Because no one has decided to put a label on this glass marking it clearly as defective, we are all left to own own devices in dealing with it. We do our best but everyone has limitations. And we are not the ones who are responsible for this problem. We are actually doing everything in our power to educate as many others about it so as to prevent scratches on glass. We are working hard to stop scratched glass!

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

Window Glass Protectants

2006-05-07T17:00:00.000-07:00

Window glass protectants are chemical sealants that are used to treat the surface of window glass. These are usually hydrophobic which means they repel water. So rain will bead up on them. As opposed to spreading out. Protectants form a barrier between water and the glass surface. Also between any mineral deposits that are left behind when water evaporates from the surface, and the glass. Such sealants protect in at least three ways that I can see. First they gaurd against scratches. Only certain ones work very well at this. They will gaurd against hard water spots (mineral deposits) from sticking very strongly to the surface. They will also protect against the weathering effect. This is a type of natural etch that happens as acid rain literally eats away the surface over much time. Now not all glass sealants are created equal. Some just set on top. Thay will wear off in a week or a month. Ultraviolet radiation seams to have an effect on their longevity. There exist protectants that are true S.A.M.s. Otherwise know as self assembling monolayers. They form a covalent bond with the glass, and will not react with plastic or metal. Such protectants are usually polymers based on organic/silanes, siloxane copolymers, teflon (ptfe) based organic (carbon) silanes, and even diamond. Or so I have been told. The bottom line however dispite all of the advertising, is how well will they work for your purpose, on your building? I have found the best way to answer this question is to set up different tests on the building in question, and wait at least six months. If you are dealing with scratches, you simply want to know if the sealant has worn off and is no longer effective. This you can test for. If you are trying to create a condition where all newly fromed hard water spots can be much more easily removed, again a simple test will tell this. I have found for example when dealing with screen stain from aluminum screens, that even a topical sealant if not in the direct sun will last for years. When it is time to remove the newly formed screen stain, just some four zero steel wool will very quickly knock it off. This it will do and still leave the sealant on. Whereas a more agressive spot removal product would remove both. So it becomes necessary to know what will remove the stain but not the sealant. There are techniques that can be used too for removing the stain, and applying more sealant/protectant simultaneously. I have developed certain custom products for this. Anyhow, in a day and age when scientists are experimenting with treating silica substrates with carbon nanotubes, we can expect the new hydrophobics industry to continue to advance. Such nanotubes that I speak of must be attatched to nickel nucleation sites in order to attain a very regular S.A.M. Then the top of the "trees" are capped with teflon. This technology was developed by some scientists at the Massachussetts Institute of Technology (MIT).

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com
www.gtcnews.blogspot.com

Residential Window Inspections

2006-05-04T17:18:00.000-07:00

It is absolutely impossible to correctly inspect windows before they have been professionally cleaned. The reason involves what is called insulating unit seal failure. When this happens the unit (which consists of two plates of glass separated with a small space and an inert gas in between) sucks in some of the air and with it water vapor. This condenses on the inside of the unit causing a slight cloudiness. The more vapor, the greater the condensation, the more intense the cloudiness. This effect is usually very difficult to detect when it first happens. It requires a trained eye, and of course a proffesionally cleaned window. Many windows in home might have already lost their seal. But no one would know. If you are purchasing a home, especially one with a lot of insulating glass windows, it would be in your best interest to request a professional that is familiar with this condition, to clean them. There are other problems that will show up under the trained eye. Such as gasing inside of the unit (not from seal failure). It looks very much the same however. Also I have personally seen rag marks, fingerprints, and much dust, inbetween the two plates of an IG (insulating glass) unit. Of course these are all sealed in permanently. Problems can result from the misplacement of the tin side of float glass. The low e coating might have been put on the wrong side when the IG unit was manufactured. Such coatings could also be damaged. If the low e coat is soft, it must always be located in between the two plates where it is protected. Because when it is touched, the mark left cannot be removed. This is why I have seen many thumbprints of different colors permanently left in between the two plates of an IG unit. Other problems include fabrication debris on tempered glass. This is a defective surface. Damage from scratches or hard water deposits. Various types of etched surfaces can also be a problem. Tempered glass can be extremely wavy from the tempering oven. All of these potential problems and more , can be detected by the professional window cleaner who has been trained by experience. Not your local home inspector.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com

