DIY TIP: Cleaning your Skunk2 Shift Knob and other aluminum parts
 

If you have a satin-finish black or dark-coloured aluminium part installed on your car, you've probably noticed that when you clean it it leaves an odd "rainbow" pattern. I found this to be particularly bad with the Skunk2 shift knobs. Here's a DIY to get rid of the rainbow effect and get it back to original condition.

Take a Kleenex and soak it with WD-40. Note that it shouldn't be dripping wet, just damp. Wipe down the knob, taking care not to over-do it on the top since WD-40 can soften or dissolve the paint on the shift pattern (1/2/3/4/5/R). Once it's coated pretty well, let it sit for about five minutes. Repeat the procedure, but this time wipe it down with a clean Kleenex about 30 seconds after you apply the second coat of WD-40. Once complete, the knob should have a uniform dark gunmetal look with no rainbow effects. Once you're done, the knob shouldn't be wet since you wiped it down with a clean Kleenex. So, it won't get all over your hands while you're driving.

This usually lasts a long time if you don't clean it with soap or windex. But, since your hand is in contact a lot with this, you may have to do this every once in a while.

Here's the technical explation of how this works, if you are interested.
Have you ever seen a small gasoline spill in a puddle and noticed a rainbow effect on the surface? The reason this happens is that the gasoline forms an extremely thin layer on top of the water. If you see a rainbow pattern on the puddle, the thickness of the gasoline/oil layer is roughly 400-700 nanometers thick. Visible light has a wavelength of ~400-700 nanometers. When white light hits the puddle, it is refracted by what is effectively a prism that is as thick as the wavelength of a particular colour. Since the thickness of the gasoline/oil layer is the same as the wavelength of light, it reflects back various colours of the rainbow.

So how does this apply to an anodized shift knob? I'm not 100% sure of this, but here's what I think is going on. When you wash the knob with soap or any other cleaning agent, it leaves a very thin residue no matter how much you rinse it off. The soap in effects binds with the anodized surface of the knob. Using WD-40 effectively dissolves the soap away and leaves you with a uniform WD-40 layer that is much thicker than 700 nanometers. This prevents the rainbow effect from occuring.

I got my Skunk2 yesterday (used) and it had this problem. I did my WD-40 trick and it worked beautifully. You can do this to other satin-finished aluminum parts, but keep in mind that if you wash it with soap, it'll clean off the WD-40 layer and the problem will return. I haven't done any long-term testing yet to see how long it lasts on a shift knob. My feeling is that since it's in contact with your hands, it may get wiped away over time.


Let me know if you try this or run into any problems!


ELaudio