scratched glass - master window cleaners of america · 10 the issue of scratched glass and...

10 www.professionalwindowcleaner.co.uk

The issue of scratched glass and fabricating debris isperhaps one that many UK window cleaners will not beall that familiar with. However, it is a hot-topic in the USA,and all the indications are that it is set to become just asimportant for UK window cleaners, especially those whofrequently perform builders cleans.

So, what is the problem with scratched glass, and whyshould window cleaners know about it?

Who’s To Blame?Glass may become scratched at many different stages inthe construction process. Sometimes construction work-ers place their tools on windows, painters and plasterersmay try to remove spatters by ‘dry scraping’, and some-times just not enough protection is given to the pane dur-ing installation.

However, a contentious issue arises when apparentlyscratch-free glass is left marked after a window cleanerhas used a metal scraper to clean it.

Do Metal Scrapers Cause Scratches?In a word, No. But unfortunately it isn’t quite as simple asthat. Nearly all window cleaners have used a metal

scraper at some point to remove stubborn marks on win-dows, and of course have found that they do not causescratches to appear. However, in certain circumstances,using a metal scraper on new glass may dislodge micro-scopic pieces of glass debris (or “Fines”) that are leftbehind during the tempering process. If these aredragged across the surface of the glass by the scraper,severe scratching may result.

The question of liability in such circumstances is a con-troversial one. Is the window cleaner to blame? Or arethe glass manufacturers at fault? As the cost of replac-ing or repairing scratched glass can be very high, this isan important question.

MWCoA SeminarThis issue is such a hot-potato that U.S. trade associa-tion The Master Window Cleaners of America held aseminar to help educate its members about the problem,and how to avoid it in the first place.

PWC would like to thank MWCoA Executive DirectorJack Nelson for contributing the following article on thesubject.

For more information on scratched glass, visit:www.stopscratchedglass.comwww.scratchedglass.net

Scratched glass is becoming more of an issue for window cleaners everywhere. It’s aproblem that U.S.window cleaners have been battling for some time now,and it’s com-ing to Britain.

Scratched Glass

Friend or Foe? Metal scrapers are often (wrongly)blamed for scratches, especially for construction cleans

The cause of “Comet” scratches like those shown above isalmost always as a result of fabricating debris (the comet’shead) broken and trapped by the scraper, creating thecomet’s ‘tail’

MWCoA Seminar

PWC ISSUE 5 NEW IMAGES2 18/12/05 13:31 1

Dan Fields

(Fields

Construction

Services Inc)

presented the

seminar on

Fabricating

Debris &

Scratched

Glass

PWCMWCoA Seminar : Scratched Glass

11www.professionalwindowcleaner.co.uk

“I must be dreaming” This is thethought that first entered mymind on two occasions when Istepped into the window clean-ing Mecca that is the Ettore fac-tory, and Dan Field'sConstruction Company inOakland, California in October2005. I embarked on a 3,000mile journey via air to be treatedto all of the latest and greatestadvancements in the business.I also had the privilege of meet-ing some of the finest profes-sionals in the business.

Members of Master WindowCleaners of America (MWCoA)were treated to a tour of theEttore plant by the CEOMichael Smahlic. The tourbegan in a conference roomjust outside of Smahlic's office.He showed us the 1stsqueegee ever made. He alsoshared the story of how hisfather-in-law won a hat from J.Racenstein on a bet. If you goto the Ettore website, it really isan interesting story. A tour of theplant followed. We watched asrubber was cut, squeegees

were assembled, and every-thing was shined and boxed. It'sa very smooth operation. At theend of the tour, no one wantedto leave, but the factory hadalready shut down and we werethe last to be leaving for theday. So it was off to the hotel.We talked window cleaning nonstop from the time we gottogether for breakfast until weparted to our rooms for thenight.

Dan Fields presented the semi-nar. I have always beenimpressed with the wisdom andknowledge he exudes. Youshould see his operation! Heemploys 65 window cleanersand has about 30 vans and

Fabricating Debris &Scratched Glass Seminarby Jack Nelson, Master Window Cleaners of America

PWC ISSUE 5 NEW IMAGES2 18/12/05 13:31 Page 12


trucks running each day, has a10,000 square foot officebuilding and they clean 4,500new homes each year. If youever need to know anythingabout windows, for certain,Dan is the man to ask.

