[QUOTE]Originally posted by SCS2k
[B]Jeff and All,

The ONLY chemicals to contact my lenses were applied by the Ston Gard installer.

 

No offense, maybe you never stepped on a tin can before (i.e. compression)? I do failure analysis on a daily basis and your statement is pure and simply; false.

[QUOTE]Originally posted by babylou
[B][QUOTE]Originally posted by Sunchild
[b][QUOTE]Originally posted by babylou
[B]First you say that the elasticity of the Stongard won't impede the flex in the lamp plastic, but then you say that stretched Stongard will compress the lamp plastic.

 

As for shot peening....it accomplishes two things; material compression (i.e. strength) and stress relief.

 

Utah, you lost me!

What do you think made both those lamps get cracks?
What are the posibilities?

Barry

 

doc,
do oncoming cars still flash their brights at you with these screwed up lens covers???????

 

Jeff,

Please read more carefully. The car has NEVER been professionally detailed. I do ALL of the cleaning myself and have done so since the car was new. To state this another way: The only time a chemical other than soap or H2O has come into contact with the headlight lenses of this car is during the application and after the removal of the Ston Gard. Both times the chemical (window cleaner) was supplied and applied by the Ston Gard rep. The lights were NOT cracked at the time of application. This leaves only two possibilities as to how these lights have become cracked.

1) The lights were intrinsically defective. Doubtful as they went for nearly a year with no problems in over 110 degree heat.

2) The Ston Gard product or its application caused it. The application was performed by a Ston Gard rep therefore who else could possibly be responsible other than the Ston Gard company?

 

I try not to drive the car after dark as the cracks tend to scatter the light from the headlights.

 

Bob, I think Sunchild's talking along the lines of Pre-Stressed Concrete and the such.
The stretched plastic is exerting only compressive forces (in all directions) in the plane perpendicular to the cracks. No buckling mechanism (i.e. Tin Can) for failure either with the convex shape lens with a meaningful thickness, I wouldn

 

Yes, just to clarify: my question was whether removal of the stongard plastic from the lamp plastic could possibly "relieve" the lamp plastic in such a way that it would suddenly "decompress" at a rate that could cause cracking. Someone else said that the stongard plastic places the lamp plastic under constant compression, presumably because it adds resistance to the lamp plastic's normal expansions/contractions.

My god, I have no idea what I'm talking about. I think it was the damn glass cleaner anyways, because I thought the lamps were glass until this whole thing happened. Shows what I know.

 

There is no evidence to give either side 100% of the blame, but you can't be suggesting that the customer in the middle takes the blame instead. There is really nothing to "wait" for. Whether there is enough evidence or not, Stonegard is responsible for those lenses. I'm not a scientist, but I AM a consumer, just like you and our friend at stonegard himself. If this happens to me, or you, Greg, we are certainly not going to "wait" for someone to claim responsibilities to those lenses. This isn't an expensive car, but you don't exactly drive around a 35k car with cracked lenses. If Stonegard is so sure that someone else is at fault, replace the lights, refund the stonegard and nicely ask the customer to use other products. It's the cost of doing business. It's very simple.


[QUOTE]Originally posted by gregstevens
[B]Insider information and good sources tell me that this will be over shortly.