Testing IGs For Negative Pressure Deflection

I finished a job today that exhibited very pronounced negative pressure deflection.  Especially the very skinny (about 14 inches wide) insulating glass units were very low on argon.  And yes, these were Anderson windows.  All of them.  Some were worse than others.  But all of the IGs demonstrated NPD.  If you want to know more about this problem check out my post on defective argon units.  Then go to the article referenced and read it.

The method for testing is very simple.  Just take your trusty six inch razor, soap up the window with some good sudz, then run the razor vertically straight up.  If there is even a slight problem with NPD the razor will miss some of the middle.  The more soap left in the middle of the swath the greater the effect and the more problematic the window.  Today I observed a virtual 'no contact' in the middle.  Just the two tips of the razor made contact!  Of course when I turned the razor and ran it across the window horizontally from left to right, it left no soap at all.

So there you have it.  It really doesn't need to get any more high tech than this.  If you show your customer this and relate the stories of those people who experienced the implosions, you will get attention.  Cuz you see.  We don't just clean windows.  We inspect them too.

Written by Henry Grover Jr

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Hydrophobic/Hydrophylic Balance

If you were to wet a brand new clean window glass surface with pure water you will notice that the surface is not equally funtionalized.  The water will sheet in places of the same plate and bead up in others.  This is not necessarily because there are contaminants unevenly covering different areas of the window.  It is likely because the physical integrity of the near surface is different.  The more 'rough' a surface is the more it will soak up and hold onto water.  Water will form larger beads when it condenses as fog on the surface too.  So the more rough a surface is the more hydrophylic it is.  The opposite is also true.  The more smooth the surface the more hydrophobic it is.  Condensed water or fog will also form smaller beads when looked at through a thirty power handheld lighted microscope.  You can prove this by polishing one side of a mirror plate with a cerium powder of five microns particle size, and then the other side with an aluminum oxide of 100 to 400 nanometers.  You will be able to feel the difference with your fingertip.  In both cases the chemistry of the surface is exactly the same.  The only difference is how smooth each side is.  The side polished with the submicron/nanometer scale aluminum oxide will be much more smooth than the opposite side polished with the cerium oxide of five microns.

Now.  What does this mean to a window cleaner using a water fed pole?  Simply that the results will be different from one window to the next.  Also.  When we choose an inline chemical to functionalize the surface as we clean, it would be best to choose one that will effect the correct balance between hydrophylic and hydrophobic.  This is because of two reasons.  First we do want to functionalize the surface equally across every square inch.  Second water will sheet best from a balanced surface.  If the surface were super hydrophylic it likely wouldn't sheet at all, but would rather cling to the window leaving a light film.  Also the very best hydrophobic surface is not superhydrophobic so little beads of water will form.  It is therefore more time consuming when cleaning an ordinary hydrophobic surface with a water fed pole.  The very best functionalized surface for the WFP user will be both hydrophobic and hydrophylic.  This balance can actually be measured by measuring the contact angle of a drop of pure water.  Also.  The eveness of the 'new' surface can be analyzed by fogging the entire window.  You will be able to easily see at a glance the pattern. And to reiterate the more hydrophylic surface will have the smaller water drop when the window is fogged.  By looking at the size of the water drop on the new surface under a microscope it is possible to quantify different chemical treatments to find the one that works the best.  Or at least to be able to label them from most hydrophylic to the least.  Then to choose the one that we prefer.  Almost like someone chooses a soap/cleaner depending on the level of suds action, and glide.

Written by Henry Grover Jr

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Creating Alkaline Water Via Resin Exchange Chemistry

Once you have reduced the TDS down to 0, and you now have totally pure water;...where do you go from there?  Why not use a resin exchange medium to alter the hydronium/hydroxide ion balance to raise the pH to a figure higher than neutral? Window Cleaners have already experienced fascinating results cleaning glass with ultrapure water with a very high pH.  Why? Because most of what we are removing from window surfaces are acidic.  Alkaline solutions will neutralize such contaminants.  This is how surfaces are cleaned.  Mineral deposits (hard water spots) are composed mostly of silicates. Which are alkaline.  That is why manufacturers have created products based on acids to remove them.  So.  Why not use another exchange tank to remove the hydronium ions from your ultrapure water making it a naturally powerful cleaner? What do you think of this?

Written by Henry Grover Jr

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Removing Mineral Deposits With Diamond

Diamond is the hardest substance on earth.  Well almost.  The water molecule might be even harder.  But for practical purposes it's hard enough.  And despite the extreme value of natural diamond gemstones, it has a greater value as a synthetic material used by machinists.  It might even have an unsuspected value to us.  For quickly and efficiently removing hard water deposits from window glass.

I will never forget my 'house on the hill' down in Amherst.  The windows had been damaged by a solution of sodium carbonate and sodium metasilicate.  A white haze which couldn't be removed with anything.  Except diamond.  I used a 5 micron compound in a syringe with Bounty paper towels.  No other compound worked.  Not even the acid based 'wonder products'.  What I personally find fascinating is the fact that diamond compounds don't shine like this in all cases.  Most of the time they perform equally as well as a compound based on a cerium or even a plain optical silica around five microns average particle size.

Another time I was working on sprinkler stains which covered dark glass.  No compound worked.  Even diamond compound with or without machines would touch these stains.  But a 'water wheel' based on a system of hardplastic nubs which were loaded with 5 micron diamond particles knocked it off in very little time.  All I used was water.  The only problem was the wheel left millions of very fine barely noticeable scratches.  Such were unacceptable.  I never continued working on this technology until now.

