Help with painting

[Myrdhyn]

I just recently had an excuse (sold the psu right outta my computer) to rip all the stuff outta my computer, tear the case apart and start my first ever mod project. I will start posting the worklog shortly but I have a question first.

The inspiration for this mod came from the new optical mouse by razer. It has a chameleon paint on it green-purple changing. There is some easy to obtain (walmart) chameleon paint that is a three step process. Lay down the base coat which is a semi-flat black . Lay down the colour chameleon coat...basically a translucent paint with the chameleon powder in it. Then lay down the clear coat. Simple enough. I followed the directions to the letter as far as drying times etc etc. I went to sleep last night with it finished after two days of work...just had to let the clear coat dry/paint cure etc etc. It looked flawless I was so excited. I woke up this morning excited to see my finished case sides only to find a horrible sight. The paint as it dried pulled away from the edges of the case panels leaving a rough 1/8 inch space around the side looking stripped down to the base coat and in some spots the metal underneath. Even worse is the massive crack that developed from the middle of one side across the paint to the middle of another side all the way down through the color coat showing the black base coat underneath. Any ideas why this happened/how to prevent this?

I cant strip this down and start over b/c the paint is nearly 10 bux a can so I plan on putting some sorta border on it and coming up with some way (thinking silhouette of something ) to cover the crack. But mainly I want to know why this happened and how to prevent it in the future. Sorry for the encyclopedia of a post but I wanted to get a good description. I can post some pics when I get home from work.

[Crimson Sky]

Welcome to the forums!

How did you prep the case before painting?. This is a critical step and the first place to make a mistake or overlook something--did you lightly sand the factory finish? remove it completely? Give us the details of the prep and we can investigate from there

[Myrdhyn]

Well the case is the antec super lanboy if they gives you some info on what I was working with. The directions I had said sand with 400 grit sand paper IF it was bare metal, which it was not. It appears to be thin anodized aluminum with some sort of clear coat on top or something like that. I am not really sure. I basically just made sure it was clean and dust free and dry before I started since it didnt say to sand non-bare metal. Also it should be noted that the base coat stayed in place it is the color coat and clear coat that did not. I will go take some pics and post them shortly.

Edit: A friend pointed out that I should make it clear that it was NOT a primer that was used as the base coat. It was a semi-flat black paint. There were two main reasons for this 1. I couldnt find black primer 2. If primer were used it had to be black because the base coat is not a true base coat it is actually part of the "color" coat. If you spray the chameleon paint on say a white surface it doesnt work too well or even look the same. The manufacturer of the chameleon paint appears to sell what they call a semi-flat base coat (note not primer or paint so not sure what this means) so that may have been a factor.

[Myrdhyn]

Here is a picture of the crack and some of the pulled back edge. Sorry about the flash, I tried it with no flash and it just didnt work and the light in my apartment isnt the greatest for taking pictures. And the compression to get it down to size made it a bit blurry but you get the idea.

[Crimson Sky]

From what it looks like in the pic, the black base coat was not compatible with the chameleon paint. This is a common problem--mixing brands is a general no-no because they all use different solvents.

From my book:

"Knowing the properties of the paint your using is very important, and one slip-up can destroy hours of work by using the wrong combinations. Here’s the basics:


· Acrylic Paint Over:
Dried enamels, lacquers and other water based paint
· Acrylic Paint Under:
Enamels and water based paints

· Enamel Paint Over:
Acrylics, lacquers and water based paints
· Enamel Paint Under:
Acrylics, and water based paints

· Lacquer Paint Over:
Some enamel primers, other lacquers and unpainted surfaces
· Lacquer Paint Under:
Enamels, acrylics and water based paints

[Myrdhyn]

ok thanks Crimson. I'll start posting my work log with lots of pics as soon as I can sand it down and go buy more paint.

[slaveofconvention]

Make sure the paints you choose are of a similar nature. For example, the paint you are currently using appears to be a basecoat and lacquer - usually you would use a cellulose based primer for basecoat paints - 2k or 2-pack (where you have to mix the paint with a chemical hardener to make it dry) will almost certainly react with basecoats. Probably the easiest way to check is to ask what type of thinners you should use IF you wanted to thin the paint out - as long as the thinners match, chances are the paint won't react and you should be ok.

One other thing to bear in mind is that you will always get a better finish, both visually and in raw strength against damage, if you lightly sand every seperate layer of paint AFTER it has dried completely. For best results use wet'n'dry paper, and use it wet - you shouldnt be sanding anywhere near long enough to go through the paint, but it'll take out any imperfections leaving you with a nice clean surface to apply the next layer of paint to.

If you want a really high shine finish, add extra layers of lacquer - lacquer is little more than a clear paint so the more of it you use, the thicker the layer will become - this can result in a lovely deep shine to the paintwork as well as adding extra protection to the colour. If you scratch the actual paint on a chameleon colour it'll be virtually impossible to fix it up without completely restarting the job - if you scratch the lacquer, you can use wet'n'dry to polish out the scratch then add a couple more layers of lacquer to bring it back to a perfect finish.

There are no short cuts in painting worth taking - take your time, as much as it needs, and you'll end up with a fabulous finish

[Myrdhyn]

wow thanks for all the info, being a case mod noob (basically i know how to use tools and make canned spray paint look good most of the time but haven't tried it on a puter case till now) I need all the info I can get.

Well as it turns out its kinda a good thing this paint cracked and I have to strip it down. Because my girlfriend just bought me a neon martini glass for my apartment and I decided to strip it to pieces and use it in my case mod (I asked to make sure it wouldnt hurt any feelings). So I have to rethink my paint job completely. I'm currently thinking of doing a deep purple. But I imagine the process will be the same....base coat (primer right?) color coat, 2nd color coat, bagillion layers of clear coat, with wet sanding in between....now what grit sandpaper should I use when I wetsand inbetween layers...and should i sand on the every single coat even color coats or just on base and clear coats? or what? and when, if ever, will I need to use rubbing compound?

[crazybillybob]

I've been reading your posts and I don't think your issue is paint missmatch.
I maybe missreading this but didn't you say you used a Kit?

Also I saw you mention Anodized Aluminum...Well there is special prep for that!
Not pump another site but pimprig has a great tut on this Preping Anodized Aluminum cases Check it out his discription of the problems he had before he came up with this method or Spot-On for yours.

Good Luck!
Crazybillybob

[Myrdhyn]

it was sorta a kit....you didnt buy it together, you bought step 1, 2, 3 separately......what happened was my in my ignorance i bought steps 2 and 3 but for step one after doing as much reading as i could it appeared to just be a standard semi-flat black paint....so instead of paying 5 bux for a 6oz can of "step 1" i decided to save some cash and get the paint i was planning on using on the interior chassis (semi-flat black paint) and use it for the base coat since its both cheaper and comes in larger quantities....however i think the error was 2 fold.....the "base coat" was not black primer...just black paint...and also it was a different brand than the "step2 and step3".......

so i think that it was cause by both not using the correct paint (diff brands), my own ignorance, and not enough prep work.......also i dont know if i made it clear but im not SURE that its anodized alum. it APPEARS to be anodized aluminum with some sorta clear coat on top...best way i can describe it.....