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Commercial Glass Plate Repair Info
Office and Store plate glass, differs from windshield glass in color, (clearer) in thickness, (much thicker) and cost, (very much more).
In fact, a sheet of plate glass could cost 30 times or more the cost of the most expensive windshield.
And the loss of business while a ten square foot window is replaced could cost even more than the glass.
Both of which are powerful reasons for an owner to want his plate glass to be repaired, not replaced.
There is one very important difference between repairing a windshield and repairing a large slab of plate glass.
A crack in a windshield is safe and easy to repair.
A crack in a ten foot square piece of plate glass could start a structural failure of the glass.
A structural failure in a ten foot square. 600-pound slab of glass could cause it to fall out of its frame, injuring or killing anyone under it.
So, other than small edge cracks due to mounting stress, there are almost no cracks in plate glass that are safe to repair.
However, many rock or bullet-caused impact holes in plate glass, that are not part of a crack, can be repaired by filling with Liquiglas PG resin.
Impact of a bullet or a rock on plate glass usually punches a hole that will have clean edges at entry and exit.
However some entry or exit hole edges in plate glass may have many small radial cracks.
Some of the radial cracks may be visible, even after the hole is filled with resin and cured.
If the plate glass is very valuable, there are glass tools that grind away radial cracks, enlarging the hole, but that work is probably best left to glass installation people.
Plate glass impact-hole filling is simple and quick.
The impact hole is blocked on both sides with Polyblock squares, protected from resin by sheets of Optifilm.
The Polyblock squares are held in place over entry and exit holes by two 10-inch long, two-suction-cup, plate glass Optibridges.
There should be just enough space between top of the hole in the glass and one of the Polyblocks to allow Liquiglas PG resin to be squeezed into the hole directly from the bottle.
Pressure of the center screw of the plate glass repair bridge holding the Polyblock on the window should be enough to hold it in place on the window, without causing the Polyblock to bend inwards.
If the Polyblock is bent inwards by too much pressure of the retaining screw, the repaired hole after resin cure would have a dished-in surface.
Most Plate glass damage is in stores on the ground floor, so access to the damage is simple.
Occasionally however an impact hole in a plate glass window on an upper floor may need to be repaired.
If the outside of an upper floor window cannot safely be reached, a window cleaner may sometimes be persuaded to cover the hole on the outside of the window with a strip of scotch tape, while you cover the inside hole with an Optibridge.
The scotch tape will need not be removed, since it will, in a matter of a few days in the sun, dry out and fall off the window.
Ultra-violet lamp or sunlight cure of up to a half inch of resin in the impact hole will be slow.
A complete cure may take 15-30 minutes, after which the repair bridges may be removed and resin edges trimmed with a razor blade.
Occasionally the surface of the cured plug of resin in the hole may be rippled or rough.
This roughness may be polished away by an Optikleer glass scratch removal buffer using common white toothpaste as the abrasive.
Before the cured PG resin in the impact hole is polished by the Optikleer bufer, the hard felt buffing head must be washed carefully to remove any traces of coarse glass polishing abrasive that may be left from previous glass polishing.
Any coarse glass polishing abrasive left on the pad will be sure to leave sratches on the surface of the cured PG resin in the hole that will be difficult to remove.
In dry weather, if cured resin tends to stick to the Optifilm sheet covering the Polyblock, the Optifilm before being installed, can be sprayed lightly with mold-release that can be found in almost any hardware or craft store.
If no mold-release is available, Pam no-stick cooking spray, from the nearest grocery store is a reasonable substitute.
Plate glass repair is slow and an impact hole may take from an eighth of an ounce to an ounce of resin, so your minimum charge for a simple repair should be at least $100.
Not very much money,when you consider that you may be salvaging a $5000 window.
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