PDA

View Full Version : Im trying to understand clearcoat



McCoy
06-16-2015, 11:04 AM
I read in a thread yesterday where somebody was buffing a black car (maybe it was the Porche thread?) and their pad was turning black? What causes this?
I thought cars were covered with clearcoat......so why would the basecoat paint be coming off?

Mantilgh
06-16-2015, 11:13 AM
It may have been a single stage paint, meaning it had no clear coat. Unless it just had a lot of imbedded contaminates, but typically these are mostly removed before the compounding/polishing step.

McCoy
06-16-2015, 12:12 PM
It may have been a single stage paint, meaning it had no clear coat. Unless it just had a lot of imbedded contaminates, but typically these are mostly removed before the compounding/polishing step.

I thought about single stage paint too. Do you know if there is a way to determine single paint vs multi-stage?

Another thing just hit me. In the same thread there was a mention that this paint was "soft." So the same theory applies, if the clear coat covers the paint, why does the strength of the paint matter?

Mantilgh
06-16-2015, 12:35 PM
One way to determine if it is single stage or clear coated it to use a light colored cloth and some polish on test spot and see if you get color transferring to your cloth or applicator. Or a dark cloth on a light color paint.

It was probably single stage black paint which is know to be soft. There are also soft and hard clear coats though

LSNAutoDetailing
06-16-2015, 02:08 PM
I thought about single stage paint too. Do you know if there is a way to determine single paint vs multi-stage?

Another thing just hit me. In the same thread there was a mention that this paint was "soft." So the same theory applies, if the clear coat covers the paint, why does the strength of the paint matter?

Start with this thread:
The Secret to Removing Oxidation and Restoring a Show Car Finish to Antique Single Stage Paints (http://www.autogeekonline.net/forum/how-articles/25304-secret-removing-oxidation-restoring-show-car-finish-antique-single-stage-paints.html)

They may have meant the clear was soft, depends on the manufacturer. By nature, single stage is soft...

Clear-coats are baked at the factory at very high temps before any interior or wiring is added to the car. This is why they can harden the clear. A quick cure. Great strength, but hard to get out defects.

Bodyshops can't bake at those temps, thus the paint & clear takes time to cure. Leads to a softer clear-coat. The advantage is it's easier to get out defects.

trekkeruss
06-16-2015, 02:09 PM
Another thing just hit me. In the same thread there was a mention that this paint was "soft." So the same theory applies, if the clear coat covers the paint, why does the strength of the paint matter?

It matters because it determines what pads and/or polishes you need to use, and how long a polishing will take. A soft paint will correct easier and faster.