I have had many questions before of how to paint a case and all the different techniques you can use to do it so here is a tutorial i made for ya'll.
Step 1: You want to clean the case first (preferable a new one but nothign is worng with using an old case) They are easy to clean, you just want to get any dust, dirt, etc out of the case. I use Lysol Cleaning wipes. Soap and water is good too, just put some on a cloth and wipe down the case, inside and out. I will not be covering sanding a case in this tutorial.
Step 2: Picking your paint, I only use Duplicolor car paint for my cases, it is a very good paint. You want to use a metal paint which you can get at almost any autostore or even homedepot/lowes. There are 3 types of paint you need: Primer, the actuall color, and clear coat. Always stick with the same brand for all 3 to ensure they bond well.
Step 3: Apply the primer, now before you go Rambo and paint like theres no tomorrow, listen up. Use THIN, LIGHT COATS. I cannot stress that enough. If you do not, the paint will run and you will be kicking yourself later. You want to use a sweeping back and forth motion when spraying on the paint. The first coat of primer should barley cover up the exsisting color on the case. Wait 7-10 minutes between each coat of primer to ensure it bonds well. You want to be in a low humidity environment that is well ventelated such as a gerage with the doors open. Never paint outside as dirt will stick to the paint. I use 3-4 coats of primer untill the case is compleatly covered. It should take about 3-4 coats to do this. Now, you can wet sand between each coat of primer but thats only if you want a "showroom mirrior finnish" which I will not be covering in this post.
Step 4: Applying the color. This step is very simmiar to spet 3, except you are using color, not primer anymore. Wait 30 minutes between the last coat fo primer and the first coat of the color. So again THIN LIGHT COATS. Use the same sweeping motion you did before. The first coat should barley cover up the primer. Wait 7-10 minutes between each coat. It should take 3-4 coats to cover the case. If it takes more, thats fine but it should take a minium of 3, if it doesn't, then you applied the coats too thick, which is bad.
Step 5: Clear coat. This is probably the most important coat. Clear coat is essentually liquid plastic as i see it. It protects the color fomr fadding, chipping, etc. If you do not apply clear coat evenly, the color will not look uniform, hense the importance of clear coat. So once agian, 3-4 coats, sweeping motion, 7-10 minutes between each coat, you get the deal.
Step 6: Let it dry! Let case dry for 12 hrs after you finnish painting it. A low humidity environment is the best.
Step 7: Clean. Just wipe the case down again to remove anything that may have settled on it. Use the Lysol wipes or soap and water, what ever metls your butter!
YOUR DONE! congrats! If you followd my steps you won't have a problem, if you do, just PM me anytime. Good luck all!
-Mazy 
EDIT: one thing I obmited, do not paint when raining....please, I painted a case in my gerage while it was rainging once.....paint peels now. mazy=sad
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