Scratches after cutting/buffing

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DWinTX

Member
I recently finished my first BC/CC paint job with 4 coats of UV clear. It went pretty well, and I'm happy with the results, but I'm struggling with the cutting and buffing. As you can see from the pics, I'm ending up with these scratches on some parts of the car. The odd thing, is some parts buff out real nice, but many have the scratches. It's a garage paint job so there is trash and orange peel. So here's my process:

  • Wet sand with 1000 till level. Sometimes I start with 1500 if the particular area isn't bad. If I start with 1000, I go to 1500 before the next step.
  • Wet sand with 2000, then 3000 and finally a 5000 Trizact pad.
  • Buff with rotary buffer. Have used both Chemical Guys Orange pad and Lake Country purple wool. Also have tried Meguiars 100 and Sonax Cutmax, both at the upper end of their suggested rpm ranges.

Lake Country advertised that their pad gets 1500 scratches out. But even in some sections where I start with 1500, I end up with scratches. What am I doing wrong?
 

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Megs M-100 and a wool pad will take out 1500 scratches fairly easily. You definitely have fine scratches left which is causing the reflections to be hazy looking.

Try the wool pad and M100 and work a 12" x 12" area with it. Start out with fairly slow rpms until you get the compound over the area you are working on then up the rpms to around 2000. Move from left to right with overlapping passes and then switch to up and down and the scratches should disappear. It should clear things up right away.
 
I'd say you have some 1000 grit scratches still there. Try what other said above. If that doesn't work, clean with W&G remover and resand with 1500. I'm in the middle of cutting an buffing a black car now done with Euro 2020. I'm using the LC purple wool/foam pad and JESCAR compound. This easily takes out 1500 grit scratches. I don't see any benefit to sanding above 2000 grit, IMO.
 
Are you sanding wet by hand? Make sure the surface, water and environment are clean. Scratches that won't come out are sometimes from grit under the paper. UV buffs easily, but it also scratches easily. It also sands and buffs better the longer it sits.
 
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I am wet sanding with a spray bottle, but I think I may have figured out my problem. The paper was dragging pretty hard, almost like it had a vacuum seal to the car. So I added a little soap and started spraying more water. I think I went a little too far with it and the finer grits were not getting to the surface. Like the block was hydroplaning on the car's surface. So the finer grits weren't taking out the previous grit's scratches.

I removed the soap, sprayed less water, and took my time a little more, and it seems to be doing much better. Another member told me via PM (accidentally, I think) that I may be using too much compound. That may have been part of it too.

Every step of this has been quite a learning experience. Now I know why you guys that do it for a living get the big bucks!
 
DWinTX said:
I am wet sanding with a spray bottle, but I think I may have figured out my problem. The paper was dragging pretty hard, almost like it had a vacuum seal to the car. So I added a little soap and started spraying more water. I think I went a little too far with it and the finer grits were not getting to the surface. Like the block was hydroplaning on the car's surface. So the finer grits weren't taking out the previous grit's scratches.

I removed the soap, sprayed less water, and took my time a little more, and it seems to be doing much better. Another member told me via PM (accidentally, I think) that I may be using too much compound. That may have been part of it too.

Every step of this has been quite a learning experience. Now I know why you guys that do it for a living get the big bucks!
Click to expand...
Im not a professional but everything i paint needs wetsand because i don't have a booth. A couple things I've learned in last 8yrs.

There is a difference in sand paper quality
Don't use a bucket.
Sand in a clean environment.
Don't have loud music. U need to hear the sand paper cutting and any high pitch squeek means u have contamination between the paper and the part.
It takes time. Especially if starting with 1000 grit.
Use wax and grease remover in-between rubbing compound and machine polish to show what u are working with
Clean clean clean environment can't be stressed enough.
 
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