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[cem_devecioglu]

all cars , inevitably will have stone chips or scratches.. 
 
and if the damage is deep and metal surface can be seen, resulting with rust..
 
painting whole part is the best solution but not economical.. however you can still get good results that chips and scratches will be hardly seen.. 
 
so I wanted to share some of my experiences ..
 
* STEP 1: first thing to do is learning the correct color code for your car.. they are located on door pillars or above above the radiator -plastic or under the boot... for omega http://www.youtube.com/watch?v=lwvIRlr-qfQ  if you dont use the original color code your success will be limited especially if its metallic because metallic colors tend to show every fault..     so a visit to paint shop with a paint mixing machine is necessary..  if the computer/machine dont have the code mixture info they have to prepare the mixture by trial which is not easy.. besides most codes have many different variants with different mixture amounts.. 
 
I recommend you buy minimum 250 grs of paint because color mixture formulas are on a 1 kg basis (here)  and if you buy very small portions like 50 grs ,the division of formula gives very small fractions that the machine cant measure and the shop cant weight the drops.. so you will have a distorted color tone.. 
 
after the mixture is done if you are not sure of the color tone, you can try it on test cards .. I strongly recommend you prepare/ have it prepared and checked on a sunny day.. because sunlight is the most strong light that you can distinguish between color tones and see the exact correct tone.. if you are over sensitive there are analysing/measuring machines that shows the color mixture but they are very rare and expensive..
 
and one warning for touch up color pens: they are not that successful as expected..
 
other items you will need: primer, primer hardener ( if needed) ,clear coat (laquer), quick hardener (laquer),  masking band, very tiny brushes  , cleaning thinner (synthetic) , selulosic thinner (buy good quality) , 2000 or 1500 grid sanding paper (and if you have a compressor and a spray gun thats better but not compulsory)
 
 
 
so buy them when you are at the shop.. 
 
so assuming you buy the correct color code at correct mixture ratios, we can pass to the next step..
 
 
* STEP 2: meteorology (even if you have a garage) .. the day you will work must never be rainy or windy.. especially if you will work outside.. so check meteorology.. when painting , high moisture is very risky.. and any dust will create problems
 
* STEP 3: clean the area with cleaning thinner  and let it dry for few minutes.. aim is to remove polishes and any dirt.. 
 

here is the anatomy of paint and the damaged area.. depending on its depth you may need to use also primer  if you can see the metal surface or rust.. 
 
* STEP 4: carefully examine the paint chip or scratch.. wet sand the sharp edges with 2000 to get a smoother surface.. but not down to base coat or bare metal   aim is to get a flat surface..  and if the chip is very big also make some small scratches inside with 1500.. if there is rust first you need to remove the rust and clean the area completely..  you can also use rust dissolving agents.. but you must also clean them..
 
* STEP 5: -Primer or base coat- if you will use a spray gun mask the edges of chip or scratch so that you will only fill inside (and also other areas-dont use old newspapers they are very dusty use nylon instead).. you have to apply several layers and need some dry up periods.. masking the area wont be necessary if you will do with brush..  if you will use brush add some celulosic thinner to paint so that your brush wont make traces (start with % 5-10 thinner and make some trials on paper) .. after painting let it dry ..  at least an hour (depends on temperature)    as the base coat will shrink you will need to apply several layers until the paint level comes very close or equal to clear coat.. in case there is excess wait until its completely dry and sand the excess part..
 
* STEP 6: apply laquer with brush or spray gun.. let it dry.. and correct the surface by lightly sanding it.. (dont take completely)..
 
then polish the area..
 
step 5 and 6 may take more than a day or several days.. but the longer you wait, the more sucessfull you will be.. because paint and laquer dries quickly at the surface but not inside..
 
here is a filled paint chip (around 4 mms in diameter) , the excess paint will be sanded after dry up.. and laquered

 
and the dust protection

 
 
 ps: ask your shop primer and laquer hardener adding ratios.. they are generally 3: 1 (hardener)  but may vary..
 