The Four Stages of Etched Glass

2006-05-03T17:06:00.000-07:00

Glass is made up primarily of silicon, oxygen, calcium, and sodium. That is window glass. It is otherwise called soda lime glass. Glass can be etched with various chemicals. Three of which are sulfuric acid, hydrofluoric acid, and ammoniumbiflouride. There are three different effects I have noticed indicating an etch has occured. One is a clear distortion of the surface where reflections are changed. This can be in the firm of long lines. Where silicone sealant had run down prior to removal with a hydrofluoric acid based product. Or a type of orange peal effect showing where each hard water spot was prior to removal with a hydrofluoric acid based product. Another is a whitening effect that can also appear as a slight or very strong white haze. This can happen when the tin side of tempered plates makes contact with hydrofluoric acid. It can also happen when HF makes contact with a surface that has been severely physically abraded on a microscopic level. Then a third effect involves scratches. Which otherwise might never have been noticed. Scratches are usually severely enhanced (made much more visible). Scratches that were very slight but hidden by mineral deposits will always be magnified many times over when they are revealed after the HF takes off all of the mineral deposits. All of this is what I have observed in the field. These different types of etch fall into one of the four different stages of etched glass surfaces.
These are stage 1 static, stage 1 dynamic, stage 2 static, and stage 2 dynamic. Stage 1 whether static or dynamic, only involves the calcium or sodium atoms. These are usually replaced with the hydrogens taked from water. Stage 2 whether static or dynamic involves what is called total dissolution of both the moderator and builder matrix of glass. In other words, all of the atoms have been reacted with. If we are talking static the reaction byproducts have remained on the glass. In the case of a dynamic (in motion) etch, all of the atoms involved in the reaction have been removed from the surface. To apply. Most types of etch we observe in the field via the inadvertant use of glass etchants in restoration work are both static and dynamic. The whitening effect is static. But usually a dynamic etch has occurred as well. When scratches have been intensified, this is a static etch. When the clear distortions of mineral deposits have been left behind, this is definitely dynamic. If these distortions are severe enough, restoration of the surface might not be practical at all. But there are certain static etched conditions that are restorable. Especially if that static etch has resulted from vapors instead of direct contact with the acid. An interesting case in point involved a crystal glass shop. I was called in to identify and fix a white haze on the inside of every window in the shop. The man was moving out and feared his landlords anger. It turned out he was dealing with a vapor etch from the fumes of hydrofluoric and sulfuric acid. They use vats of both at extreme concentrations, and high temps. The acids release gases that travel through the air, and become acids again when they recombine with water vapor that condenses on the inside of window glass. This happens more in the winter because of the difference of the temperature between the outside and the inside. We were able to restore the surface without any signs of clear distortion (stage 2 dynamic). However, the amount of time necessary to accomplish the task was greater than this man wanted to give. So a quick job was done. One that was apparently acceptable to the landlord. I could go on forever with this topic. So I will sign off now, and come back to it later in another post.

