Rennlist - Porsche Discussion Forums

Rennlist - Porsche Discussion Forums (https://rennlist.com/forums/)
-   DIY - Boxster & Cayman DIY (https://rennlist.com/forums/diy-boxster-and-cayman-diy-138/)
-   -   Small Chip Paint Touchup Process...the post. (https://rennlist.com/forums/diy-boxster-and-cayman-diy/204072-small-chip-paint-touchup-process-the-post.html)

Rennen 05-14-2005 09:04 AM

Small Chip Paint Touchup Process...the post.
 
I made a post a couple of days ago talking about my paint touch-up process so I thought I'd make an instructional post about it in case anyone is interested. Just a cautionary note before I proceed. I've only made this really work well on single coat paint. I personally have found clear coat almost impossible to repair on a small scale. Also, please be patient when you are doing work on your paint! This is not a process you can hurry or shortcut.

Finally, I need to "disclaim" this process and just tell you that it has worked for me many times but I don't take any responsibility for your work on your car. Do not attempt this if you're not sure of your abilities. Seek professional help if necessary. This only works for small chips but does a really nice job when done properly.

Ok, here goes:

1. You must have the right products before you start. You will need:
  • A good quality car wash.
  • Paint cleaner (3M makes a good one) or a 50/50 alcohol & water mix.
  • Matching touch-up paint. I use paintscratch.com.
  • If you go down to bare metal, you will need to start with primer.
  • A dental probe or something like it
  • Sometimes, a small bit of 400 grit sandpaper
  • Toothpicks
  • Soft cotton rag(s)
  • Wet sanding, very fine sand paper or sanding block (Meguires makes a nice block you can buy at your auto parts store)
  • Polishing compound
  • Car polish (I use 3M Imperial Hand Glaze)
  • Clay bar
  • Your favorite car wax

2. To start, you should wash and dry your car so you're not grinding surface particles into your paint wherever you touch the car.

3. Next, you should put your car in a car port or garage to do the work. Set up some good illumination so you can see the area you're going to work on.

4. Clean the chip area using the paint cleaner or alcohol & water and a soft cotton rag.

5. Use the probe to feel around the edges of the chip. You need to make sure there are absolutely no loose edges to the paint chip. Use the probe to break out any loose edges. The cleaner the chip, the better the paint will bond even if the chip is larger than when you started.

6. Sometimes, you will need to do a little sanding in the chip to clean up the edges. I use a bit of 400 grit sandpaper cut out and glued to the end of a new pencil, eraser end. Use small, circular motions to do the cleaning. Remember, the purpose is to create a very clean area where the paint can adhere.

7. Clean the area again with the solution.

8. Assess whether the chip has gone down to bare metal or not. If it has you are going to have to start with primer.

9. I apply paint to the area almost exclusively with a toothpick. You are going to use the capilary action of the toothpick to "draw" the paint into the area you are fixing. You will need to use your judgement on the right amount of paint to leave on the toothpick based on the size of the area. I will tell you that the trick is to neither leave the area dry or to overwelm the area with paint.

10. Using the toothpick, apply enough paint to just cover/fill the chip with a slight outward bubble.

11. Let the paint dry completely and redo step 10 until you've created a rounded "outie" paint bubble over the area you're fixing. This is important! You must completely overfill the area you are fixing and it almost always takes multiple coats because of the drying reduction.

12. Once the chip is completely filled, you are ready to start the excess paint removal process. Be prepared to be a little bit distraught the first time you do this because the area is going to look messed up for a while and you might worry about it. Just trust me, it's not!

13. Lubricate the area you're getting ready to work on with a little undiluted car wash.

14. Using the wet sanding paper or sanding block, begin a small circular motion over the paint bubble. Be sure to use the smallest area of block or paper you can work with to do this. The goal here is to sand the paint bubble down until it is exactly even with the surface of the surrounding paint and go no further. Just repeat this process until you can't feel that bubble any more when you run your finger over the surface. BE PATIENT AND USE MINIMAL PRESSURE! The area on and around the chip is going to look very cloudy at this point. Never fear, you've only just started to make this look right. Next stop, polishing compound!

15. Next you are going to use some polishing compound and your soft rag. I just start working the polishing compound around and over the cloudy area using small circular movements. I do this repeatedly until I can't see improvements in the shine between applications. The area is going to start looking much more like it's old self with this work.

16. Next you're going to start working with the polish. This is important so don't skip this. I think this is really the step that brings the paint back into it's best look. Glaze basically is doing a micro cleaning/removal of the surface. You can use a random orbital polisher here if you're comfortable with that sort of thing. Otherwise, just polish by hand. I usually do at least two polishing to make the area all shine. Use your lighting and eyes to evaluate the need to continue to polish.

17. Next, I always hit the area with clay bar and soap/water to do final micro cleaning & polishing.

20. Wax & shine and you should barely be able to tell that you've fixed a paint chip there!

Good luck with this and let me know about your experiences. I'm sure there is room for improvement!

Computamedic 05-14-2005 09:45 AM

Red

Great write up. One small addition I would suggest is that your steps 12-14 (removing the "blob") can be made significantly easier by using Langka rather than wet & dry. Langka is a solvent which does not remove the original clear coat - no real benefit on single stage paint though. Details can be found here.

I would be tempted to use a finer grade of paper (1200 or so) and have found that clear coats can be successfully repaired by filling the scratch area with paint as you have described but instead of filling the area to a "blob", the barest minimum of paint is needed to colour the scratch and then fill to the "blob" stage with the clear coat instead. Then finish as you describe.

Regards


Dave

Rennen 05-14-2005 12:27 PM


Originally Posted by Computamedic
Red

Great write up. One small addition I would suggest is that your steps 12-14 (removing the "blob") can be made significantly easier by using Langka rather than wet & dry. Langka is a solvent which does not remove the original clear coat - no real benefit on single stage paint though. Details can be found here.

I would be tempted to use a finer grade of paper (1200 or so) and have found that clear coats can be successfully repaired by filling the scratch area with paint as you have described but instead of filling the area to a "blob", the barest minimum of paint is needed to colour the scratch and then fill to the "blob" stage with the clear coat instead. Then finish as you describe.

Regards


Dave

Yes, good points. I was suggesting the rough sand paper for the cleaning process. For wet sanding, you should use much finer auto finish paper as you've suggested. I have used Langka on clear coat and it does indeed do a pretty decent job.

One thing I forgot to mention is that you sometimes may need to thin the paint to get it to flow down the toothpick better than the straight paint.

Aronis 05-30-2021 08:07 PM

Step 0A. Go to Rennin's house and give him $150.00 and let him do it!

Very nice write up. You're an artist no doubt.

Mike



All times are GMT -3. The time now is 10:53 PM.


© 2024 MH Sub I, LLC dba Internet Brands