Burning Paint with PC 7424 - Page 2

lbls1 · 07-04-09, 03:13

You are not alone. I had a similar mishap (Not due to the pc or pad!) with my new babe, and I am having it repaired on Monday. Its a shocking thing, but I was able to stay calm and realize that its an object and not a person or flesh, and it can be repaired. What will most likely happen, the body shop will need to do a color sand repair, and (if the damage is localized) do a re-clear of the bumper (?) or area affected.

But yes, given the right circumstances a pc can burn thru paint!

efnfast · 07-04-09, 10:06

You can burn paint with anything, but to do that much damage with a pc and a blue pad and 85, either you must have been doing something really wrong, like sitting ontop of it in 1 spot for a minute or so, or there was a problem from the factory.

If I had to take a guess, and it's just my guess, I'd say a problem from the factory - on one of my test bumpers something similar happened.

I did 1 pass with a cyclo, orange pad, and menzerna power gloss, next to no pressure, yet somehow I totally removed the clear, the paint, and went right down into the primer.

At first I thought this was how strong power gloss was, but this made no sense, so I went about 10'' over on the panel and, with maximum force, pressed the cyclo down and left it riding in 1 spot for a good 40 or 50seconds. removed it and no paint burn or any type of damage. So if I could apply 100x (okay, that's my estimation, lol) the force and heat 10'' away, it certainly wasn't the cyclo's fault, my fault, or anybody but the factory's fault.

Quote:

Originally Posted by GoudyL

Do not machine polish plastic/fiber glass panels. The machine will be putting alot of energy into a very small area, and non-metalic panels do not conduct heat.

Look at all the corvettes and cobra kit cars that melt when you machine polish them

Scottwax · 07-04-09, 10:40

Quote:

Originally Posted by GoudyL

Why are you machine polishing a brand new car?

The paint doesn't reach it's full hardness for about 90 days after the build date.

Most car manufacturers will spot wetsand and polish cars right out of the oven.

The problem wasn't that the paint was polished too soon but incorrectly.

lbls1 · 07-05-09, 12:01

Post #14 is right; My signature car's body panels are 75% composite, and I have polished them in the sunlight (not direct, however) a few times w/o issue.

Off the bat I would either suspect a defect in factory paint (it does happen!), a pad that could've went awry, a mishap, or a number of mysterious things if the OP is claiming that he/she did not do anything intentionally wrong.

efnfast · 07-05-09, 12:29

Quote:

Originally Posted by Scottwax

The problem wasn't that the paint was polished too soon but incorrectly.

Is there something though from the pictures that makes you certain it was polished incorrectly and not a problem from the factory?

For example, if you look a post or two above yours (my last one), you can see what, on a previously-never-before-polished surface, a cyclo did in 1 pass (maybe 10seconds of work) - chewed through the clearcoat, the paint, and right into the primer. Bet you've never seen that before when you used one, heh.

Setec Astronomy · 07-05-09, 07:10

efnfast...aren't you the other guy that did this, on a rocker panel? Are you saying that was a factory defect? On the one hand, there's no two ways about it, plastic panels conduct less heat. On the other hand, I'm sure there is some variation in paint adhesion, and if you happen to be on one of those spots, you know...wrong place wrong time. Plus, they DO repair things at the factory when they don't come out right, so it's possible in both of these instances it was the combo of a not-quite-to-par spot that got heated up.

The Corvette example is a little different because the glass fiber in fiberglass/SMC makes the panels more thermally conductive than the polyurethane/etc. bumper covers.

Got More Wax · 07-05-09, 08:14

I'm going to agree with SB here. At best, I would say you have an insurance claim. This is just another unfortunate example that one can in fact induce damage with machines aside from just the rotary.

Good Luck and let us know how it turns out.

Andy

Quote:

Originally Posted by SuperBee364

It's definitely a burn, or more accurately a "melt." The sun heating up the black bumper didn't help any, either. As you now know, the plastic parts of a car are much easier to damage when polishing. They just won't take heat like metal. Make sure you always keep the pad moving across the paint... I'm guessing that you held the polisher stationery for a few seconds with some pressure on it.

What really sucks is there isn't any warning when this is about to happen. You go from happy to sad immediately. Hence the need to be really careful.

Man, I'm sorry about your new car, but I can't get behind the idea of trying to make the dealer pay for something you did.

SuperBee364 · 07-05-09, 09:14

Quote:

Originally Posted by efnfast

Is there something though from the pictures that makes you certain it was polished incorrectly and not a problem from the factory?

For example, if you look a post or two above yours (my last one), you can see what, on a previously-never-before-polished surface, a cyclo did in 1 pass (maybe 10seconds of work) - chewed through the clearcoat, the paint, and right into the primer. Bet you've never seen that before when you used one, heh.

Yeah, there is. You can tell that it is *melted*. Melting through a panel with a machine polisher just isn't a factory defect.

In your picture of your damage, it doesn't look like a melt at all. Two *different* types of damage, caused by two different things.

Scottwax · 07-05-09, 09:32

Quote:

Originally Posted by efnfast

Is there something though from the pictures that makes you certain it was polished incorrectly and not a problem from the factory?

For example, if you look a post or two above yours (my last one), you can see what, on a previously-never-before-polished surface, a cyclo did in 1 pass (maybe 10seconds of work) - chewed through the clearcoat, the paint, and right into the primer. Bet you've never seen that before when you used one, heh.

On that bumper, it simply looks like a combination of pressure and heat build up tore up the paint. It is possible there is a paint problem too, but even so, it probably wouldn't have been an issue if it hadn't been buffed hard.

Accumulator · 07-05-09, 10:35

Quote:

Originally Posted by GoudyL

Do not machine polish plastic/fiber glass panels. The machine will be putting alot of energy into a very small area, and non-metalic panels do not conduct heat..

Huh? Right, they don't conduct heat the same as metal panels, but that just means that you do them a little differently.

I've *NEVER* had a problem machine polishing plastic panels, let alone fiberglass. Never. Not on factory paint (freshly built or not), not on repaints (freshly done or not). Not with a rotary, a Cyclo, or a PC. Via PC/Cyclo it's easy; just a matter of feeling the panel after every few seconds of polishing until you learn how it goes (which is how you learn to do it by rotary too).

Paint can have defects. These can cause problems. And, well..[stuff] happens. But to never machine polish plastic panels...

lbls1 · 07-05-09, 12:45

^Tell 'em Accumulator. Damn hope my litte boo boo gets fixed right. It delayed my __________ job on the new material. I was set into knocking you out with that one. One of these days I suppose.....

Scottwax · 07-05-09, 01:16

Quote:

Originally Posted by Accumulator

But to never machine polish plastic panels...

I know, right?

I just ease up on speed and pressure when unsure. I can always increase one or the other a bit gradually and check the surface to make sure everything is okay. However, to lean on any paint hard and just hold the pad in place is asking for trouble.