How does clear coat adhere?

[Garrett1984]

Hello all. Can someone please tell me how clear coat is able to stick to basecoat? Obviously a painter shall not sand a base coat before applying clear coat. It is also understood a painter could apply a clear coat over a base coat that has sat many days after application. So, if there is no mechanical “tooth” or chemical adhesion happening between a base coat and clear coat…how does clear coat keep from flaking off?

 

[dhutton01]

From google

Clear coat sticks to base coat through a combination of chemical bonding(isocyanates) and solvent action, where the clear coat's solvents slightly reactivate and melt into the base coat during its "flash time," creating a strong, smooth, glossy finish that protects the color.

 

[Garrett1984]

Thank you for your explanation.

 

[AAE]

From google

Clear coat sticks to base coat through a combination of chemical bonding(isocyanates) and solvent action, where the clear coat's solvents slightly reactivate and melt into the base coat during its "flash time," creating a strong, smooth, glossy finish that protects the color.

Pretty good for a"backyard hack"!

 

[OJ86]

 

[Big Dave]

From google

Clear coat sticks to base coat through a combination of chemical bonding(isocyanates) and solvent action, where the clear coat's solvents slightly reactivate and melt into the base coat during its "flash time," creating a strong, smooth, glossy finish that protects the color.

I thought it was just, “sticky”

 

[metalman]

So, if there is no mechanical “tooth” or chemical adhesion happening between a base coat and clear coat…how does clear coat keep from flaking off?

Sometimes it does flake off, courtesy of the OEM.
But seriously it does that because the factory tries to get away with as little as possible clear applied. What the factory uses and what the refinish network uses are different products. At least according to my CRS memory.

 

[metalman]

View attachment 39181

At my shop I use "smoke and mirrors".

 

[Treeslayer]

Sometimes it does flake off, courtesy of the OEM.
But seriously it does that because the factory tries to get away with as little as possible clear applied. What the factory uses and what the refinish network uses are different products. At least according to my CRS memory.

i was about to ask that. i am certain what they used in the 90s-2000s was not what we have today. being a dodge guy, just about every thing fromt hat era thats come my way had no clear or very little left.