Do any of you use a razor to scrape entire surface of window?

Guys, today i tried using a razor to scrape the entire glass. Although it cleaned all the junk off, i did notice it put some scratch marks going the distance from the top to bottom. Do you all scrape windows with razors and if so, how much pressure are you to apply to scrape?

you may want to do some research on fabrication debris.

Yes and no. Very little pressure. It all depends on how dirty the glass is. Very dirty - gets scraped fully. The less dirty - the less I scrape. A scrape here or there for new glass unless it has a coating, then I scrape the coating off too. Learning and knowing about fabrication debris helps too.

Really? Your methods baffle me.

What this guy said is smart, and would be worth your time. He may look like a clown, but he knows what he’s talking about. Use the search feature for “fabricating debris.”

For the most part we really are all here to help. The last thing we want to see is someone falling victim to poor quality glass just trying to make a living. Educate yourself.

I also highly encourage learning about fabricating debris.
To jump ahead, though, here is some advice on when you [I]do[/I] scrape:
You’ll end up saving time by just thoroughly wetting the whole window and scraping every square inch of it. Do it methodically so that you’re thorough. When you squeegee off a window and see a handful of spots needing scraping afterward, you’ll end up spending more time and wondering if you missed some spots.

… Yes, educate yourself. Then you will have no fear about scraping and you won’t be reckless either.
Oh, and don’t forget that scratched glass waiver!

Something I learned while helping a film installer(not factual but makes some sense from their prospective) Many seem to heavily soap the glass and slowly razor the glass from the top down with the razor at a very steep pitch. Theory behind it is if and when the razor dislodges the fd, it gets caught up in the solution and unable to cause more than usual damage unnoticed by the film.
I still can’t bring myself to do it.

This is where we differ.

Why no waiver?

Using razors should really be a last effort if nothing else works out, such as pre treating and scrubbing with a white pad.

Razor usage is generally used incorrectly, and fabrication debris can make the issue worse when it comes to scratches.

A waiver, seems to be used to get yourself out of trouble. But really you should know what you are doing, and how fabrication debris affects razor usage first.

This education should then be passed onto customers, prior to a waiver being requested.

I totally agree and if a razor is used, I try to be as light as possible. The one razor I bought, it is I believe a 6" and it seems too wide because the entire blade does not fit flat on window

What are you cleaning, 5 inch panes? But anyways I have a Several 6"s and 4"s.

no doing pretty large ones and it only contacts small patches of glass

about 99% of the time it comes down to this:

  1. there is no FD and you can scrape as hard as you want in whatever way you want with no worries. tempered glass is really hard to scratch if it’s not defective.
  2. there [B]is[/B] FD present, so if you scrape at all it should only be a small blade and very gently to remove individual spots. it should be a last resort.

learn how to identify FD and you wont have any problems. it’s the first thing i teach my new guys, even before they pick up a squeegee (seriously). i don’t bother with waivers because we don’t scratch glass.

i scrape the crap out of really dirty windows if it’s good glass. dan wagner is right. if it’s dirty enough you’re better off scraping it first vs. scrubbing like a monkey for five minutes and still seeing gunk after you squeegee.

How do you identify FD? Do you carry a microscope on the truck?

To elaborate a little, if a window is super dirty [I]AND NOT TEMPERED OR HEAT-TREATED,[/I] I’ll usually mop and squeegee it first to get all the loose dirt and unknowns off. Then if there is stubborn stuff still on the glass I’ll do as I posted earlier. Even on annealed glass, there may be some foreign matter, not part of the glass itself, that will scratch the glass when you push or pull your scraper.

  1. run your scraper over lightly over about 1" of the wetted glass surface (dont’ worry, this method won’t scratch the glass). FD makes a distinctly gritty sound, like it’s covered with fine sand.

  2. Look at how your solution rests on the glass. if it’s an even coat that’s consistent across the surface of the glass, you’re probably good. If it seems to “scatter” that’s a tell-tale sign of FD.

combining these two indications will give you a pretty clear indication of wether FD is present or not.

there’s a short learning curve to using these two methods in conjunction (i can teach my guys to identify FD in about 2 minutes), but once you have it down it becomes a simple diagnosis. takes about 2 seconds and is about 95% effective.

for the remaining 5% of glass where you just can’t quite tell- don’t risk it. “if in doubt don’t get the scraper out”…

hey, that’s pretty good… i’ll have to trademark it.

Great advice! Today on a job, I used a scraper and did hear what appeared to be sand on my window. However, I was scraping because I was seeing myrids of small paint so maybe not