Interior Painting

posted Jun 4, 2013, 6:57 PM by Andrew Stock
Progress report time! 

I spent a day or two this past week focused on painting, and was able to make some nice headway! I started by cleaning up the holes that I cut in the midplate from last time, which will allow the reservoir and pass-through fittings to go between the top area of the case and the bottom area. I just used some fine metal files, followed by some 600 grit sandpaper to smooth the edges:

Next, I wet-sanded down the midplate to clear up some of the cutting oil residue and whatnot, in preparation for giving it a re-coat of primer:

Double checked the cuts with the fittings to make sure they lined up the way I intended (you're looking at the underside of the midplate at the moment):

... and back in the booth for some more priming! 

While waiting for that coat of primer to dry, I went on to re-evaluate the coat on my case walls. There are some strange effects going on that are hard to capture... I think part of it is that the brushed aluminum pattern from the case wall is showing through the primer and paint, giving it a striped appearance that you can kind of see in the center of the picture here:

I re-sanded the pieces to try and get rid of some of the blotchy-ness from the first few coats that I think was ultimately due to being too stingy with the top coat, and I will be laying down another few layers of paint on these pieces to try and clean that up. 

In the meantime, the primer coats on the internal pieces completed drying, and I moved on to painting them as well. These pieces are what I refer to as "internal" parts, in that they are not visible from the outside of the case (for the most part) when it is completely assembled. For these pieces, I decided to paint them with a "flat black" paint from Duplicolor that ends up drying to look just barely not black... almost a really dark grey. Darker grey than MDPC Shade 19. The look is subtle, and I probably won't have the photography skills to capture the difference adequately... but it looks nice. 

Here's the radiators in the booth, getting their top coats:

The process I followed was to first put down a light dusting... just enough to cover the primer, but you can still see the primer through it. After 10-15 minutes, I would put down another coat moving in the opposite direction (so up/down if the last coat was left/right), this time with a bit more paint. Finally, I would lay down a third coat, this time with much more paint ensuring full coverage, but not so much that it pooled or ran or anything... just overlapping about 50% of the previous line to get a nice continuous coat. After the top coat dried (I gave these pieces over an hour, which is all the directions on the can recommended) I looked over the coats to make sure there weren't any defects, lightly clean off any dust that settled with a tack cloth, the put it back in the booth for the clear coat. 

To clear coat, instead of using spray cans, I ended up using a compressor and a spray gun. The primary reason being, I wanted to use a matte clear coat for these pieces to keep the matte appearance, and I couldn't find any good matte spray cans for Duplicolor paints. Fortunately, my dad had both a spray gun and a compressor to borrow... but the gun is old school, and I'm considering getting my own:

I also have my own compressor, but it's smaller and has a hard time keeping up with extended spray sessions, so I borrowed his (which is massive.) Only issue with this one is that the lowest pressure setting is 40 PSI, which is the maximum rated for the clear coat I'm using. 

For putting on the clear coat, I used 3 passes, much like the paint; the first coat was light, the second medium, and the third heavier with a 50% overlap. 

I noticed a little ways into laying down the first coat that for some reason, I was getting a lot of little white specks on the clear coat... it looked like residue from the gun or something. I cleaned the gun out well with water and dried it / ran it empty before putting in clear coat... my only thought was that maybe the pressure given by the compressor was too high:

I went ahead and switched it out for my compressor, but it didn't seem to make a lot of difference:

I wonder what's wrong? 

The only way I found to counter it really was to lightly rub it down with a tack cloth after waiting 10 minutes for each coat to dry... which got rid of most of the white dots, but a few still remained. I'm probably going to have to lightly wet-sand these coats to try and get rid of the dots, and see where I am from there. If I need to put another coat on, I will probably get my own HVLP air guns and try again. If it ends up looking good after a light wet-sanding though, I may just call it good.

Anyway, some of the pieces came out actually looking pretty good... others (like the motherboard tray and midplate) have a lot of white dots and will need to be redone I think. I took some pictures, regardless. 

Here's the midplate... you can see a few of the white specks. Granted, a motherboard will be obscuring the entire plate from corner to corner... so you wouldn't see it... but I'll probably still redo this one. I'm obsessive like that.  

Here's the hard drive holders... which really aren't hard drive holders anymore, as the whole area will be taken up by the reservoir. They're more of "structural integrity" pieces now.  I managed to clean up the white dots on them pretty well, so I think these are keepers. 

The radiators came out fairly nicely as well, so fortunately I won't have to redo them. They also will be mostly obscured by the radiator housing I built earlier on... all but the top edge, that shows "XSPC". Why did I go to all the trouble of painting them? Because! 

And finally, the midplate... which is too large for my ghetto little photo booth... so it gets a 'kitchen counter' picture instead. 

Next up... cleaning up the white speck issue somehow on these pieces, a few additional coats on the "exterior" pieces of the case, clear coats for them, and re-assembly! Until next time!