Ask The Doctor
pros who know
If It Doesn’t Fill, Drill
by Richard Campfield
I believe drilling is a nec-essary skill for a professional windshield
repair technician; it is not optional. I do not know of any legitimate
windshield repair manufacturer that does not sell and teach drilling.
However, some retail operations have eliminated this fundamental procedure
in recent months, creating a large need for re-repairs.
The better you are at drilling and tapping a bullseye, the better a technician
you are. The drill is a windshield repair technician’s best friend and
will bail you out of anything that can go wrong during a repair. When
it comes to speed, why would you want to spend 10 to 15 minutes to maybe
fill a break when you can completely fill it in less than 60 seconds by
drilling and tapping a bullseye? In windshield repair the rule of thumb
should be “if it doesn’t fill, drill.”
How to Drill
Rest the palm of your hand on the glass, and hold the drill like a pencil
and drill halfway through the outer-lite with a 170-172 bit (1/36 of an
inch). Some folks like to steady the drill with the other hand, too.
Only a few seconds of drilling may be required, as the impact point may
be close to halfway through already. Once you’ve drilled the break, place
a needle in the hole and tap a mini bullseye. The goal is make access
to every part and crack in the break through the tapped bullseye.
This is the reason most do-it-yourself kits don’t work—most breaks require
drilling to allow access into the cavity when there is no round bullseye
under the impact point. This includes the two most common windshield breaks,
the radiating crack and the partial bullseye.
Most direct windshield repair marketers will tell you these two breaks
make up more than half their repairs. Those who do not do direct marketing
will see these breaks usually as the second or third breaks as many consumers
do not think these small breaks are serious enough to take the time to
get them repaired.
Glass breaks on the opposite side of impact. The break or cavity is on
the backside of the outer-lite against the PVB interlayer.
Filling a cavity in dentistry is comparable to completing a windshield
chip repair. The dentist drills a small hole from the top of the tooth
into the cavity to fill it with a methacrylic to save the tooth, while
a windshield repair technician drills a small hole from the top of the
glass to fill the cavity with a methacrylic to save the windshield. In
both cases, the tooth and the windshield already are damaged.
Many of us have been re-repairing disgraceful repairs for decades and
we have become very good at it. All it takes is the required skill of
drilling to gain access and re-repair those breaks into which no resin
has been placed. You must drill into the void and fill it with a resin
that bonds to glass and acrylic.
Richard Campfield is the founder and president of Ultra Bond Inc.
in Grand Junction, Colo.
© Copyright 2011 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.