Hey guys, I had a hood painted for my car by a friend and he does a great job but doesn't really think that paint needs wet sanding afterwards. Well, after he painted it I could tell that it needed wet sanding so bad to match the rest of my car. It had orange peel and little dust specs on it. Well, to make a long story short I wet sanded it with 2000 grit then followed that with a 2500. I started to polish those out with my 3m compound and my rotory with a white foam pad. I used about 1200 Rpms for the whole project and I am still not happy with the results. It left extreme burn marks in the paint that I got off with a porter cable, but I can still see some wet sanding marks in some places. My question is: What am I doing wrong and am I not using a good enough compound?
Wetsanding after fresh painting
- Thread starter LandonZ
- Start date
David Fermani
Forza Auto Salon
The 3M stuff is pretty strong and should be able to remove 1200 grit sand scratches. How long did the paint dry? Did your sandpaper possibly pick up dirt that deeply scratched the finish? You should try to perfect a small area to see what it takes to fix before doing the whole panel over.
xtremekustomz
New member
I waited about 3 days after paint before I started wet sanding. I am sure you know this but it is best if you sand in one direction. I used the 3M Perfect-It III Rubbing compound with the 3M compounding foam pad and them moved over to the Perfect-It III Machine glaze (05937) with the recommended 3M polishing pad. The only problem I had with it is that I had some holograms left behind after using the rotary. I just got the new PC out today and the holograms are coming out with no problem. I know that when I got through compounding I only had minor swirl marks and no sanding marks at all. Also I was using an air powered buffer so maybe you are compounding too fast. Maybe someone that is more experienced will be able to help you out a little more.
David Fermani
Forza Auto Salon
xtremekustomz said:
Actually the best way to sand is in a crosshatched pattern in the direction the paint was layed down.
Accumulator
Well-known member
LandonZ said:
You shouldn't be getting any "burn marks" at 1200 rpms.
There are a lot of different 3M compounds, but stuff like the PI-III RC 05933 and the PI-II FCRD (forget the number..maybe 39002) oughta take out 2500 marks pretty well and still leave a fairly nice finish requiring only a light follow up (as per xtremekustomz's experience, that's exactly the product combo I like to use) . That 05933 is still my all-time favorite product of this type.
But all 2500 paper isn't the same and paper like 3M can leave random scratches that're much coarser than the paper's rating. So yeah, you might have to repeat the compounding a few times. Get things basically perfect before switching to a milder product.
But use enough product and keep the machine moving. Don't overwork the compound. That mention of "burning" is, to me, pretty :soscared:
And as suggested, the pait might just need to cure some more. Sometimes it can be pretty surprising how much paint hardens up over the course of a few weeks.