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Help with sanding marks after buffing

Discussion in 'Wetsanding /Polishing / Detailing' started by jeepermat, Jul 30, 2017.

  1. jeepermat

    jeepermat Member

    This is my first cut/buff job, I've buffed countless scratches out of other finishes with great success, not sure what I am doing wrong on this.
    Car was painted with UV Clear about a month ago, I wetsanded the entire car with 1000, 1500, then 2000.
    I am using Chemical guys pads and compounds on a Porter Cable Random Orbital polisher.

    I started with their Orange Pad with V32, I did quite a few passes and still had sanding scratches. I suspected that I hadnt hit it with 2000 enough to get rid of the 1500 scratches so I really hit it hard with the 2000.
    Still have lots of scratches after polishing with V32, I did more passes stepping up to V34 and 36 without really eliminating any of the scratches. I am confident that the scratches are from the 2000, as they follow the direction that I sanded with the 2000.

    Ive done the same repair process on OEM finishes and have had no issues, this is the first UV clear I have done this way.

    Any tips for what I should be doing?
    [​IMG]
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  2. EddieF

    EddieF Top Banana

    Hope you put at least 3 coats of UV. You have lots more sanding to remove orange peel anyway.
    Looks like dirt scratched it or you rushed 1500 2000 and skipped 3000.
    I've only used a rotary. Get some fresh 2000 out & go over it all. Don't rush.
     
  3. jeepermat

    jeepermat Member

    There are 5 coats there, my eyes arent the best but I thought I got rid of all the peel at this point.
    Do I need to do 3000? It seems like everything Ive read here says to go to 2000 then buff?
    I thought I rushed the 2000 as well, so I went back and sanded quite a bit with the 2000 with no real change. I am 99% sure those scratches are 2000. I have been washing the paper off, and swapping to new paper pretty frequently.
     
  4. Jorge M.

    Jorge M. Member

    I hate to be that guy but........ You may have to grab a regular buffer (rotary) and a wool pad and go to town for the first cutting pass at least, and this is after more sanding you need to do. Looks like deep scratches from something you picked up while sanding.
     
  5. jeepermat

    jeepermat Member

    I am hesitant of wool pads because I am a relative newb to buffing and dont want to burn through. I may end up that route though.
    I am going to try resanding the car with 2000 and 3000 and a spray bottle rather than a bucket.
     
  6. Go back through the steps, as mentioned get some 3000 and 5000 (yes you need it) Trizact or equivalent and use them both. Being you are use a orbital you need to polish it out with the 3000 and 5000. The 3000 and 5000 will take all the scratches out (provided you sanded properly each step) and allow you to polish it with what you have. You'll have to work for a very long time to get 2000 scratches out with a orbital. Unless you are a complete Lump burn through is not an issue using a rotary buffer and foam pads. Keep the work area wet with a spray bottle and don't hammer an area. Keep it moving. Once you use a rotary you'll wonder why you didn't switch earlier.

    Oh and keep all your scratches going in one direction
     
  7. shine

    shine Member

    those ae 1000 scratches . this is why i do 1200-1500-2000 .
     
  8. Jim C

    Jim C Oldtimer

    yup, those are coarse scratches. you need to go back to the beginning and start again. 3000 wont take that out. if 1000 was where you started then you need to go back to 1500 and fully get those 1000 grit scratches out.
     
  9. crashtech

    crashtech Combo Man

    Buffing a color sanded finish with an orbital would be something I might wish on someone I didn't like.
     
    dhutton01 likes this.
  10. jeepermat

    jeepermat Member

    THanks for all the replys.
    I have ordered up a rotary buffer and 3M Perfect it compound and pads. Done with Chemical Guys after this, they recommended the Orbital over the Rotary.
    Also ordered some 3000 and 5000 grit.
     
  11. jlcustomz

    jlcustomz evil painter

    As far as wool vs foam pads, that can be considered a personal preference, but trying to bring up a shine after sanding with an orbital is just not a good choice for time vs result. Also consider that even an orbital can cause some burn through if improperly used. Any form of sanding & buffing on any material has to have proper progression in steps, other wise you're just wasting time polishing over the top of scratches.
    Contamination can come in all to easy from water & your sanding product. I think it was Shine that posted using a fuel filter in a small water line to flood wet sanding area with filtered water which sounds like an excellent idea to minimize contamination..

    It can be hard to tell from pics, but is there any chance those are sanding scratches from under the new paint where finish has shrunk into previous bodywork stage sanding scratches???
     
  12. shine

    shine Member

    oh yeah blame the compounds because you dont have a clue . you shortcut sanding and thought you would butt it out . those are 1000 grit scratches.
     
  13. EddieF

    EddieF Top Banana

    I tried the chem guys trial size 4 pack of compounds and wasn't impressed but some may love it.
    Scratches almost look like hard block used without rounded edges & didnt keep it flat.
    Always keep music & noise down when blocking to hear your work & keep it sterile. It happens though. My hood got a few.
     
  14. crashtech

    crashtech Combo Man

    I was thinking something like that myself, @EddieF . That or something got between the paper and the block. So many things can go wrong at that stage!
     
  15. Brad J.

    Brad J. Oldtimer

    That looks like dirt tracking to me. A piece of crap between the paper and finish that was dragged around. Usually you can feel or hear the sound of crap in the paper.

    It might also be the 1000 grit that didn't get sanded out. I'm with Shine on taking 1200/1500/2000 by hand over the 1000 and then I switch and do 3000 and 5000 trizact on the DA. I usually switch directions with each new grit and count 20 complete strokes and move over doing this continous for the entire job for consistency.

    Keep the chemical guys and use the rotary. The 3m won't help you because it's not a compound issue but a sanding issue. I use a known clean bucket with soapy water on a clean rubbermaid cart. If I drop a piece of paper it gets thrown away and the block washed in the sink.
     
    Bob Hollinshead and crashtech like this.
  16. killerbee812

    killerbee812 Newbie

    I agree I have a rotary (Makita) and a orbital (Torq), but using an orbital will take forever to remove sand scratches. I only use the orbital for polishing. Also am a big chemical guys endorser but the compound their compound is not aggressive enough to take out anything more then 3000 grit from experience only use it on polish jobs to remove swirl marks or bring back a luster. Get some 3M , Norton , or Meg. compound for rough sand scratches. 3000/4000 Trizact works good but to me for what it costs a more aggressive buffing method might work better on a budget.
     
  17. shine

    shine Member

    #32 and a white pad will cut pretty quick. if your not going to do the sanding steps get the marine boat compound . it cute really fast but money bet is your more likely to burn up paint buffing faster than polishing after sanding .
     
  18. JimKueneman

    JimKueneman Newbie

    Hi, my Coronet was my first paint and buff job. Before I got done I performed the Presta 2 step buff job 3 times. Each time I got more confidence in the wool pad and my ability. The first time I ran the buffer at no more than 2 out of 10. Second time 4 and the find time 6. I did not get scratches like that out until I had that confidence to really open her up. The high speed on the wool pad with the cutting compound made all the difference in the world.
     
  19. ExcellencePaint

    ExcellencePaint New Member

    Definitely go through your sanding steps again, turn that rotary up to about 2400 rpm with some ultra cut cream and a wool pad and watch the glamour happen.UV likes high speed cutting and medium speed polishing. Don't need a ton of pressure either, let the compound and the pad do the work.
     
    JimKueneman likes this.

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