how to get a smooth surface?

What is everyone using to get a nice smooth surface after sanding on my first project i had tons of little scratches and dips,, what can i use to get these out?? thanks

Dips you would use bondo, just load it on and let it dry totally then go in with about 40-60 grit. After you have sanded the whole box with about 80 grit pretty well go to about 150. Sand it down real well to get all the scratches from 80 grit paper to 150 grit paper. Then go to 300. After you have sanded with the 300 pretty well prime the whole thing. Put on about 2-3 layers. Let it completely dry then wetsand it with the 400 grit. Prime again and then wetsand with about some 600 grit. Then you can wetsand again with maby 1000 if you want. I would suggest it. Then it is ready for paint.dream it, build it, fiberglass it

Sand, bondo,sand, bondo, sand, bondo and sand some more. attention to detail and dillegence is the only way to get perfect.

Ya i used bondo and did alot of sanding. Guess i just need to do more sanding. Well see how my next project turns out.

I'm not shure what your project is, but I generally use glazing putty, see link below. Glazing putty Stormshadow

The reason you go so in depth with using the right grit sand papers is because every scratch WILL show up when u paint it. If you applying vinyl its much less sandingdream it, build it, fiberglass it

After you use your Grinder or Air Angle sander, I suggest using Rol-loc pads with a baseless mandrel....(makes it alot more flexible and sands more evenly.  They are a 3m product.  They are green in color...you can get them in different grits.  After you then hand sand and get it down to a respectable smoothness.....fill the big pits with your finishing filler, go and find yourself a polyester high build primer  from napa or an auto paint store...the napa number is  "5190"....to spray it through a gun or for smaller jobs you can get an aerosol can with a refilable glass jar....  It sands really well and it gives you that finished sprayed on finish...you can thin it out with acetone. Sand that one more time till your happy with it....guide coat it with another thinner primer and paint it up.  Good luck!

The aerosol can with refillable galss jar is at NAPA as well?

Yes Sir!