# Stone chip repair...



## M3_Crazy_Dude (Dec 17, 2008)

Hi, 

just a quick question regarding how much to wet sand a stone chip repair. 

When sanding and the paintwork hazes, should I still see the outline of the stonechip I’ve repaired ? I cannot seem to feel that the repair is sitting proud of the surface, so wondered if that was far enough or if I should sand until the hazes is uniform?

Thank you for any help.


----------



## bellguy (Feb 4, 2021)

Very difficult without pictures, I have over the years done many chip repairs but you have to be very careful to not sand through the clearcoat.
Stone chips need flatting off with 2500 wet and dry before any paint put in the chip, if you do not do this when you come to polish etc you will see mapping, which is the outline of the chip and at that point it’s all to easy to blast through the clear.


----------



## M3_Crazy_Dude (Dec 17, 2008)

Thank you for the response - first time I've done this, I did not wet sand before putting the paint in 

Photos which hopefully help...


----------



## bellguy (Feb 4, 2021)

Ok that’s mapping so now the only way forward is to do a smart repair over the offending areas as you will not get rid of the darker outlines (mapping)
Not what you wanted to hear I am sure.
How big are these areas as it’s difficult to tell


----------



## M3_Crazy_Dude (Dec 17, 2008)

bellguy said:


> Ok that's mapping so now the only way forward is to do a smart repair over the offending areas as you will not get rid of the darker outlines (mapping)
> Not what you wanted to hear I am sure.
> How big are these areas as it's difficult to tell


Thanks, they are on quite a small area on the rear bumper.

So in effect I need to now put touch up paint over the mapping bits and then go through the wet sanding process again?

That's ok, gives me a chance to get on first name terms with my rear parking sensors :wall:


----------



## ridders66 (May 24, 2019)

M3_Crazy_Dude said:


> Thanks, they are on quite a small area on the rear bumper.
> 
> So in effect I need to now put touch up paint over the mapping bits and then go through the wet sanding process again?
> 
> That's ok, gives me a chance to get on first name terms with my rear parking sensors :wall:


If they are on a small area on the rear bumper, before going any further, I would recommend that you polish up the area with a two stage polish. You may lose the mark, or get it to a standard that you are happy with. Once you start adding more paint, you're making the repair larger and therefore more noticeable. It is always better to keep a repair as small as possible.
Regarding flatting off before touching up, in my experience that is not always necessary. I remember when I detailed my first Enzo Ferrari, there was a huge stone chip on the centre of the front nose cone. It was finished in Rosso Corsa. I simply filled the chip in with paint, once set I flatted it off and polished it in. I could not even see it myself. I think with metallic finishes it is always much more difficult to achieve a high standard rather than when touching up a flat colour.


----------



## M3_Crazy_Dude (Dec 17, 2008)

Managed to work it out...

Re mapping of stone chips, I used sand paper on a pencil and that sorted it 

Did the machine polish again and it looks great now !

Thanks for all the help


----------



## JB052 (Mar 22, 2008)

M3_Crazy_Dude said:


> Managed to work it out...
> 
> Re mapping of stone chips, I used sand paper on a pencil and that sorted it
> 
> ...


What grade paper did you use?


----------



## M3_Crazy_Dude (Dec 17, 2008)

JB052 said:


> What grade paper did you use?


I used 3000 grit to start the process, then found it took ages to sand down, so switched to 2500 grit which helped.

For the stubborn mapping I used 2000 grit on the end of pencil (which has the rubber) and focused very carefully on working between the mapping lines...that seemed to do the trick. You could see the mapping reduce on the chip every time I wiped it down with a cloth.

Very tedious to do and still some spots I need to finish off, just cannot face the boredom of doing it yet!


----------

