Casio A158W is a classic digital watch whose design hasn't changed for the last 30 years. It’s crazy to think that a piece of technology can remain unchanged for such a long time especially since they are still making them. The rule “if it ain’t broke don’t fix it” certainly applies to the watch but that doesn’t stop me. Just cleaning up the cluttered watch face makes these look in my opinion so much better. And the inverted screen is just a cherry on top. I’m not the first person to figure this out. A lot of people have done this mod before. I’m just the first one to write down all the steps necessary. As far as I know at least. So let’s start.
- polarizing filter - I got iPhone one because it was easy to get
- Black spraypaint - RAL9005 in my case
- T7000 glue or any other glue
- masking tape
- isopropyl alcohol / rubbing alcohol
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Step 1: Disassembly
Start by removing the four screws on the back. The backplate also has an o-ring so make sure you don’t lose it when removing the backplate. The electronic comes out as one piece. The only thing keeping it in place is the tension on the buttons. You can just pry it out with a screwdriver.
Next, you can remove the acrylic watch face. It’s held in place with some double-sided tape. I first covered the font with some masking tape so it wouldn't get scratched as I’m handling it. Keep in mind that the tape is really strong and pushing it out took a lot of effort.
Step 2: Inverting the LCD Screen
This step is completely optional and I’m saying it because it has one big drawback. The visibility of the screen is a lot lower. It’s not really all that bad but I’d say the original was perfect and the inverted screen is just fine when it comes to visibility.
First of all, you need to take the LCD off. It’s only held in place with a plastic retainer. When removing it try not to lose the rubber connector for the LCD. Next, remove the polarizing filter. I started with an x-acto knife, getting it between the glass and the filter. Once enough of it was peeled I simply grabbed it and peeled the rest off. I then cleaned the glue residue with alcohol. As a new filter, I bought some filters for iPhones. One side had glue pre-applied which made things really simple. The only thing to look for is the orientation. I have put the screen back on the watch to see how I need to rotate the filter. Once I was happy with the orientation I stuck it on the screen and assembled the watch back together only to realize it doesn’t really work. The problem was I put the filter on the entire front glass. Which pushed the screen harder on the connector. Once I removed the filter from that part of the screen it worked perfectly.
Step 3: The Watch Face
To remove the adhesive I used WD40 to soften it first. Isopropyl alcohol might work as well. Then it was just a matter of scraping it off. I used a plastic phone pryer on both the watch face and the body of the watch. It worked surprisingly well. Next, I have soaked the watch face in alcohol to loosen up the original paint. To be completely honest, I don’t think it really did anything. Nonetheless, I took the phone pryer again and scraped the paint off which came off quite easily.
With the watch face cleaned I prepared it for painting. After several tries, I’ve made a template to position the cut-out for the screen precisely. You can download it below. It’s both a template for positioning the cut-out and the box to get the size right as well. I’ve printed it on a glossy paper, placed electrical tape over the template and cut it out. I have removed the paper and placed it on the watch face. The other side of the watch face was simply covered with masking tape. Using an electrical tape had its drawbacks. I’ve noticed it shrunk once the paint dried which wasn’t a problem for me but that doesn’t mean it won’t be a problem for you. Another thing I’ve noticed is that one of the edges has some glue residue from the tape but removing it would ruin the paint as well so I’ve just left it there. I’m guessing the glue residue actually appeared there due to the shrinkage. So please feel free to try some other tapes or methods.
Now to the painting itself. I’ve used glossy black paint (RAL9005) from a spray can. I ended up using just a single coat as the paint is well protected inside the watch. The biggest problem I had was that the paint started developing these gray spots as it was drying. You can see those in the video. I’m still not sure why but my best guess is that it was the high humidity in the room. In the end, I have just rubbed the grey spots with some isopropyl alcohol on a tissue and they disappeared.
Step 4: Assembly
I glued the watch face back in place with T7000 glue. This glue is usually used for putting phones back together so it works perfectly in this application. I’ve used a generous amount to make sure the watch will stay water-resistant. This lead to some squeeze-out around the edges which I found to be easiest to remove once the glue is all dried up. Of course, I encourage you to put the watch face back in any way you like. Any other glue or even double-sided tape will work.
Assembling the watch back together is, fortunately, the same process as taking it apart but backwards. Since you’ve already taken it apart I won’t really get into it.
Overall I’d say this project is quite simple and the effect is certainly noticeable. I’ve been wearing these for the last couple of weeks and I’ve gotten several compliments and some people were even wondering what they are. Others said they looked old school which I took as a compliment :)