question for paint guru

[yeuporsch]

I am attempting to do paint a panel on the Porsche. I want to know how to color sand to get rid of orange peel look. What should I use? If I am painting part of the panel, do I have to paint the clear coat over the entire panel? How long should one wait after color sanding before one can do the clear coat?

Thanks,

John

[Porschekid962]

If the primer is sanded well the base should go on without the need to sand it before you shoot the clear. You can shoot the clear about 20 minutes after you shoot the base color, it dries very quickly. Do you have your compressor setup with a water trap so no water at all goes through the paint gun? You dont want fisheye. I found that when I blow clear at 85-90 psi it goes on smooth enough to where i dont need to sand and buff it afterwards. It was only a 5th scale model but i dont see why a full car would be any different.

[widebody911]

http://vintagebus.com/howto/colorsand/

The delay between base and clear depends on the paint system.

[fuelie600]

You have to paint the whole panel. If you are going to color sand the clear, you'll need 2-3 wet coats. With most good clears, 24 hours is ideal (at 70 degrees and above.) If you wait longer, the urethane gets very hard. It will take longer.

Also, most automotive clears want around 10 PSI at the paint gun cap on a HVLP gun.

Check out this site http://www.autobodystore.com/class.htm also the BBS on there. Good info.

Are you just repairing the existing clearcoat?

[jstobo]

From a body shop i use this is the sequence after painting(includes clear coat)

1- Wet sand with 2500 grit

2- buff with 3m compound.

3- buff again with 3m finessit

4-wax

No orange peel after this.

You really need a power buffer to do it. Hand buffing will wear you out.

[Mike Kast]

Originally posted by Porschekid962
It was only a 5th scale model but i dont see why a full car would be any different.

That is funny!

[na2ub]

I saved that link to read through later. Can anyone recommend a good paint / autobody book? My paint is cracking from age and UV exposure, under the clear coat, and especially around the edges of the panels, where it has actually started chipping off. I need to start reading if I plan to paint next spring / summer.

Thanks,
Doug

[Porschekid962]

Mike why is that so funny? Same principles apply to big and small when painting. One of the car models that I painted for a friend was very elaborate. Primer, white pearl base, metallic greay for the windows, then a funky custom color from house of color that looks kinda like olive drab, then draped cheesecloth over the whole thing and shot black. then i shot 6 coats of clear at around 90 psi. when you graduate art center the models are your life, they have to look damn good. paint jobs on them are usually ten times better than any car because they are smaller you see any flaw.

hey i dont mind, they pay me back with alcohol or other bribes.

[Mike Kast]

I wasn't sure if you were kidding or not. Sorry for the wise a$$ response. I couldn't begin to explain why it is different in an understandable manner. I'm not that good of a writer and I have limited paint experience. It is different though. On a large area the paint is drying before your complete. There is more skill involved in laying the paint on evenly. Metallic can look horrible if the overlaps are done incorrectly. On a little car there is hardly any overlap. Plus there is the wear and tear on the paint that a model doesn't see.
I hope some experienced painters can chime in here. I'd like to hear why myself. I love models too. by the way! It's pinewood derby season soon. Look what I've been working on. Don't thrash me too hard guys. It's not Cub Scouts. It's YMCA pinewood derby, Kindergarten division. I'm allowed! My daughter is the production manager and will help with the paint.



It isn't the greatest shape for speed but I'll see what I can get out of her