Hello everyone! Do you remember my last article about the Olivetti? One of the most important parts of the restoration process was the case colour. Today I wanted to explain to you how to deal with yellowed plastics; the different methods and some advices. So... Let's go!
Method 1:
Method 1: This method is the one I have used on my old computers. It actually works but be aware; this can be dangerous for your plastic parts if they do not have any "texture". Plain plastic can be easily be ruined. What I mean by "ruined"? Your case will not explode, do not worry. Your case will just end up with lots of spots and probably you will not like the final result. There are some solutions to avoid this problem but, first of all, let's see what we need!
What do you need?
Hydrogen Peroxide cream 40 vol.
Kitchen plastic wrap
Painting brush
Sunlight or UV light
What to do?
What to do?
The first step is to clean your case. Use water, soap, and anything you want. A good piece of advice is to use baking soda on black marks that don't want to come off. This part is very important so: switch on the radio on your favourite channel, dance to the music and clean your computer. ;)
Then, when your case is dry and free from glue, marks, and sticker you are ready to "paint" it. You have to put some plastic wrap underneath your pc. But not just some, you need enough to cover the entire plastic section. After that, open your hydrogen peroxide bottle and drop some of it on your case. Then, with your brush you have to cover the entire case in hydrogen peroxide cream. When you are ready you can fold the plastic wrap over the case. Then remember to "massage" the plastic wrap in order to remove every air bubble and to get the same quantity of cream all over the computer.
For the next step, find a spot where the sun is hot and leave there your computer; otherwise, you can use a UV lamp to get the same effect. The only important thing you have to remember is to rotate your plastic pieces every 10~20 minutes (especially if you are working on bigger pieces of cases [for example a CRT monitor]) because you need the sun to hit every side of your piece. Also, remember to "massage" them because other air bubbles may come out.
After a couple of hours (depending on the yellowing quantity) of rotating and massaging the pieces, you can remove the plastic wrap and clean everything with some water. Then ask yourself "Am I happy with the final result?" If you can still see some yellow spots, just put your pieces again to the sun; otherwise, you are ready to show them to your friends!
Some notes:
Please, if you want to use this method, be careful with keyboards and parts that have something written on. My commodore 64's keyboard's keys got discoloured after I tried this method on them. So if you can, use the second method for this kind of parts.
Method 2:
This second method is better for other kinds of plastic like some cases cases, as I said before, do not have a texture and are smooth. Also this is better for cleaning yellowed keyboard keys. But what is the difference between the first method and this? Let's check it out! ;)
What do you need?
Hydrogen Peroxide 40 vol. (Liquid)
Water
A plastic container
Sunlight or UV light
What to do?
For this method, you do not need to get your hands dirty with any kind of cream. First of all, like for the first method you have to clean your case with water and soap. Then, you will need your plastic container. What next? You should fill it with water (not completely, just put the quantity you need) and then add some hydrogen peroxide. After that, you should submerge your pieces there. If they start to float you can put something to stuck them underwater (do not put anything ON them otherwise the object you use will leave a spot). Now, just relax, you do not have to rotate anything. Just wait 1~2 hours (depending on the yellowing quantity) and when you think you are ready to go, just wash your pieces with fresh water. Easy, isn't it?
Some notes:
Your first question about this method might be: "How much water and hydrogen peroxide should I use?" So,talking about water you need enough to submerge the entire piece you are going to clean. The hydrogen peroxide does not follow any formula. Just add it in relation of the water. In other words, if you used just one glass of water, do not pour the entire bottle of hydrogen peroxide.