Henry Grover Jr.
gtcnews@hotmail.com

Window Cleaning Solutions

2006-04-29T15:55:00.000-07:00

Window cleaning solutions are not all created equal. Usually they are based on certain synthetic detergent (syn-det) blends. Such are most times taken from nonionic, and anionic surfactant familys. Other times various hydrotropes are thrown in to augment the low molecular weight syn-dets. These might be sodium paraffin sulfonate or sodium xylene sulfonate. Other hydrotropes have also been added. I prefer cationics. Two in particular are a cocamidopropyl betaine, and a cocamidopropyl PG dimonium chloride. They give adequate glide for the squeegee blade, exhibit negative bleed (drawback or breakaway), produce enough suds for visibility, clean well enough for routine commercial work, and are very mild leaving skin soft and supple after a days labor. The nonionic family cuts through grease very well. But it will also strip the natural oils from your skin, leaving it dry and cracked. Not to mention some of the various chemicals window cleaners have used over the years such as trisodium phosphate (TSP), or a TSP substitute call sodium metasilicate. Some people have used sodium carbonate too. Which is a very powerful alkalie. Strong enough to strip paint off aluminum frames! The chems clean and give the squeegee rubber adequate glide by breaking down the surface tension of water. But this usually also creates a tremendous problem with what the industry calls bleeding. Where the solution will run right out from the windows edge. Syn-dets on the other hand give the squeegee rubber glide primarily by means of various alkyl chains. These are long chains of carbon atoms without a hydrogen cap. Such chains in theory act as a type of oil at the glass/rubber interface. A very thin film is left on the glass. Although it is completely invisible until a second film of fryolater oil, car exhaust, or cigarette smoke forms on top. This is just the beginning of what will be a long discussion of the chemistry and practical use of window cleaning solutions.

Henry Grover Jr.
Glass Tech Consulting
GTSForums@hotmail.com

Glass Surfaces

2006-04-28T06:21:00.000-07:00

Not all surfaces are created equal. Whether it be chemically strengthened, annealed, or tempered (toughened);...all surfaces are physically different. Sure the builder and moderator network might be the same. But the quality of the surface can be very different from one window to the next. Microfines, or fabrication debris is a very common problem these days. It results when the very small, sometimes microscopic, little pieces of glass left over from cutting the glass to size, are embedded in the surface during the tempering process. This happens when the glass is passed through the tempering oven in a semiviscous state. As it is soft, these little pieces of glass make contact and are literally stuck in the sheet. They might have been left on the sheet due to poor cleaning prior to tempering, or are left on the ceramic rollers. Once baked onto the glass they can be disloded by anything used to scrape the window clean. Even wool pads used on windows to remove scratches left by these microfines, can catch more microfines swirling them around at enormous speed, creating millions of aditional scratches! Simply put, this can turn out to be an enormous problem. Unfortunately it is usually a problem that the window cleaner has to deal with. If only more people knew about such poor quality surfaces, more might be done to solve it.
Fab debris can be small, or large. The fines can almost be large enough to see with the unaided eye. They can be small and large on the same plate of glass. Tempered glass is not the only glass that has a different surface. Even annealed glass can have a very rough surface. Not owing to fab debris however. Nonetheless it can be extremely smooth, or very rough to the touch. To check all surfaces I use a coin. Once the surface has been cleaned with a solution and a squeegee, I lightly run a small metal coin across it to feel for any fab debris, or just simply to check on how rough it is. If it is very rough, then it cannot be scraped. Other methods must be employed to remove wood stain, paint, silicone caulking, or whatever else might have got on the window during construction. The bottom line is very simply that not all glass surfaces are created equal, and so the methods used to remove contaminants, and clean them must be different also.

Henry Grover Jr.
Glass Tech Consulting
GTSForums@hotmail.com

Introduction

2006-04-27T16:44:00.001-07:00

GTC stands for Glass Tech Consulting. This newsletter will deal primarily with the chemistry, and nanotechnology of window glass cleaning, restoration, and preservation. Its main focus will be the tools, and chemical products used to enhance, rejuvinate, and protect the various window surfaces past, present, and future. This includes a host of different materials since various coatings have been used on windows. Also windows themselves have been made from materials other than glass. Further, even the glass itself can be quite different from one window to the next. It also follows that the surface of any material is chemically different from the inside of that material. All of these facts create an opportunity for much study, research, and ultimately learning. I hope all who read what I will be writing about find it informative, interesting, and of course practical.

Henry Grover Jr.
Glass Tech Consulting
GTSForums@hotmail.com