Advice on sanding, buffing.... etc

[ca180]

Anybody have a site I could go to so I can check out paint prep. I seem to have a problem with sanding the surface correctly. What I mean is, when I primer an object (car panel), I sand it for color but I always feel like I'm using the wrong grit. Then when I lay the color I sand it for clear, and I still feel a little off. So the end product looks like crap. Lots of scuff marks. And hazy clear. If anyone has a step by step process they use for prep, between coats, and finish... please let me know, thanks a bunch.

Also to clarify, I'm mostly doing automotive painting.

[yoda]

After I primer I wetsand with 600-800 wet/dry sandpaper to prepare the surface for the mechanical bond with the base coat.

After my clear has cured I wetsand first with 1500 grit set/dry sandpaper and then follow up with 2000 grit wet/dry sandpaper and then I use a 2 part process to buff out the clear to a mirror sheen...

[yoda]

I was just re-reading your post and I have a couple of questions...what type of paint are you using because with most of todays basecoats you should not be sanding it! After you lay down the basecoat you should let it flash off and lay down at least one coat of clear before the basecoat dries to get a CHEMICAL bond between your base and the clear, generally approx 10 minutes....you shouldn't wait for the basecoat to dry and wet sand it...This may be your problem unless you are using a 1 part paint.....2-3 part paints should have all the coats sprayed allowing for flash time between coats and you don't wetsand until at least after one coat of clear.

I usually shoot 3 coats of clear, allowing for the flash time and will only shoot one coat of clear and wait until I can wet sand only if a foreign object...dust spec...gets on that coat and I don't want to seal it in with another coat.....hope this helps...

Hazy clear can be several things....One mistake I made early in my learning curve was to wax/seal my clear prematurely....You have to remember that you have chemicals burning off of the project for quite awhile and if you seal it too soon you trap those chemicals and they will haze your clear. I have heard many different theory's about how long you should wait before you wax the project and I don't really know the proper answer...I waited 90 days before I waxed my bike but I painted it in the winter and had time before I was submitting it to the elements...I believe most body shops tell you to wait 30 days.....good luck with your projects in the future....