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Method for fixing deep scratches and rock chips

207K views 118 replies 81 participants last post by  naudiold 
#1 · (Edited)
I have good luck with this method. As you can see, this time I had a nice deep scratch to the primer. Both of these could be felt with the fingernail, however the one on the left is down to the primer.


The primary tools I use for deep scratches are:
~Random Orbital
~3 foam pads
~1600 Grit wet/dry sandpaper
~2000 Grit wet/dry sandpaper
~Spliced toothpicks (paint brush)
~Pencil with a good eraser

Products for this type of scratch/gouge:
~Griots Machine Polish #1 (Gritty, but not rubbing compound variety!)
~Griots Machine Polish #2 (Medium polish)
~Griots Machine Polish #3 (Mild Polish)
~BMW matching Paint




Clean the area on and around the surface area you're to work on. Use rubbing alcohol on a cotton cloth to ensure all the wax is removed from the work surface. Cut the tip of a toothpick down to a point. Wet the toothpick end with BMW color matching paint. Apply at least 3 thin coats, allowing 30 min to dry between applications. Allow the paint to dry over night.



Using first 1600 grit, then finishing with 2000 grit sandpaper, cut a small square that will wrap around the end of a pencil with a good eraser head on it for padding. Tape the sandpaper on the pencil eraser. Have ready a small dish with water and wet the sandpaper-tipped pencil. Begin working the area of dried paint in linear motion for linear scratches, circular if you're touching up rock chips.




Cont. next post:
 
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#94 ·
How do I access the original pictures for this? I have an 05 volvo that was just hit with salt pretty bad, and have many little "chips" in my hood that need some attention as well as a 2" long scratch/dent from a rock. Im selling the car as soon as I take delivery of my new BMW in the next few months! Any suggestions for removing the small dent/2" scratch in the paint?

I have the OEM touch up paint, and am a little nervous about the whole process and would liek to have the pictures as well as the tutorial available when I do a small "test" run.

TIA!
 
#99 ·
Dr Colorchip

I have also tried the Dr Colorchip and found similar results to the Langka - its very tough to get the paint removed just enough to stay flat without removing too much. Especially when you have light scratches that don't hold the paint well.

That said, the Dr Colorchip paint is nice and thin and dries within minutes, which is nice.

I am thinking that painting over a thin scuff or scratch, and then wetsanding to make it smooth, might be a better and cheaper option.

I'll keep trying the Dr Colorchip to see if I can improve my technique.
 
#100 ·
I have also tried the Dr Colorchip and found similar results to the Langka - its very tough to get the paint removed just enough to stay flat without removing too much. Especially when you have light scratches that don't hold the paint well.

That said, the Dr Colorchip paint is nice and thin and dries within minutes, which is nice.

I am thinking that painting over a thin scuff or scratch, and then wetsanding to make it smooth, might be a better and cheaper option.

I'll keep trying the Dr Colorchip to see if I can improve my technique.
hey hogan can u update us after you improve your technique with some pictures? i need to get some scratches out too and am considering to try out this drcolorchip. thanks!
 
#101 ·
I have tried it all when it comes to chips, old school fill and sand, air brush, langka, dr colorchip. Mind you, I am picky.

While my favorite technique for larger chips in small quantities is the old fill and sand (I use the eraser/polish technique often spoken off)... it really does not take all that long. I had a different issue on one of my cars. The edge of the hood on my 7 looked like some one had ran a sand blaster over it. Hundreds of very small chips. You could only see them from a few+ feet away and to really make it obvious, you needed to get down and sight along the panel. No way was I going to fill each and everyone by hand and finish out with my preferred technique.

Enter Dr ColorChip. Following the directions to the letter, I tried is on a small area on my hood. WOW. Could not believe the difference. All those tiny 'chips' virually disappeared. The larger ones still where concave but you could hit it again to build it up (that works) or resort to the old method. Either way, it saved me huge amounts of time... or a trip to the body shop. Now, you really have to look much more closely to tell that they where ever even there.

Bottom line, for large amounts of very small chips... give it a try.
 
#103 ·
If someone could take some time to make a video or post pics on the DIY Eraser, Polish technique (old pics no longer visible) that would be greatly appreciated.
+1

Thanks.
 