 
 
 
 
 
 
 
 

[omega3000]

Dust protection  Good idea though 
Now our weather is becoming colder and i need to touch in a few scratches from cats  quite a few on the boot now  i dont think its warm enough to use paint outside now so will start in summer when we have one week of heat 

There must be 20 cats in our street , all jumping on cars to keep warm at night ... the week before i waxed the boot and looks like the cats had a job of gripping when jumping up .. looks like a skating ring 

[cem_devecioglu]

Dust protection  Good idea though 
Now our weather is becoming colder and i need to touch in a few scratches from cats  quite a few on the boot now  i dont think its warm enough to use paint outside now so will start in summer when we have one week of heat 

There must be 20 cats in our street , all jumping on cars to keep warm at night ... the week before i waxed the boot and looks like the cats had a job of gripping when jumping up .. looks like a skating ring 

we have the same problem EMD.. big cats dont climb cars but smalls want to discover everywhere..   I could solve this problem only by scratch resistent laquer which is an expensive solution.. or by covering the car which is not practical

[omega3000]

Have thought of covering the car but then i think the cats would jump up in between the cover  Will try to remove scratches with paint cutter 

[cem_devecioglu]

Have thought of covering the car but then i think the cats would jump up in between the cover  Will try to remove scratches with paint cutter 

dont try to remove them completely..  an old paint wont have the same thickness with the new one
 
and stop every minute or less to check

[BazaJT]

A general rule I have found works well with scratches.If you lightly run your finger[or thumb] nail across a scratch and it snags an edge then it's too deep to do anything with but touch in/paint,however if your nail doesn't snag then you may be able to flat the scratch[I use 3000 grade wet or dry,used wet]and then polish up with G3 followed by G10 compounds and then polished with a general car polish.Trouble is my mig needs the paint option!!

[cem_devecioglu]

A general rule I have found works well with scratches.If you lightly run your finger[or thumb] nail across a scratch and it snags an edge then it's too deep to do anything with but touch in/paint,however if your nail doesn't snag then you may be able to flat the scratch[I use 3000 grade wet or dry,used wet]and then polish up with G3 followed by G10 compounds and then polished with a general car polish.Trouble is my mig needs the paint option!!

yep.. but you can also treat deep scratches by filling primer/base coat/laquer ..   although the treatment requires some time and money..

[feeutfo]

IME a scratch may well be too deep to remove completely by polishing, but polishing will take the edges off the scratch and make it much less visible if a soft polishing pad is used.

Good stuff cem. 

[cem_devecioglu]

IME a scratch may well be too deep to remove completely by polishing, but polishing will take the edges off the scratch and make it much less visible if a soft polishing pad is used.

Good stuff cem. 

thanks Chris

[cem_devecioglu]

and one more note: if you will try the hardest , to repair a scratch resistant laquer with the same kind, you are in trouble
 
it dries very late outside, so you definitely need a closed garage or else your car will stay with plastic glasses outside for more than a day for proper drying and you will eat your fingernails praying it doesnt rain

[cem_devecioglu]

now the final detail:

 
when you fill the scratch or stone chip with paint, you can sand it easily without any problem and get a smooth surface..
 
but when you apply laquer (clear coat) and fill the hole, inevitably you cant get a flat surface .. solution is of course sanding
but there is a small problem, laquer is much more resistent than the paint so you have to sand for longer period which is risky and you can easily bend the metal surface if you apply even a tiny force.. solution is to cover the area with some bondo as in figure (at least 4 cms wide both in left and right of repaired area .. so when you sand it you will distribute down force evenly and flat the surface without damaging the laquer.. 
 
ps: bondo must be not thicker than a mm ..

[cem_devecioglu]

now here are the results after repair (pictures taken with a 5 megapixel camera)
 
they are both paint filled and laquered ..
 

 

 

 

[cem_devecioglu]

ps: there is a blck dust on the camera in the upper right corner..  its not the stone chip..
 
pps: if you apply the paint and laquer with a sharp small spatula , you may get better results..