Method for fixing deep scratches and rock chips

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:

This is what the surface looked like after sanding(Pic below). You may panic somewhat your first time doing this, but rest assured, high blood pressure after scratching up your clear coat is normal. We’ll work this out with Machine Polish.


Beginning with Machine Polish #1, use the random orbit polisher up and down, left and right over the area. Finish up with Machine Polish #3, using a separate pad for each. Your finish will be as good as new, with a slight hairline “fracture” where you did the touch up.


I do not use the clear coat that comes with the BMW paint kit nor the application brush. 3 or 4 coats of paint is plenty, and the clear coat topping seems like a waste since you end up sanding off the high spots anyway.

Don’t be afraid to try it if you have the proper tools!

And if your friends come over, don’t give them fish, teach them to fish! I put Mark to work (mv945) with the PC and machine polishes on his Jet Black M3 after he had an encounters with wood on the roadway, kicked up along the side of his finish. The Machine polishes and the PC took just about all evidence of any scratches (since these scratches did not penetrate to the primer)

Originally Posted by Guest84

This is what the surface looked like after sanding(Pic below). You may panic somewhat your first time doing this, but rest assured, high blood pressure after scratching up your clear coat is normal. We'll work this out with Machine Polish.


Beginning with Machine Polish #1, use the random orbit polisher up and down, left and right over the area. Finish up with Machine Polish #3, using a separate pad for each. Your finish will be as good as new, with a slight hairline "fracture" where you did the touch up.


I do not use the clear coat that comes with the BMW paint kit nor the application brush. 3 or 4 coats of paint is plenty, and the clear coat topping seems like a waste since you end up sanding off the high spots anyway.

Don't be afraid to try it if you have the proper tools!

And if your friends come over, don't give them fish, teach them to fish! I put Mark to work (mv945) with the PC and machine polishes on his Jet Black M3 after he had an encounters with wood on the roadway, kicked up along the side of his finish. The Machine polishes and the PC took just about all evidence of any scratches (since these scratches did not penetrate to the primer)

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I have a question about this technique. I'm not sure if the OP is still on this site but I would appreciate a response from anyone in the know.

There was mention of not using clear coat. I assume that the scratch was filled in with paint up to the level of the clear coat and then polished. If so, isn't that why the 'micro hairline fracture' is visible. You basically have a clear lacquer touching a paint and hence a line will be visible ?

If I were to use clear coat after filling in the paint, how should I do this correctly ? Would I first have to 'etch' some of the over filled paint out and then put the clear coat on ?

Thanks for such a good description of this process. Very informative.

Very good post Rip


My method differs only in polishes used as I use 3M products.
I never used clearcoat either.

This is a great post. Making it sticky as I'm sure many will be taking on this sort of project as the weather improves.

Originally posted by alee
This is a great post. Making it sticky as I'm sure many will be taking on this sort of project as the weather improves.

I certainly will be, if summer ever gets here. Thanks Rip!

Excellent post Ripsnort!

Cosmic... I was going to post an inquiry about precisely this topic since I have rock-chip-o-rama on my front bumper and hood that needs attention, and have never done this before. Like a prayer answered, you provided the precise details with great pictures. Thanks Rip!

Not to give you a hard time, Rip, but there seems to be a mystery blemish in your photos further back from the subject scratches along the fender line that suddenly appeared after you sanded, then looked as if it had been sanded in the final polished photo... What happened, did you accidentally drop something on the fender?

The tried and true process, noted many places on the web, works great! Nice job on photo documenting it Rip. I use a "00" (very fine) paintbrush instead of a toothpick myself. Another successful job complements of Griots products

Originally posted by RKT BMR
Not to give you a hard time, Rip, but there seems to be a mystery blemish in your photos further back from the subject scratches along the fender line that suddenly appeared after you sanded, then looked as if it had been sanded in the final polished photo... What happened, did you accidentally drop something on the fender?

LOL, no that "3rd scratch" is the reflection of something white in the background of the garage, you wouldn't believe it but I took 36 photos to document this and only used a handful...the mirror reflection was a pain with auto-focus on, I should have turned it off and gone manually, but alas, too lazy.

Thks for the kudo's all, I'm just passing the info passed onto me is all.

Many thanks to Rip for the use of his garage, PC, Griot's products, knowledge, and beer! The surface scratches I had on my M3 are all but invisible now, all I need to do is re-apply Zaino over the areas we worked on. Now I need to go buy my own Porter-Cable and make a visit to Griot's!

Originally posted by Ripsnort
LOL, no that "3rd scratch" is the reflection of something white in the background of the garage, you wouldn't believe it but I took 36 photos to document this and only used a handful...the mirror reflection was a pain with auto-focus on, I should have turned it off and gone manually, but alas, too lazy.

That's some shine dude!

Nice work. Glad to see I'm not the only random stone magnet.

At Homecoming you get to see how the BMW final inspection techs do it. They use a very small artists brush to layer VERY thin layers of paint IN the chip.

They keep doing this, letting it dry maybe a minute each layer, until the scratch is filled to the top, but not over filled. A quick rub with polishing compound and it is done and virtually invisible.

Originally Posted by Pinecone

At Homecoming you get to see how the BMW final inspection techs do it. They use a very small artists brush to layer VERY thin layers of paint IN the chip.

They keep doing this, letting it dry maybe a minute each layer, until the scratch is filled to the top, but not over filled. A quick rub with polishing compound and it is done and virtually invisible.

I would imagine if you do it for a living you'd become quite good at it over time...and the toothpick method I used , the toothpic is shaved down to basically what the tip of an artists brush is..however, this was my 2nd time doing this and I'm still a rookie..thus, excess paint.

