Clear Coat

[Don Porter]

Had a fellow ask me"if a clear coat is clear, why does it show up white when scratched". I told him I wasn't sure, but may be do to pigmentation. Anyone have the real reason?

[LazyGhost]

The clearcoat is clear, and the paint beneath is not. Scratch a clear surface and it is no longer clear. And the paint beneath makes it more visible and stand out.

Just my uneducated opinion.

[AutowerxDetailing]

This is why:

(I tried to insert a #### link but it is broken for some reason... I will paraphrase instead)

When paint is polished to a high level of perfection the light bouncing off the paint and into your eyes is the result of specular reflection (a mirror like reflection of light). When a surface is rough (like when a scratch interrupts the perfection of highly polished paint) the light is scattered, resulting in diffuse reflection. This causes light to be scattered away from your eye and in random directions. Most objects that we see are the result of diffuse reflection.

When clear coat paint is polished to a high level of perfection you essentially cannot see the clear coat, rather, you see through the clear layer. When it is scratched or imperfect the optical clarity is distorted causing diffuse reflection allowing you to see the clear coat; or, more specifically to see the imperfections in the clear layer.

[FUNX650]

This is why:

(I tried to insert a #### link but it is broken for some reason... I will paraphrase instead)

When paint is polished to a high level of perfection the light bouncing off the paint and into your eyes is the result of specular reflection (a mirror like reflection of light). When a surface is rough (like when a scratch interrupts the perfection of highly polished paint) the light is scattered, resulting in diffuse reflection. This causes light to be scattered away from your eye and in random directions. Most objects that we see are the result of diffuse reflection.
When clear coat paint is polished to a high level of perfection you essentially cannot see the clear coat, rather, you see through the clear layer. When it is scratched or imperfect the optical clarity is distorted causing diffuse reflection allowing you to see the clear coat; or, more specifically to see the imperfections in the clear layer.

I'll go one step further...Using your paradigm:
"Most objects that we see are the result of diffuse reflection"...


-Clear Coat (paint) is another type of a 'plastic' (urethane, polyurethane...for example).

-Clear Coat, then, which like most plastics, is also susceptible to...And will haze or turn a:
'Certain-Color' when it's resin-base is "disturbed".

-Diffuse reflection, in turn, is one of the means that allows the human eye to "see"
the above 'Certain-Color' as being one of the: WHITES...as it were.




Bob

[Mike Phillips]

When you abrade a clear surface the abrasion is opaque. Look at scratched or scuffed glass as an example.

When you sand a clear coat it turns opaque. When you remove your sanding marks you remove the opaquness and restore clarity.

[Don Porter]

Thanks Mike. That's the answer I was waiting on.

[FUNX650]

Thanks Mike. That's the answer I was waiting on.

-So...Then...The 'color' of opaque is: White?

-Is that what you're going to tell the fellow in your OP, listed below?

Had a fellow ask me"if a clear coat is clear, why does it show up white when scratched".
I told him I wasn't sure, but may be do to pigmentation.
Anyone have the real reason?

Bob