The technology of superpolishing glass with diamond loaded plastic is quite common.  There are many products out there.  The trick is finding the exact one that will do the job and not leave any scratches.  Then creating the wheel that will work best with this material.  This is one of the projects that I am currently working on.


Written by Henry Grover Jr

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Cleaning Glass with Sodium Hydroxide Revisited

This post was originally written many years ago.  Since that time it has received a great deal of attention.  For that reason I have decided to go back again and update it.  You will find pictures and a very enlightening video here.  Keep coming back to this post because there will be a great deal of additional information added over time.  Especially in the way of scientific/chemical knowledge and the results of some landmark experiments with a focus on visible etching of glass, deep cleaning techniques, and phobic/phylic conversion technology.

Over the years I have been personally fascinated by certain chemicals and the application of these to the practice of routine cleaning and restoration of window glass surfaces.  Sodium hydroxide is not the least of these.  But is one of the most interesting!

Has anyone ever worked with oven cleaner to remove staining from aluminum screens?  It works really well!  Sodium hydroxide has a voracious hunger for certain metals.  Such as aluminum that has leached from screens.  It will even eat up soda lime glass in minutes.  At the right temperature and concentration.  

Did you also know that restaurants use a product based on this chem to clean the grease off their grills?  Did you also know that it is used at farms to completely liquify dead animals?  Also it is used at 100% concentration in the form of crystals to eat up hair in household drains.  Furthermore it is used in food products. It has even been used as an ingredient in certain food products.  So why not clean with it?

OK.  So I went out and picked up the 100% dry crystals at the hardware store.  It cost me about eight bux for sixteen ounces (one pound). Here is a picture of it.

I had a pizza/sub shop to clean that I was called back into after at least four years.  Use your imagination.  It was bad.  My cleaner was worse.  It ate right through everything.  There were  a few windows that hadn't been touched at all for several years. They looked like they had a dark solar tint on them.  So I needed to scrub a little with 0000 steel wool.  But when I was done that glass was crystal clear.  Of course my skin was black and dried out.  Next time I will use gloves.  In fact let me say this.  Sodium hydroxide will really burn your skin bad.  And you should never get even the smallest amount in your eyes.  So gloves and goggles probably would be best.  It will make pure water really hot if you put enough in a cup.  When mixing it is best to use plastic cups and containers.

In practice I discovered that rather than a teaspoon per gallon I could get away with ONLY 1/8th of a teaspoon per gallon;...or less!  I didn't say a tablespoon.  I said a teaspoon!  I use this concentration for routine cleaning at a pizza/sub shop.  Not restorative deep cleaning as the one I just described.  Restoration grease stripping requires higher concentrations.  Remember to always used rubber gloves too.  Keep your hands dry.  As an interesting additional thought I was wondering about the use of super-abrasive plastic abrasives along with sodium hydroxide cleaning solutions.  Also other super-abrasives.

So here are the questions.  Since the technical literature that I have read indicate quite plainly that very strong alkali solutions will etch glass, will a much lighter solution of sodium hydroxide also cause etching?  This video also referenced above shows how sodium hydroxide will totally eat soda lime glass under the right conditions.  Much milder solutions have been used to "deep clean" glass surfaces to remove all organic molecules so that window glass becomes completely hydrophylic.  I will be doing some rather interesting experiments with my "white crystals" over the next week.  And will be progressively updating this post.

We also really need to know if very mild cleaning solutions will cause the same etching effects that 1 percent solutions of hydrofluoric acid cause.  To discover the answer to this question I will be performing the two different tests I have developed here for acids.  It is indeed true that even water itself is quite capable of etching glass.  But very slow and under conditions other than routine cleaning.  So when testing cleaning/restoration solutions of sodium hydroxide we should test the concentrations used in each.  Again it is obvious from the video referenced in this post if we use much higher concentrations at much higher temperatures, (such as a hot summer day) than we absolutely will etch glass. 

When I tested the different acids used in so called commercial restoration products, I tested them at the concentration that was suggested they be used at.  Straight out of the bottle.  The MSDS gave me the name of the acid each was based on and the percent of concentration.  I also tested them at the temperature they would be routinely used at.  Time is also a condition.  Certain acids such as hydrofluoric and sulfuric acid will show etching in as little as thirty seconds.  It is even possible to create visible distortions of glass surfaces in only thirty minutes.  What about when the solution puddles at the bottom of the window and remains there.  This can easily happen on overcast cool days.  It is also true that the glass might be dark and very hot from the sun.  Both the composition of the glass and the temperature could easily contribute to the visual effects of such acids (etchants).

There are other questions that should be answered.  Such as the problem of the yellowing of white vinyl window frames and vinyl siding.  Oven cleaner will yellow out white vinyl in seconds. Especially on a hot day.  It is based on a 4% solution of sodium hydroxide.  At what concentration is a sodium hydroxide routine cleaning solution safe to use around white vinyl?  To answer this I might heat up some water to about 180 degrees F.  Put in a certain amount of crystals.  Mix it up.  Then do the dip.  Dunk a strip of white vinyl used on window frames.  Leave it in there for at least five minutes.  Remove and inspect in bright sunlight.

White vinyl isn't the only other surface to look at here.  There are in practice many other surfaces out there.  The only way to know in advance which chemicals are safe to use around any surface  would be to test your cleaning solution on that surface.



Written by Henry Grover Jr.

Please email me directly with any questions you might have about this article and future products I am working on or you would like to see developed.

henrygrover222@gmail.com