Ahh this helps SOOO MUCH!!

I can't wait to apply this procedure to the front end of my car. All i need now is a buffer. Bah! Buffers are for children! I'll be a man, and use my HAND!

Where can I get 1600 and 2000 grit sandpaper at? I just got back from Lowe's and could only find 80-600 grit paper by 3M.

Originally Posted by ranch4x4

Where can I get 1600 and 2000 grit sandpaper at? I just got back from Lowe's and could only find 80-600 grit paper by 3M.

Pep boys has 1600 and 2000.

This is the generally recommended procedure for fixing deep scratches and chips. The main problem with it is that its anything but quick.

Ive found Ive been able to eliminate the most time consuming part of the process; the sanding. The idea is you need to knock down the touchup 'blob' youve created, by building up the touchup layer. Ive found there is a product called 'Langkfa' which a a chemical solvent. The idea is, after letting the touchup dry for just about a half hour, til its dry to the touch, you take the thin plastic card in the kit, wrap it tightly in a fine cotton fabric (not terry which will tend to take the touchup out of the chip), apply a few drops of the Langkfa solvent to the cotton wrapped card, and gently go back and forth over the touchup until the 'blob' is no longer a blob, and is level with the surrounding paint. No more or youll remove the paint from the chip. When thats done, just go over the area with a polish, and youre done. After youre finished, and the paint has cured, then just appy wax to the area. I find I can do chips and scratches with this method in just a few minutes longer than it takes to allow the touchup to dry. I do all my touchups now this way, and believe me, its every bit as effective as the old wet sanding technque for 'knocking down the blobs'!

Originally Posted by paul e

This is the generally recommended procedure for fixing deep scratches and chips. The main problem with it is that its anything but quick.

Ive found Ive been able to eliminate the most time consuming part of the process; the sanding. The idea is you need to knock down the touchup 'blob' youve created, by building up the touchup layer. Ive found there is a product called 'Langkfa' which a a chemical solvent. The idea is, after letting the touchup dry for just about a half hour, til its dry to the touch, you take the thin plastic card in the kit, wrap it tightly in a fine cotton fabric (not terry which will tend to take the touchup out of the chip), apply a few drops of the Langkfa solvent to the cotton wrapped card, and gently go back and forth over the touchup until the 'blob' is no longer a blob, and is level with the surrounding paint. No more or youll remove the paint from the chip. When thats done, just go over the area with a polish, and youre done. After youre finished, and the paint has cured, then just appy wax to the area. I find I can do chips and scratches with this method in just a few minutes longer than it takes to allow the touchup to dry. I do all my touchups now this way, and believe me, its every bit as effective as the old wet sanding technque for 'knocking down the blobs'!

Excellent, I will check the product out. Off to do a google search..

Edit: "Your search - Langkfa - did not match any documents.
No pages were found containing "langkfa".

You sure thats the name of the product?

Originally Posted by Ripsnort

Excellent, I will check the product out. Off to do a google search..

Edit: "Your search - Langkfa - did not match any documents.
No pages were found containing "langkfa".

You sure thats the name of the product?

It's langka:

http://www.langka.com

Originally Posted by paul e

This is the generally recommended procedure for fixing deep scratches and chips. The main problem with it is that its anything but quick.

Ive found Ive been able to eliminate the most time consuming part of the process; the sanding. The idea is you need to knock down the touchup 'blob' youve created, by building up the touchup layer. Ive found there is a product called 'Langkfa' which a a chemical solvent. The idea is, after letting the touchup dry for just about a half hour, til its dry to the touch, you take the thin plastic card in the kit, wrap it tightly in a fine cotton fabric (not terry which will tend to take the touchup out of the chip), apply a few drops of the Langkfa solvent to the cotton wrapped card, and gently go back and forth over the touchup until the 'blob' is no longer a blob, and is level with the surrounding paint. No more or youll remove the paint from the chip. When thats done, just go over the area with a polish, and youre done. After youre finished, and the paint has cured, then just appy wax to the area. I find I can do chips and scratches with this method in just a few minutes longer than it takes to allow the touchup to dry. I do all my touchups now this way, and believe me, its every bit as effective as the old wet sanding technque for 'knocking down the blobs'!

hi Paul - so I want to use this product, I would have to buy touch up paint separately? or just buying the entire kit is sufficient? thanks!

I had a chance to use the Langka products yesterday. My analysis summary:

Great product for deep rock chips and deep scratches. Works as advertised, removing excess paint.

Its "okay" for scratches that penetrate thru to the primer (white finish showing, can feel it with fingernail) but in most cases one must again put touch up paint on and remove it again, until you get just the right removal of the paint with the Langka product. I found myself removing all the paint a couple of times in the shallow scratches, even with a light touch.

Overall, I'd say this product doesn't exactly replace the old fashioned method of sanding in *some cases* of shallow primer scratches, but its a "must have" on the detail shelf for those quick and dirty rock chips jobs.

I tried to photograph the "stages" I went thru, and before and after results, but as you can see, the reflection of my Jet Black is just too overwhelming to see anything. The pics below are the product ($44 with shipping) and a "Before" pic of paint applied to a shallow scratch. No "After" pic because frankly there was too much reflection, and this type of shallow scratch was difficult to see to begin with.
The full product contains a pre-paint cleaner (Alcohol would have been a good substitute), the "Blob" remover, a "Paint sealer" (P21S would have worked in a similiar fashion), a small paint brush (I had a few of these already) and a card ( a credit card would have been sufficient). I'd recommend getting just the "Blob" remover if you plan to purchase this, and use the products I suggested above for replacements.

Where do I find these items? Are there acceptable alternatives?