A seminar about windowcleaning is a learning experi-ence, but the learning does notstop when the seminar ends.In as much as a seminar is alearning experience, it is also aget together for people wholove their profession. Manyexperiences are shared, tech-niques exchanged, adapta-tions of equipment and sup-plies shared and perhaps mostrewarding the bonds formedamong window cleaners.

The seminars coveredConstruction Clean Up (CCU),Water Spot Removal andTempered Glass Defects. Theseminar began with CCU infor-mation. This is the first clean-ing that the windows receiveafter the painters, plasterers ordrywall workers have complet-ed the jobs. Dan Fields cov-ered every aspect from wettingthe glass with a window brushto scraping the glass with abroad knife. A broad knife, is a6" putty knife or tape knife(used for dry wall repairs) thatis sharpened on a 12" fine file.The broad knife is not sharp-ened like a razor, but the tip ispushed across the file givingyou a flat surface with 2 sharpedges. If you visitStopScratchedGlass.com youwill read that Fields hasproven that razors or broadknifes do not scratch glass butthat Fabricating Debris leftover from the temperingprocess causes the scratcheson most new windows.

Construction Clean Up canbe very profitable. Manycompanies charge 2 or 3times the regular window-cleaning price. To clean thewindows properly, CCU doestake longer. As I mentionedearlier, here in the UnitedStates, we are dealing with agood bit of Fabricating Debrison the glass. The problem is

wide spread and is due topoor quality tempered glass.Because of this, MWCoA isencouraging everyone doingCCU to get a waiver signedreleasing the window cleanerfrom responsibility for anyscratches on the glass.Below is an example of whatsuch a waiver would looklike.

Jack Nelson

presents Dan

Fields with an

Appreciation

Award for con-

ducting the

seminar to

MWCoA mem-

bers.

PWC MWCoA Seminar : Scratched Glass

From ProClean Window Cleaning Company to Builder:

Tempered Glass Waiver to XYZ Building Co. Releasing Window Cleaner FromAny Liability On Tempered Glass Scratching During Cleaning

Due to widespread problems with poor quality tempered glass scratching during con-struction window cleaning ProClean Window Cleaning will not be liable for any scratch-es on any tempered glass.

It is accepted and understood by ALL parties that properly used razor blades andscrapers are standard tools and techniques for construction window cleaning and cansafely remove limited amounts of construction debris (plaster, paint, texture, tape,stickers, etc) from quality glass, without scratching the glass surface.

Furthermore, it is accepted, the use of razor blades and scrapers will be employed onall construction window cleaning and no other cleaning method will be offered byProClean Window Cleaning to remove construction debris from any glass surface.

If XYZ Building does not choose to have the window cleaner use razor blades or scrap-ers, XYZ Building must cover all glass during the entire construction process, whichwould protect glass from any construction debris and eliminate the need for ProCleanWindow Cleaning to use razor blades or scrapers to clean the glass.

This clause must be included on all contracts. If this clause is not acceptable, there isno contract between ProClean Window Cleaning and XYZ Building Co.

Please initial acceptance of this clause; ________

A typical waiver releasing the window cleaning company from responsibility for any scratch-es on the glass during Construction Clean Up (CCU)



Professional window cleanersuse scrapers and razors on adaily basis without scratchingthe glass. I remember the firsttime I scratched glass. I didn'tunderstand then what hadhappened, but I knew it wasn'tanything that I had done. Ithad to be the glass that wasdefective.

Fields has spent many yearsuncovering the problem.Several window cleanersacross the United States havebeen either sued or threat-ened with litigation. Fields hasgone to bat for many of thesewindow cleaners, and hasnever lost a case as an expertwitness.

We took a break for lunch. Youwould think, we would relaxand enjoy the food that wasprovided for us, but no. Wetalked more about windowcleaning techniques for anhour. Several of the guys sataround and picked Dan's brainfor more information.

The second part of the daycovered Water Spot Removal.This is a very complicatedsubject but Dan’s illustrationsthrough pictures and actualdemonstrations, made it veryunderstandable.

All glass produced in theUnited States is float glass.One side of the glass is calledthe tin surface, the other is theair surface. The tin surface isface down and floats onmolten tin. During the floatprocess 25-30 milligrams of tinmigrates into the surface ofthe float glass.

