Scratching My Crack

No big explorations to report on either Wednesday or Thursday. We just hung around the RV park working on more of those catch-up things that have been hanging over our heads, as well as a run to the local Cabelas store.

Bus-house windshield. The bus-house is four and a half years old and has 36,000 miles on the odometer. We still have the original windshield, but it has taken a beating during that time. It's a huge hunk of glass (5' tall by 8.5' wide)... one of those one-piece jobs that some years ago motorhome manufacturers started installing for the "un-interrupted panoramic view" out the front end. I guess that's supposed to be a "feature".

The downside to this whole "one-piece" idea comes when you have to replace the dang thing... it's a major job. With the old split windshield, replacement is a relatively easy task. I've watched the replacement of a half windshield in an RV park some time ago. Two guys from the auto glass service can remove the old and install the new in a matter of 20 minutes or so. It's a reasonably sized piece of glass that two guys can handle without special equipment.

But replacement of these huge one-piece buggers is a major job. First off, they're not going to come to you in the RV park and replace it in 20 minutes. No sir (or madam), you'll have to break camp and drive over to their place. Second, not many shops keep something like this in stock and it'll have to be ordered and shipped. And thirdly, the windshield is so big and heavy it takes a crew of people and a fork truck to do the job. Additionally, as these things often go, there's the good chance that something won't be done right, it'll leak somewhere or something, and you'll have to make more trips back to the shop for "get-it-right" follow ups.

And a big downside for me is that after you've gone through all the hassle of getting it replaced... and you've got that big new shiny hunk of glass up front... there's the overpowering fear that it'll get nailed again by a passing gravel truck within the first few miles. So, for me, having a windshield with a few repaired chips and impact craters is better than a new one.

Our windshield has sustained 5 impacts large enough to cause damage over it's four and a half year life. It's interesting to note that I remember the exact spot on the map where each one occurred. The largest divot, one so big the chip repair guy would only do it because I insisted, happened in Montana, on two-lane US-191 between Hilger and Roy about three and a half years ago, when a car traveling the opposite direction kicked up a stone -- a boulder really -- that sounded like a gun-shot when it hit.

a little larger than a quarter.
(color and contrast altered to enhance image)

 Of the first four impacts, two were repaired professionally and two were small enough I took a chance and just let them go. None of the four caused a running crack to develop.

But the fifth one... just a couple weeks ago, was a relatively small hit. I heard it, but could see nothing immediately afterward while driving and thought we lucked out again. However, when we stopped for a break and I took a look from the outside... there was a small chip right on the lower edge on the drivers side... and, curses, there was already a crack, two or three inches long, running northward. Dang! Common knowledge says that once a crack develops, it'll continue to run until it's big and ugly and crosses directly through the driver's line of sight. Replacement is inevitable. Since it happened it has already grown to about 6 inches.

Hmmm. A thought was rolling around in my head. If I could drill a hole at the end of the crack... could that stop it? A little online research indicated that might work... but drilling the hole is problematic because you need a diamond drill bit and steady hand... and there's still a big chance that the whole dang windshield will shatter.

But then I found buried in a user forum somewhere... a comment from an ex-stock car racer that said he had stopped windshield cracks from spreading by taking a simple glass cutter (less than 5 bucks at any hardware store) and scribe a half-inch score in the glass at the furthest point the crack has progressed. The score should be perpendicular to the direction of the running crack. He says he's never had one continue to spread afterward.

There's only one crack... the lower one is a reflected image.
Note score across path of crack.

So, this morning I did exactly that... I scratched my crack.  And we should know pretty quick whether this simple idea works. It may look a little ugly, but if it stops the crack from spreading it will save this chunk of glass for a little while longer. I mean, I've grown very attached to this old scarred windshield.

UPDATE September 2:  The idea that you can score the glass ahead of the crack to stop it from spreading has failed. I don't know if I didn't do it right or if my stock car driver source was just making it all up... just don't know. During our recent "big headwind" day, we watched the crack spread despite numerous attempts to score it in this manner.