Beginner that needs help and confidence.

I am a complete beginner and bought my S2000 model exactly a year ago but didnt finish the model because I was to scared to do the body of the car. I now want to complete it but my main problem is with sanding. I have read all of the threads and guides from the likes of Primeraman on preparing/sanding the car before applying primer and have a few of questions which i need answering.

1) How do i know when I have sanded the car enough ready for priming, what will it look like and feel ?
2) Which direction should i be sanding in. In a circular motion, or up and down?
3) What is the difference between sand paper, grit paper, wet and dry sand paper and which coarse should I use if I had all of them available.

Help from you guys would be much appreciated.
thanks

From what I understand, you need to sand just to give the primer something to "grip" to. A nice run over the body in any direction should do the trick. Too much sanding will cause a flaw in the body and make it look obscure. If there are mold lines, lines where the body pieces where put together, those need to be sanded down flush with the body.

Also, from what I understand from which my dad told me, the coarser the grit, the rougher the sand. This is good for sanding down excess putty. A fine grit will smooth out and help with any imperfections.

Once again, this is only what I understand and I could be wrong.

well for starters welcome to AF. if you are scared to do the s2000 pick up a cheap revell or amt to practice on. as for the body. it depends on the paint and primer you are using. if you are using duplicolor primer, i would not sand the body, for the simple fact that the duplicolor shows EVERYTHING as it sort of etches the plastic. you always want to use wet sand paper. it keeps the paper from clogging and keeps it from heating us as much. as for grit. use 800 for body work and 1500 and 2000 for polishing

Sanding before priming is not something to worry about. The point is to remove all of the molding seam lines, and give a little bit of tooth for the paint/primer to stick to. A very fine grade, like 600 grit, will do great. When you're done, the shineyness of the bare plastic should be gone, but you don't need to sand more agressively than that. Doesn't matter the direction you sand. Sand paper and grit paper are the same thing, wet sand paper is sandpaper that's been dipped in water, dry sandpaper is paper that hasn't.

Welcome to AF!

Welcome to AF! The higher the gtir sandpaper, the finer it is. The grit is measured by how many sand particles per square inch there are. I was tought to sand with the body lines. Circular motion is ok too. Good luck with your S2K.

Frank X.

has anybody ever posted a picture of how a sanded car will look like?
and by the way how many coats of halfords white primer should i spray on after the sanding is done?

all you guys help is much appreciated.

edit: sorry i don't think i personally have any pics of the body after sanding, but i'm not sure about everyone else. you should wash the body, give it a brush to clean off any excess dust from sanding, let it dry, give it one last brush to clean off any dust that settled during the drying, and then spray on some primer. not all primer is compatible with certain paints, so if you're not sure about the primer/paint you plan on spraying with be sure to either make a search or to ask us.

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haha yea... i was scared to do my first body, too, but after i did it i realized it wasn't too hard. i mean i didn't do so great on it but it looked decent for a first paint job. when i did my first paint job i kinda just rubbed the sand paper all around till it looked good. i personally use lower grit sandpaper cuz i can't find any high grit, but i wouldn't recommend anything under 400 for prepping a car for paing. if you use the lower grit sandpaper make sure you don't push down too hard or you'll get deep scratches that you hope the paint will cover, but usually won't. haha. i've experienced it. anyways... good luck with your first paint job!

3) What is the difference between sand paper, grit paper, wet and dry sand paper and which coarse should I use if I had all of them available.

Help from you guys would be much appreciated.
thanks


Sand paper and grit paper are the same thing and its usually a light brown or yellow. Wet and Dry is the dark grey stuff you can get at Halfords or Wilko's. Instead of paper its made from a waterproof backing so it doesn't fall apart when its dipped in water. Dipping it in water stops the paint dust flying everywhere.

For fine sanding I recommend 1200 grit Wet and Dry and maybe 800 for coarser sanding.

Heres a more detailed explanation

http://www.diydata.com/tool/abrasives/sandpaper.htm

Cheers

Farrokh

I did post these pictures before, but I couldn't find it, so here they are again. I don't remember what I wrote before either, so there could be some inconsistencies with the previous post.

Anyway, here's notorious orange peel after applying spray paint. I applied 5-6 coats of Tamiya gloss black, with each layer was sprayed extremely lightly to avoid loosing details.
http://files.automotiveforums.com/gallery/watermark.php?file=502/2825p8250104m.jpg

Then, I used a small piece of Tamiya finishing paper 2000 grit to sand the surface in back-and-forth motion. At first, the surface turns mostly hazy, but there remain some dimples. And that show exactly how much more you need to sand. When the dimples are gone, the surface is smooth.
http://files.automotiveforums.com/gallery/watermark.php?file=502/2825p8250105m.jpg

Next, I used Detail Master's polishing abrasives and wet-sanded the surface with 4000 grit up to 12000 grit. (personally, 3200 and 3600 seem redundant after Tamiya's 2000 grit)
http://files.automotiveforums.com/gallery/watermark.php?file=502/2825p8250106m.jpg

Finally, I used Meguiar's scratch remover and Tamiya's rubbing compound to get this smooth and shiny surface.
http://files.automotiveforums.com/gallery/watermark.php?file=502/2825p8250107m.jpg

Keys to this technique are to apply sufficient paint, so that you don't sand all the way to the primer. And also avoid sanding corners and edges, because paint layer tends to be thin in those areas.

Check Alex's 550GT. He masked those areas to avoid sanding through.
http://www.italianhorses.net/Gallery/Resin/CS550Mil/550m.htm

Good luck.