I so wish I had listened to that advice earlier. As it is, I no longer use a blade on glass. At least not very often. What kills me is how few builders know or care why their glass is getting scratched....until THEY have to replace it...
That's the problem so many window cleaners are running into. A good waiver, while not being a substitute for insurance, will protect you from liability from defective tempered glass. If a builder or homeowner will not sign a waiver, I won't use a scraper, and probably won't even do the job. The International Window Cleaners Association has great information on Fabricating Debris(even a sample waiver), as well as the newly formed Association of United Window Cleaners. Gary Mauer and Dan Fields, tempered glass experts and window cleaners, both have websites; scratched-glass.net and stopscratchedglass.com. They have kept many window cleaners out of hot water, including me.
Scraping ANY glass must be done properly.
-Clean the glass first.
-Then get the glass good and soapy. This provides lubrication.
-Use a sharp, new blade. Triumph scrapers and blades are all I use.
A sharp blade WILL NOT scratch glass. The dirt/debris you push with the blade WILL. Keep the blade clean and don't scrape concrete/welding spatter. If you do hit something like concrete spatter, your blade is ruined. I will use a blade on low-e glass but only when the above conditions can be met. I have never scratched a pane of glass.
I would have to say the most important thing that i have foung is to make sure that the glass is wet when scraping. This is HUGE!!!!! and never use and abrasive sponge i found that out real real quick (but fortunately it was my house)
You're right about the procedures to clean glass with a scraper. However, it doesn't matter how clean a blade is, how often you change it, or how often you clean it, if fabricating debris is present, it WILL scratch the glass. There are only limited ways to detect defective glass, and they are described on the websites that were posted earlier. Defective glass is almost always found once it is too late. That's what makes it so important to educate the builders and have a waiver signed.
I find that it takes at least 3 cleanings to make the windows perfect. Excessive scraping is really the culprit here. I make sure that the contractor knows this before and then let them make the decision. Silicon over time will harden on the outside and it will come off in layers. And I believe that silicon is where most overscraping occurs. How many of us have just spread it around? Building contractors generally don't care because the aura of a new buildings takes focus off that kind of stuff, the building owner finds this out later.
I agree. You can't wash the windows once and expect them to look perfect. I sometimes liken it to going to an adult going to the dentist the first time in his life. It will take many visits to have his teeth in perfect condition. On the other hand, if a builder requires that the windows be in spotless condition, I simply keep washing back to back till they're clean. There are several cleaners that work decently with removing silicon. A "tip" I've heard is talcum powder, although I have yet to try it, and not sure if it works or not. Supposedly, the talcum powder is attracted to the silicon more so then silicon is attracted to glass. Fine grade #0000 steel wool is another tool used to remove silicon, as well as other substances on glass.
On non hardened glass and with the right chemicals, I can scapre a pane once and it is clean. Of course, I will then need to strip and squeegee.
I am not sure what excessive scraping is...no offense meant. If a pane has NO fab debris, I can run a blade across it a thousand times...no prob.
I am also learning that builders do care, they just do not know what to do but replace scratched glass. At least not many. I am the only one in my area that has done the research...and by that I mean i am standing on the shoulders of those before me. Peopl ehave a tendency to do waht they have done before...unti given a reason to change.
If a window cleaner knows how to clean new construction glass, he or she is very valuable to builders. The hard part is letting the builder know you are there...not finding one who cares. Granted, not as many care now as will say after they spend another fifteen or twenty thou in replacement.
I have given in to educating my home owners wht their glass has scratches...and they are pissed. some have picked up the phone and called the builder...NOW that builder cares.
Micah, you mention talcum powder. There's a product called Restoro that's designed for scrubbing without abrading. I'll use it to remove hard water stains and the fog left on windows due to metal screens. It's spendy but a little goes a LONG way. And yes, I agree about fab debris, but like I said, it's not the blade scratching, it's the debris you push across the glass.
Often, I will follow a glazer who has put a dozen or so finger prints in the glass during the install. Of course, on his finger was silicon. I tired a bazillion things to remove but my favorite is 0000 wool and no water. The trick is rubing lightly. The reason I use no water is, when the silicon prints are wet, they tend to vanish. Once they dry "ta da" they return. I also use wool for smudges and smears I left during the clean. Once everything is dry, wool works great for detail.
excessive scraping is when you have to go over a spot more then 2 or 3 times. My reasearch was done with experiance. Doing all my work in the new york metropolitan area, i have done over 100 new commercial buildings. Having tried all types of stuff from steel wool to soft scrub, stainless steel truimph scraping blades work the best. Unfortutnaly they are expensive and they wear out quickly. Scraping sucks but its part of the job and if you are good at it then damage is always limited to nearly none.
A person who has never touched a scraper can scrape a quality plate of glass that is wet all day and never scratch it. In contrast, a skilled window washer can run his triumph over a plate of defective glass and not knowingly scratch it due to fabricating debris in a single pass. Pepsieddie, you stated that :
"Scraping sucks but its part of the job and if you are good at it then damage is always limited to nearly none."
Does that mean that if you are 'good at it' that you can't scratch a plate of glass with fabricating debris using a scraper? You mentioned you have done over 100 CCU's on the glass for commercial buildings. Do you have waivers signed? Do you know how to spot fabricating debris?
I too am fond of the triumph ss blade. i also use a broad knife..that ads life to the triumph blades.
I can scrape all day myself no prob until I hit fab debris. I am not good enough yet to scrape glass with fab debris.
I am sure willing to learn that skill. if, any one teaches it.
in over 20 years of window cleaning you are the first person i have ever heard use the term fabricating debris. Micah have you ever bid on a job in the ny area? Try to go to a builder or contractor or maintenace company and tell them you will only take the job if you you do not have to be responsible if you damage the window. You can wave goodbye to the job. Regardless of the debris someone is going to take the job and the person paying only wants to know when it is done. I personally give the the gc the info and let them make the decision. I guess the answer to your question is no I can not spot fabricating debris. I have yet to lose one penny because of scratched glass although i probably am jinxing myself. Real experienced professional window cleaners almost never damage glass regardless of the circumstances, but I suppose it can happen. My advice to anyone worried about damaging comercial glass is stick to store fronts they are much safer.
Fabrication debris is a huge issue cross country. You are very lucky if you dont have to deal with it. It could be that the glass manufacturer (s) only send the good stuff to your area. But dont be fooled into thinking you are not scratching glass as a result of your talent. No offense meant....if you have never heard that phrase before then you must not be around the industry other than your work. The phrase was created some years back by Dan Fields, the leader in the industry for specializing in scratched glass restoration and prevention.
If you ever relocate, be sure to learn more about the subject for your own protection. It does exisit, it does cost serious money and in my area, YOU will be blamed for it unless you educate the builders.
Hope this does not read like an attack. I truly mean no disrespect.