View Full Version : Wet Sanding Reveals Strange Ovals in Paint?! (Pics Within)
DownFlyer
09-10-2008, 04:36 PM
OK I`m really stumped on this one.
I was following the Paint Clinic article to fill in a stone chip on my hood. Today I was wet-sanding down the overfill area with 2000 grit sandpaper.
Here is the chip before re-filling it:
http://img93.imageshack.us/img93/9610/img2030ahi1.th.jpg (http://img93.imageshack.us/my.php?image=img2030ahi1.jpg)
http://img93.imageshack.us/img93/3186/img2029aoe6.th.jpg (http://img93.imageshack.us/my.php?image=img2029aoe6.jpg)
Now I wet-sanded and these weird ovals appeared near the chip. Is this a remnant of some old chip-repair from the previous owner? I am really confused.
http://img231.imageshack.us/img231/4247/img2040abm9.th.jpg (http://img231.imageshack.us/my.php?image=img2040abm9.jpg)
The only thing I can think of is that I removed the old touch-up paint from the chip using a very small amount of lacquer thinner so I could re-start it properly after reading the Paint Clinic article. I`m pretty sure that I didn`t dab it anywhere else. Though I don`t even know if that could cause something like this.
What the heck is going on here? Did I mess up??
It looks like you sanded way too much. Are you sure you used 2000 grit?
BigJimZ28
09-10-2008, 04:48 PM
sorry dude that is primmer
you sanded off the paint
DownFlyer
09-10-2008, 04:52 PM
It looks like you sanded way too much. Are you sure you used 2000 grit?
Without a doubt, I only bought 1500 and 2000 grit. I re-checked and it is definitely 2000 grit. The sandpaper itself is almost smooth like paper.
David703
09-10-2008, 04:58 PM
the smaller greenish ring looks to be the same color as the green primer at bottom of the chip. The other ring could be where the clear and base coat meet..
My vote is that u wet sanded into the primer. Did u buff it yet?
Why did u wet sand such a large area? If I filled that chip I would only try to wet sand the chip.
It could be the second layer of a previous touch up, but if you were to purposely sand through your paint, that`s exactly what it would like.
Consider it ruined and try polishing it. Maybe you and I both are completely wrong...If you did sand to far, you can`t screw it up much more by trying to buff it out again.
Edit: Looking at the pictures some more, I`m really leaning towards you pusing to hard with your middle finger as you were trying to sand it, but like the poster above me mentioned, that`s way to much to sand in the first place. I would sand no more than 0.25" past the EOP of the chip.
DownFlyer
09-10-2008, 05:04 PM
the smaller greenish ring looks to be the same color as the green primer at bottom of the chip. The other ring could be where the clear and base coat meet..
My vote is that u wet sanded into the primer. Did u buff it yet?
Why did u wet sand such a large area? If I filled that chip I would only try to wet sand the chip.
That ring really isn`t so green ... it`s a trick of the camera.
I have not buffed it yet.
The chip is actually pretty small and honestly I was a little clumbsy with the sand paper and the lighting was poor so I did not accurately see the right spot. I probably should have removed the hood deflector first so I could get at it more easily.
DownFlyer
09-10-2008, 05:05 PM
It could be the second layer of a previous touch up, but if you were to purposely sand through your paint, that`s exactly what it would like.
Consider it ruined and try polishing it. Maybe you and I both are completely wrong...If you did sand to far, you can`t screw it up much more by trying to buff it out again.
Edit: Looking at the pictures some more, I`m really leaning towards you pusing to hard with your middle finger as you were trying to sand it, but like the poster above me mentioned, that`s way to much to sand in the first place. I would sand no more than 0.25" past the EOP of the chip.
Fair points, though I`m wondering why it was such a nice round oval. If I sanded into the primer, then wouldn`t it have been a different and much more rough shape?
Fair points, though I`m wondering why it was such a nice round oval. If I sanded into the primer, then wouldn`t it have been a different and much more rough shape?
Not necessarily. Judging by the color of the car (I don`t know what the car is, but I haven`t seen a *new* color like that in forever), I`d say it`s what - 10-15 years old? If I`m right, did you measure the paint thinkness before hand? Painting several years ago is nothing like it was today. Paint thickness could have been a mess way before you started tearing into it.
My honest-to-goodness assumption from looking at the shape of the entire part you sanded, is that you had your pointer finger over the chip, as a control finger, and you were unintentionally using too much pressure with your middle finger. Rub your hand like your sanding with it on your desk, trying not to put too much pressure down with your pointer finger and you`ll see what I mean. This is why you sand very, very little in cases like that, and use like no pressure, especially since the paint you intended to sand down was fresh and most likely softer than the original.
I`m no pro, hell I`m not even an amature, but I`ve screwed up similar projects (thankfully no cars) and that`s exactly what it looks like.
It may still be repairable, but I`d buff it out before thinking about doing anything else.
Lumadar
09-10-2008, 05:39 PM
My vote is you sanded straight down to the base coat. Bummer :/
SHhhhh
09-10-2008, 05:40 PM
the smaller greenish ring looks to be the same color as the green primer at bottom of the chip. The other ring could be where the clear and base coat meet..
My vote is that u wet sanded into the primer. Did u buff it yet?
Why did u wet sand such a large area? If I filled that chip I would only try to wet sand the chip.
+1
Looks like you sanded entirely too much.
DownFlyer
09-10-2008, 05:41 PM
This is not some old car... it a model 2007 year vehicle. I don`t have a paint thickness measuring device.
OK so I buffed the thing out using SFX-1 and SFX-2... I got out a bright flashlight and it does appear that the OEM paint is too thin in that area and under bright light what appears to be primer is showing through.
I wrapped the sandpaper around a rubber eraser as described in the Paint Clinic article and honestly I was not too worried about sanding a larger area. Look at the pics (http://autopia.org/forum/guide-detailing/80224-paint-clinic.html) shown, he sands quite a large area! I was not overly careful with the pressure either because it was such fine grit sandpaper and the article said nothing about oversanding, so I thought you`d have to be sitting there sanding it vigorously for an hour before 2000 grit would cut though the factory paint.
Any expects want to comment on whether I should re-touch this up? Or have I screwed it up enough that it should be repainted at a body shop?
SHhhhh
09-10-2008, 05:41 PM
found it :sign
DownFlyer
09-10-2008, 05:42 PM
Where is this Paint Clinic article you are referring to ?
Automotive Paint Repair Clinic by DavidB (http://autopia.org/forum/guide-detailing/80224-paint-clinic.html).
This is not some old car... it a model 2007 year vehicle.
Lol, my bad man. What model car did you get with a purple tint? Last car I remember in a color similar was the old arse Monte Carlo`s, I think...