As part of my YZ80 resto, I wanted to change the colour of the chain guide from a weird green and back to black. I thought I'd try dying it and it works!
Here's an extract from my blog (
http://glennsgarage.blogspot.com.au/) showing how to do it. Hopefully it helps someone out:
One part that has been bugging me for a while was the chain slider / guide that protects the swingarm. The one that was on the bike was well worn so I sourced a new old stock one. Problem is, instead of being a nice black plastic, it was an ugly army green!
Looking through my collection of photos of 1993 YZ80's showed that when they were brand new, like in the magazine tests etc, the chain guide was black. All of the second hand bikes show them in different shades of green. Strange. I can only assume that they loose (or gain!?) colour over time with UV exposure. Even though my new old stock replacement was still in the original packaging, it had turned 90% green.
Anyway, I wanted it to look new - black. I could have painted it but thought that was a bit dodgy. So, I thought I'd have a go at dying it.
I used some Rit fabric dye that I found on eBay. It comes in a little packet in powder form.
First step was to get a pot big enough to fit the part in, fill it with water and get it hot on the stove. I had it just below boiling and then added the dye powder. I wasn't sure how much to add so I just put the whole packet in and mixed it up.
Once it was mixed I backed off the temp so it was hot, but not bubbling at all.
Next, I used a zip tie to suspend the part in the dye so it wouldnt be resting on the bottom. I figured that if it was resting on the bottom it could potentially melt and it wouldn't get an even coverage of dye.
With the part hanging on a piece of timber and in the pot, I left it to cook for about an hour.
After about an hour, I took the part out, gave it a rinse in cold water and dried it off. Luckily, it worked! It looks like brand new black plastic again!