My quest for the elusive green volcano button begins with the ubiquitous Atari red. I've been searching for an economical replacement for the volcano switch without any luck. Therefore, my current approach is to build a switch from scratch. I started by trying to reproduce the button lens shown below.


I started by building a 2 piece silicone mold. The first attempt failed because when the inside of the lens fills with silicone, it acts like a syringe. The lens cap formed a strong vacuum which was doomed to air bubbles and breakage. I inverted the design and added vents in my design below.


Here is my first cast lens in standard Alumilite tan.


A perfect fit.


Now it's off to the local model train store to order the clear Alumilite and some green dye.


The clear Alumilite is much harder to work with than the regular. You are supposed to use a vacuum chamber and measure the amounts by mass instead of volume. Also the mold is supposed to be heated to 120 degrees. Seeing as I don't have a vacuum chamber or a precise scale, I just had to wing it. For the temperature, I just put the mold in the microwave for a few minutes. As you can see the first try did not turn out very well.


The hardest part is working with such small quantities. The Alumilte is expensive, so I try my best not to be wasteful. The lens cap only requires about 2 ML of resin. The smallest measuring cup I could find started at 2.5 ML. Furthermore, the dye can't be more that 5% of weight. The Alumilite resin consists of an A and B resin which you mix together and then must pour within about 90 seconds. I added the dye to the A resin using a toothpick. After several more tries I finally came up with a good mixture.


If you look very closely, you can see very tiny bubbles in the lens. This is the result of not using a vacuum chamber. I don't see any work around. I guess I might have to add a BYO vacuum chamber to my Projects List .


Unfortunately, my first success with the green was also the end of my mold. The clear is much more rigid and sticky than the regular Alumilite. This proved too much for the mold and the top piece ripped when I tried to remove it. If I make another try, I will probably buy Dow Corning's HS II silicone for my mold because it has higher tear strength.


It's too bad the mold died, because I wanted to try making a clear lens. I could then place an RGB LED in the switch so I could light it with my Rainbow LED Circuit



Here is a shot if the button illuminated on my Aluminum Flight CP. I used a super bright green LED which I chose because it gave a very emerald green glow. I had to dim the LED down with a 4700 ohm resistor because it was way too bright.