Did I accidentally discover touch-up paint on my friend's Miata?

[jasonb42]

Hi, all! My friend has a 1993 Mazda Miata in red, and he wanted me to do a test area to see how the car would look after a quick polish. After polishing, we got an idea of how the paint would react, and called it a day.

After he left, he called me and said he had a dark blob on his hood near where I polished. He sent me this picture:

63672

It isn't terribly noticeable, but it's definitely there and it was definitely caused by the polishing.

I had polished in the corner of the hood next to the pop-up headlight, but not on the headlight cover or above it where the blob has formed. There was some polish that got in that area that I removed.

He thinks it could be an area where touch-up paint was once applied, and I had either buffed it off or spread it unevenly. I think that may be the case, or that it is simply polish that did not get broken down all the way. I'm also not super experienced with paint correction yet, so both of these diagnoses could be wrong. I feel even worse that this happened while working on someone else's car.

1. Have any of you encountered this before? If so, what is it and what can be done to remove it, or what steps can be taken to fix it?
2. If it is touch up paint, can it be polished more to better blend with the surrounding paint?
3. If it is polish that is not broken down, what is the best method to lift the residue without damaging the paint?

Thanks!

[LSNAutoDetailing]

Hard to tell from the low-res photo. It's quite possible it was a touch up paint spot, but unlikely polishing it would remove it. I've polished over touch-up paint many times.
One possibility is it's not uncommon to remove layers of defects only to expose imperfect paint. After scratches and swirls are removed, the light does not refract off of those and draws your eyes to defects not removed by polishing. Two instances of such phenomena is solvent popping (which while the hardening solvents in the paint off-gassed without being released and stay under the clear-coat) and sand pitting. Both look almost identical. Generally before paint correction these two conditions almost are invisible. After correction, they stick out like a soar thumb.

My suggestion is take a closer looks in person at the vehicle. Run your finger nail over the defect, if there is a divot your finger will catch it, thus it was a rock chip filled with some touch-up. Get yourself a dr color chip kit and follow the instructions and dozens of you tube videos to reapply touch-up paint. Great thing about Dr color chip is you can't mess up. You can always use seal act (within reasonable amount of time) to remove a touch up that you don't like.

p.s. Welcome to the forum!

[LEDetailing]

Was the paint single stage? I’m guessing it is. I drove a 1991 Miata in British racing green which was single stage paint.

If it is single stage paint. Single stage paint is prone to staining.

Here is link to a thread regarding the issue:

Dark spots/stains in classic single stage (https://www.autogeekonline.net/forum/ask-mike-phillips-your-detailing-questions-/98823-dark-spots-stains-classic-single-stage.html)

[LEDetailing]

My guess is the stain was probably already present, you just cleaned/polished the surrounding paint and now the staining is more obvious. Just a hunch.

[DaveT435]

My guess is the stain was probably already present, you just cleaned/polished the surrounding paint and now the staining is more obvious. Just a hunch.

Definitely agree with this. Nothing you did would make the paint do that. Once you remove scratches and swirling light reflects off the paint differently so it's visible.

[Coopers ST]

Was the paint single stage? I’m guessing it is. I drove a 1991 Miata in British racing green which was single stage paint.

If it is single stage paint. Single stage paint is prone to staining.

Here is link to a thread regarding the issue:

Dark spots/stains in classic single stage (https://www.autogeekonline.net/forum/ask-mike-phillips-your-detailing-questions-/98823-dark-spots-stains-classic-single-stage.html)

Yes it would be unless it's been repainted. If it wasn't single stage and it was repainted who knows what the condition and quality of the repaint would be.

[jasonb42]

Good news, maybe: I stopped by so we could inspect the paint after he got off of work, and to our delight (and simultaneously, horror), the dark spot had disappeared; there isn't a trace of it. The paint looks great where it was polished though!

Not too sure what to think of the sudden disappearance. We're going to check again in the sunlight tomorrow, but hopefully it's gone for good. Still curious as to what happened in the first place; I think I'll read up on that dark spots/stains thread. I appreciate all of your input though! Thank you all!

[LEDetailing]

Good to hear.