Spot Paint Repair

Discussion in 'Body Restoration' started by Dueling73s, Sep 14, 2006.

  1. Dueling73s

    Dueling73s Veteran Member

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    Looking for some pointers from some experienced painters. I painted my car last weekend using PPG Base/Clearcoat system. After I already put on the clear, I noticed an area of appx 2-3 inches wides by 5-6 inches high where I sprayed the base metallic color too wet and the metallic is not uniform in this area as compared to the rest of the car. It is fairly discrete as you can only see it from one angle but it is at the quarter/roof seem and is very visible to me and I cant live with it. I want to wet sand the clear in this area and the surrounding area and shoot some color with some blending solvent then go over this area again with some clear with blending solvent. I have never done such a repair and dont know if my plan is valid. I could use some advise. I would really prefer not to have to totally re-do the roof and both quarters because of this small area. Any help or encouragement would be appreciated.
    Thanks
     
  2. Rick WI

    Rick WI Veteran Member

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    This is one of the hardest repairs in the business to make look right and it's also not recommended by any paint manufacturers. The BEST repair would be to wetsand the roof and quarters with 320 or 400, then dust in the repair area with base. No need for any blending solvent in the base. Just dust over the area that's mottled. Then reclear the whole area with two coats of clear.

    There is an upside to this as if you hard block the panels down the next coats of clear will really look nice.

    The problem with trying to blend in the clear into a small scuffed area around the damage is twofold. Number one is potential delam along the thin blend area. Then next issue comes in when you buff and it halo's. It's almost impossible to explain the feel when buffing along the blend line so that you don't cut into the clear and cause that problem.

    If you do decide to try the blend what I do is like I said, dust in the recoat on the base keeping a soft edge around the repair area. I then mix the clear in one gun and a hot reducer (blending solvent) in another gun. I wetcoat in the clear in the repair area then dust into the blend area. I wait for the clear to flash a few minutes then I dust in the blending solvent to melt the repair in. To much blending solvent and the repair will sag.

    I'd plan on about 2 to 3 hours for doing this. It's just a tough repair to get to look nice.
     
  3. Dueling73s

    Dueling73s Veteran Member

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    Thanks Rick,

    I think I will take your advice and dust the repair area with base and then re-clear the whole roof and quarters. Just re-clearing is still much easier than starting over and shooting with base again on the whole thing. Do I have a time limitation for re-paint over the sanded clear or can this be done any time. It is going to be awhile before my garage is free again to do this.
    Thanks for your help.
     
  4. Rick WI

    Rick WI Veteran Member

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    Once you block out the clear if you wait much more than a week I'd scuff it lightly with a green soft pad from 3M.
     
  5. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

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    It's been over 15 years since this thread started. Maybe spot repairs have advanced a bit since then?
     
  6. jthomas

    jthomas Veteran Member Lifetime Gold Member

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    I would say the procedure has improved since this thread started.

    I have had success with repairs like this. Here is the procedure I use:

    1. thoroughly wash the panel with water based cleaner and rinse thoroughly
    2. follow with wax and grease remover and allow to dry
    3. Sand area you want to repair and make appropriate repair.
    4. Clean again with wax and grease remover and tack off with a proper tack rag. Spray a sealer over repair area and allow to dry.
    5. Sand sealer coat with 1200-1500 grit just enough to feather the edge. As an alternative to 4 and 5 you can use a slow reducer to wet the edge where the sealer will be sprayed to melt the edge in. I prefer to just spray one coat of the sealer, let dry and sand.
    6. Sand ENTIRE panel with 1200-1500 grit. Use wax and grease remover again and then tack the panel with a proper tack rag.
    7. if you don’t have the original paint you will have to blend into the panels around the repair. If you have the original paint and the repair is recent to original paint job you can just do the single panel.
    8. Prep two spray guns. I use PPG. One gun with PPG color Basecoat mixed 1:1 with the appropriate HIGH TEMP reducer REGARDLESS OF THE TEMPERATURE, and the other gun with PPG DBC 500 clear base coat also mixed 1:1 with the same high temp reducer.
    9. Spray a medium wet coat of the DBC clear basecoat ONLY where the color coat will end. This is a wet bed so the color edge melts in. IMMEDIATELY spray the color on the repair area into the wet bed but not beyond it. This wet bed is especially important for metallics and pearls. Let it flash 3-5 minutes.
    10. Repeat the steps in #9 extending a few inches beyond the last spray. Flash again 3-5 minutes
    11. Repeat one more time, or if you got enough coverage from the second coat you can optionally mix the color half and half with the clear base coat and spray a final coat.
    12. If satisfied with repair, clean guns and then mix enough clear for 2-3 coats on the entire panel. 3 coats are best if you plan to sand to a show finish when done. Otherwise 2 is enough.

    Here is a repair I did on a 10 year old panel. I had fresh paint mixed but it was same paint type, code and revision so I took my chances. The paint was a metallic pearl. You cannot see the repair nor any difference between the newly painted fender and hood which was not blended into.

    11F6BFA0-3A68-422F-AC38-F789BF1F5D68.jpeg

    here is the blend zone. I marked the picture with black lines so you can see where the blend ended.

    0681756C-C881-470B-B4DF-DE6C85D479F5.jpeg
     
    Last edited: May 23, 2021
    Coadster32 likes this.
  7. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

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    Wow! Super work!

    Fancy a vacation to Florida? :)
     
  8. jthomas

    jthomas Veteran Member Lifetime Gold Member

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    I wondered if you had an issue with your paint. You have a great car from what I’ve seen on this forum. What’s the challenge you’ve got?
     
  9. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

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    This yellow spot behind the driver's side window.

    [​IMG]
     
  10. jthomas

    jthomas Veteran Member Lifetime Gold Member

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    I suspect you may have some metal oxidation or rust that formed under the leaded area that has discolored the paint.

    Regardless, that area unfortunately requires blending into the roof and upper part of the quarter and reclearing both quarters and the roof.

    Is this original paint? If so it is likely acrylic enamel and not base/clear. That means when you clear all that area it will stand out as a repair.

    Hate to say this but I would either live with it or do a full repaint.
     

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