#106 ·
OK, this thread used to be 5 pages deep. Anyway, DetailDan, Big A, and others, if you read this maybe you will respond otherwise I will go to your display threads and post. I have a vertical scratch to the primer. I have read this instruction set over and over so I think I have it. Yes, I have a rotary. The scratch is vertical above the passenger rear wheel well about 6 inches from the edge up in the middle of the wheel well. My questions are: When does the clear go on? Since it is a vertical scratch do I need to leave the paint thick? Does the bottom of the scratch need prepping other than to clean with alcohol? Any need to use primer? No, it is not down to the metal but close. It seems to me that if clear is not used then there will always be a shadow.

TIA
 
#108 ·
OK, this thread used to be 5 pages deep. Anyway, DetailDan, Big A, and others, if you read this maybe you will respond otherwise I will go to your display threads and post. I have a vertical scratch to the primer. I have read this instruction set over and over so I think I have it. Yes, I have a rotary. The scratch is vertical above the passenger rear wheel well about 6 inches from the edge up in the middle of the wheel well. My questions are: When does the clear go on? Since it is a vertical scratch do I need to leave the paint thick? Does the bottom of the scratch need prepping other than to clean with alcohol? Any need to use primer? No, it is not down to the metal but close. It seems to me that if clear is not used then there will always be a shadow.

TIA
Am I the only one searching far actual before and after shots of chips on a car?

Online videos are low quality and only "appear" to work. I have yet to see high quality before and after video/photos with a 50/50 panel test to show this.

Anyone?
 
#110 · (Edited)
+1 on Langka

A few notes before purchasing though
1) I found I did not need to buy the full $40 paint chip repair kit, that merely the Blob Eliminator ($20) and some of the micro brushes. A credit card covered with a cotton tshirt, combined with rubbing alcohol to prep the area, and a paint sealant of your choosing work just as well as what's included in the full kit.

2) You must purchase the touch up paint stick from BMW or other aftermarket maker of touch up paints to use the Langka product.

3) Since I have a metallic paint, Langka recommends the "wet" method of applying their product which requires very careful, light passes of the shirt-covered card to spread a drop of paint into the chip/scratch without pulling the paint out of the scratch. I found BMW touch up paint became tacky so quickly, that I just created huge blobs and smears that took forever to eliminate. Instead, I used a hybrid method of the Colorchip dab/smear technique (dab of paint at one edge of chip/smear with bare or nitrile-gloved finger pulling paint into the chip), but also Langka's "wet" Blob Eliminator method to near perfection in filling almost 200 chips in my hood and doors with only the two largest chips showing any sign of repair and even that was negligible.

4) If using the "wet" method, DO NOT LET SMEARED PAINT DRY MORE THAN JUST A FEW MINUTES!!! Otherwise you will be reacquainted with the term "elbow grease". And if you have more than 50 overdry chips to Eliminate, YOU will be the one Eliminated (think hand waxing your entire car x5).

5) Trust the process. After several chips, I discovered how aggressive I could be removing blobs. Pretty firm at first, then lighten the pressure as the blob of paint dissipates and vanishes to reveal a professional looking repair. I could not see one of the 150 or so chips I repaired, even in bright sun or under fluorescent lighting.

Looks greats for small to medium chips. Anything larger than a pencil eraser may take a few attempts to build up enough paint and then you're left with a filled chip with matte-appearing paint in a chip (quite unsightly) and quite possibly better left for the body shop. THINNNNN application of clear coat included with the BMW touch up stick made for an adequate, but not invisible repair.

Langka was not great for narrow scratches down to the primer as the TU paint would not adhere to the groove and kept getting pulled out of the repair area. Repeat process starting at step 2 until you get it just right.

Well worth the cost vs the shop in my case.
 
#114 ·
Nice thread. Subscribing. For the very light scratches...like a white scratch on a black car that you can't feel, I find that Meguire's 2X scratch remover works better than Nu Finish Scratch Doctor. It seems the Nu Finish product is a little finer so doesn't remove the scratch. Neither one leaves a haze or swirl marks.
 
#116 · (Edited)
I think I am going to attempt to repair a scratch on my 640i GC (pic of scratch attached) using OP's method. Other than cleaning the scratch area, should any other prep work be done before applying the OEM touch-up paint? The edges on my scratch are rough and I'm wondering whether a light sanding before applying the OEM touch-up paint would be beneficial or detrimental. Also, it appears that the scratch is all the way through the clear-coat but I was wondering whether it might be a good idea to first attempt a sand and polish before attempting to apply touch up paint (and then sand and polish).
 

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