One of my older repairs

[OmNi]

I checked up on one of my older repairs and noticed that a little bit of the pit had come out. No yellowish coloring nor did the whole pit fall out like many of us see on a regular basis. Perhas I didn't let it cure long enough??? The repair was done in 20ish degree weather. The repair I'm sure was done in temp around 60-70 but the curing process may have been much lower.

The customer didn't even notice the weakened chip, but I did patch the damaged area and made it happy again

-Jason

[Brent Deines]

How old was the chip?

It is an acrylic, so it will wear quicker than glass, so over time the weather, road debris, and wipers will scratch and even chip the resin in some cases. If a rock hits the same spot it can chip out some of the hardened resin even if it did not hit hard enough to chip the glass.

[GlassStarz]

I know in places like vermont where it gets to 30 below in the winter and 100 deg in the summer I have seen several pits fail (mine and others) the drastic swelling and shrinking and massive temp differences add to the fail rate generally I clean the pit and add pit filler and move on

[Brent Deines]

I worked in the same kind of temperatures in Montana. Can't say I've ever seen my pit fail, but the surface does show wear over time. I have seen pits that others have done fall completely out, but I always attributed that to poor resin quality as the bond between a good resin and the glass is very strong.

Rain-X and other coatings can weaken the bond if the surface is not properly prepared.

[Sneck]

Of all the failed pits that I have ever seen, there seems to be one common thing about them all, and that is that they were all drilled. You can tell quite easily by noticing how perfectly "round" the missing pit was, and the fact that it was the exact same size of a drill bit. Some had turned yellow like bee-poop, while others just came clean out. I notice the missing pits more on vertical glass, but have also seen this on car windshields as well. I have not noticed it on any my old repairs, I never drill unless it is absolutely necessary.

I think these old failed pits are happening due to extreme temperature changes too, but I also think the smooth walls of the drill hole aid in the old pit filler to slip out.

Sneck

[splitpit]

I'd have to disagree on the corilation between drill holes and pit failure. A good quality wsr resin and good quality pit resin should interlock together forming a strong chemical bond with each other and with the glass.
I'm not an advocate for drilling, but that should have no bearing on whether or not the pit resin stays in place, unless the drill hole had an air pocket in it and was not completely filled.

[OmNi]

Thanks guys.