Sealant makes chipping worse?

[TANTO]

I'm sure that everything you said is true and accurate. However, let's get out from under the electron microscope and into the real world--a chip is a chip. If my Opti-Coated car gets chipped, it's not because it was Opti-Coated, it's because a rock hit my car. If the chip is 100 microns bigger than if I didn't have Opti-Coat...I still have a chip...it's just an unnoticeable amount bigger...and I still have to touch it up or live with it.

I'm sure if it was a noticeable effect, we'd have a ton of threads complaining about it. At the end of the day the advantages of a coating outweigh the disadvantages--FOR THE PEOPLE WHO WANT TO USE COATINGS.

As I always say, if you want your car to stay perfect, with no rock chips, door dings, etc.; LEAVE IT IN THE GARAGE.

Mr Megane - As a retired engineer i'm thrilled with microscope data and thank you much for your input. Could one find these industry pub's? Setec - I agree with your logic of a chip is a chip, but my read from Mr M is there may be bunches of tiny chips that would not have chipped at all if this hard layer had not shattered above it. Seems logical even without the microscope. Surely you have pulled off paint after leaving tape on too long(?). I think we will find out as Mr M says that this is a well know thing. As far as people complaining, there is no way anyone would know. If i had not sort of remembered that this was an issue years ago, i would have just assumed that the hit was much bigger than i thought. And the sealant may well not have been an issue in my case. It's a discussion. If analytical spitballing is not your thing, just let us BS'rs BS. An old engineering group saying is that "one empirical test is worth 100 expert engineer opinions" so i understand not getting lost in the weeds. I have a door to test on, but reading the industry papers is the short cut to the truth IMO. I will see what i can find.

[PiPUK]

Mr Megane - As a retired engineer i'm thrilled with microscope data and thank you much for your input. Could one find these industry pub's? Setec - I agree with your logic of a chip is a chip, but my read from Mr M is there may be bunches of tiny chips that would not have chipped at all if this hard layer had not shattered above it. Seems logical even without the microscope. Surely you have pulled off paint after leaving tape on too long(?). I think we will find out as Mr M says that this is a well know thing. As far as people complaining, there is no way anyone would know. If i had not sort of remembered that this was an issue years ago, i would have just assumed that the hit was much bigger than i thought. And the sealant may well not have been an issue in my case. It's a discussion. If analytical spitballing is not your thing, just let us BS'rs BS. An old engineering group saying is that "one empirical test is worth 100 expert engineer opinions" so i understand not getting lost in the weeds. I have a door to test on, but reading the industry papers is the short cut to the truth IMO. I will see what i can find.

A google is generally the best first bet but the terms for your search would be 'brittle', 'fracture', 'crosslink density' or similar. As you may well have spotted already on your searching, higher cross linking more or less means increased hardness but excessive level lead to embrittlement. Most of the literature is related to more traditional clear coat and paint technologies but the fundamentals are the same. Take it to extreme and you have to ask yourself why the clearcoats are not made super super hard - often there is plenty of room to increase crosslink density. As you say, this is a thought experiment and all I am saying is that hardness alone is not enough.

Now you should not interpret my words as 'coatings are bad'. If the product is done correctly, my words may very well not apply. BUT I have heard enough discussions about supergard or gard-x and stone chips to make me wonder.

[RaskyR1]

I'm not buying that a sealant, wax, or even a coating is going to have any effect on stone chipping being worse or better, but if someone wants to shoot Dr. G an email I'm sure he can answer this question for you.


FWIW, My Acura chipped just as much with and with out Opti-Guard.

[Blackthorn One]

I find it difficult to believe that a hard coating on paint can increase the incidence of chipping. It seems to me that a harder coating on a softer base is like case hardening on metal to make the surface harder, without hardening the metal throughout, so that the entire part does not become too brittle.

A well made sword, like a Samurai sword, is hard on the outside so that it can hold an edge, yet is springy on the inside so that the blade can flex instead of breaking.
Part of how the best swords can do this so well is because of layering harder metals around softer ones.

I have heard however, that sealants that contain silicone can make touching up paint more problematic, because the silicones are absorbed into the paint, causing new paint not to not stick properly. That was the big concern in the 80's when sealants first started becoming popular.

[PiPUK]

It is hard to give realistic macroscopic analogies... that is the thing with the microscopic and nanoscopic world - the behaviour is often not as one would expect from macroscopic world experience.

The best one I can think of on the bonding on the surface is superglue on your fingers. What happens when you rip your fingers apart? You rip the skin off at the same time. I realise that this is a totally different scenario but fundamentally you are applying a force larger than the shear strength of the system and you are causing a whole load of damage to the underlying area. Had you been using PVA glue, the glue (or top coating by analogy) would have been ripped apart whilst the underlying would have been OK.

For background, I am a chemical manufacturer, I formulate new products like most people eat snacks, my initial education and doctoral studies were in atomic and molecular physics and I have also studied and published for a time in silicon and semiconductor surface modification. Not to say I cannot get it wrong... but if you are interested in learning, don't dismiss my thoughts without taking the time to reason through and do a bit of reading on the topic.

I'll shut up now!

[ihaveacamaro]

It is hard to give realistic macroscopic analogies... that is the thing with the microscopic and nanoscopic world - the behaviour is often not as one would expect from macroscopic world experience.

The best one I can think of on the bonding on the surface is superglue on your fingers. What happens when you rip your fingers apart? You rip the skin off at the same time. I realise that this is a totally different scenario but fundamentally you are applying a force larger than the shear strength of the system and you are causing a whole load of damage to the underlying area. Had you been using PVA glue, the glue (or top coating by analogy) would have been ripped apart whilst the underlying would have been OK.

For background, I am a chemical manufacturer, I formulate new products like most people eat snacks, my initial education and doctoral studies were in atomic and molecular physics and I have also studied and published for a time in silicon and semiconductor surface modification. Not to say I cannot get it wrong... but if you are interested in learning, don't dismiss my thoughts without taking the time to reason through and do a bit of reading on the topic.

I'll shut up now!

Please don't. I love reading your posts! Having someone disagree with you makes it even better because I get to read more opinions and your responses to them.

Now, I'm not saying you're right or wrong. I'm just saying don't stop responding, because your posts (regardless of accuracy) have insightful and well-spoken arguments.