Types of Glass StainThere are three basic types ofstain on glass; Water Spots,Glass Corrosion and Tin EtchHaze. I will try to explain eachof them.

Water spots are caused byhard water (composed ofmagnesium and calcium) andlook like water droplets on theglass. The water spot is oftenon the exterior of the glass.

This water can be removedeasily with a solution ofPhosphoric acid or vinegar.Another hard water spot iscaused by Silicate. This typeof stain can only be removedby Hydrofluoric acid or polish-ing the spot off the glass usinga polishing system.

Glass corrosion occurs mostlybetween IG units (InsulatedGlass). The corrosion looksmore like bacteria growingbetween the units often turninga shade of white. There is verylittle hope to save the glassonce the seal is broken.

Tin Etch Haze is the last typeof glass stain. Often the tinside is faced inside most IGunits. The exception is if a filmis used such as low-e orpyloric coatings (mirror typefilms). These films need to beplaced on smooth glass. Thesmooth side is the air side. TinEtch Haze will occur when HF(hydrofluoric acid) is used onthe tin side (for the removal ofother stains). To avoid thisproblem, an ultra violet lightcan be used to distinguish thetwo sides. The light will reflectgrey on the tin side and have acrisp cleaner reflection on theair side.

Tempered Glass DefectsThe final seminar of the daydealt with Tempered GlassDefects. This seminar wasfairly simple and easy tounderstand. Glass tempera-tures create the problem ofFabricating Debris by notcleaning the glass properlybefore the tempering process.The window manufacturertempers the glass by heatingthe glass to 1200 degrees F.This process does two things;It causes the glass to become

PWCMWCoA Seminar : Scratched Glass

Each member

who attended

the seminar

received a

certificate


4 to 5 times stronger than annealed glass. Also tem-pered glass breaks into smaller pieces if it shouldshatter.

Here is basically what happens: It all starts with theglass washer and the lack of maintenance to thatwasher. If the glass washer is not properly main-tained, fabricating debris will remain on the glassafter the glass exits the washer. When the glass andany remaining fabricating debris enters the temper-ing furnace, the 1200 degree furnace fuses the fab-ricating debris to the roller side surface of the glassand the furnace rollers. It's this fabricating debristhat causes the scratching on tempered glass.

When a window cleaner removes constructiondebris from the glass surface, they also remove thedefects, which scratch the glass when they aremoved across the glass surface. Also, over time thetempering furnace also becomes contaminated withfabricating debris and must be serviced to removefabricating debris from the surface rollers.

Fabricating debris is difficult to detect and onlyoccurs on tempered glass. Look for the temperstamp on the glass. In the US the glass is labelled intwo different ways. Sand blasted from the furnaceroller side (the side the defects would be on) or aceramic paint stencil is applied to the opposite sideof the furnace rollers (the air side). The sand blast-ed label would be smooth or slightly indented to thetouch. The ceramic stencil would be raised to thetouch. This way you would know what side mighthave fabricating debris.

Fabricating debris can be detected by the followingtest:

A. Wetting the glass with soapy waterB. With a new razor blade (moving only in one direc-tion) make several long strokes across the glassand listen for anything that sounds like there is sandor grit on the surface.

If debris is detected notify the contractor right awayto let him know about your findings.

Although the air travel was miserable for me, buteven a six hour flight complete with screamingbabies, fellow passengers’ smelly feet, boringmovies, no room to stretch and no sleep on my "redeye" trip home were not able to dampen my enthu-siasm. This was an adventure I would not havetraded for the world.

The seminars were professionally video taped andwill be available for sale in the near future. See oursite for details www.mwcoa.com

You can find more information from Dan Fields bygoing to www.StopScratchedGlass.com

PWC MWCoA Seminar : Scratched Glass


Jack Nelson is the executive director of The MasterWindow Cleaners of America. The MWCoA is a tradeassociation formed primarily to represent residential orroute window cleaners. Since it’s foundation it has gainedmore than 100 members, and is going from strength tostrength.

For more information about the MWCoA, see:www.mwcoa.com


MWCoA Seminar : Scratched Glass


PWC

Dan Fields’ Website (www.stopscratchedglass.com) contains much use-ful information on fabricating debris,what causes scratched glass, andmost importantly how to prevent it.


scratched glass - master window cleaners of america · 10 the issue of scratched glass and...

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