Johnson Window Films Dealer Resource Center

JWF, Don't Scratch Glass

Don't Scratch Glass

Fortunately, scratching the glass is a rare occurrence but if you are careless, it can happen quickly. Pay attention to a few general rules, you should be in good shape.

Keep the tip sharp.
Break off dull blade
tips often
• Make sure to start with a new stainless steel blade before cutting your pattern.

• Secure the cap onto the box in which you store the blade.
This procedure keeps the oil on blades from evaporating.

• When cutting your pattern, make sure to poke the knife through the film and angle the blade 45 degrees as you glide the knife across the glass. Try not to apply too much pressure.

• Always clip off the old blade and start with a sharp new blade each time you take the knife off the glass.

• Many professionals place a button between the film and the window when cutting the film. This technique prevents the blade from touching the glass.

• Use extreme caution when working with new tempered glass.

Try your best not to scratch glass.
Cutting security film

Working with security film
Because security film is thicker, the chances of scratching the edge of the glass during the cutting process increases. It's easy
to accidentally scratch the glass surface when using a large heavy-duty knife and pushing hard to cut through 7, 11 or 12 mil. security film. This error weakens the glass and defeats the intended effect of security film.

Our recommendation to dealers who install thick security film is to cover the edges of the window with masking tape before trimming the piece to fit. After applying the masking tape, trim the film on the glass as normal then either roll the film up or hang it on another piece of glass. Remove the masking tape and make a final cleaning to the window before installation. This technique not only helps eliminate possible scratches, but it actually makes the installation process go faster.

Please keep in mind these helpful tips are not a 100% guarantee that you will never scratch the glass. Unfortunately, film installation is prone to human error from time to time. But if you take steps to minimize potential installation problems, the chances of delivering a successful installation greatly increase.

Extreme Caution – New Tempered Glass
(aka Heat Strengthened or Toughened Glass)

Note: Do not clean with a razor blade scraper.

In recent years there has been a dramatic increase in the use of “poor” quality Tempered Glass. The glass surface can be easily scratched when standard window cleaning techniques are employed, ie; Razor blade scraping.

Poor quality Tempered Glass can be identified by its blemished surface, usually, but not always, found on the side of the glass with the identifying safety engraving. This blemished surface consists of points on the surface of the glass not visible to the casual eye but create a gritty sound when scraped off the surface. During the scraping process these points are dragged across the surface of the glass causing numerous fine scratches.

Therefore the cleaning of new Tempered glass requires special care. A cleaning method which does not dislodge these points or particles needs to be employed. A soft cloth and plenty of soap solution should be used in a small circular motion and then wiped clean with a soft rubber squeegee. Repeat these steps until the glass is satisfactorily cleaned.

If the glass is extremely dirty – you can test scrub a small section of the glass with a non-scratch scourer pad. Our (TT-181) can sometimes be used successfully, but we recommend that you continually stop and check your work.

Please feel free to contact us for further guidance and information.

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