The thumbpad on my Gamecube controller came off leaving a sharp plastic stick on which to give myself blisters. I've looked all over for replacement thumbpads, but they're no where to be found. I found a product called GelTabz at GameStop for about $5, but their pads didn't fit on my NGC controller's stub.
I decided to coat the stub in rubber myself, I Google'd for liquid rubber for a minute before remembering an Instructable called Rubber Origami by BlightDesign. That's where I got the idea to use Plasti Dip.
The 2 coats of Plasti Dip made playing with my Gamecube controller much more comfortable, but still a little irritating to my thumb after a bit too much play. I think I might try another coat or two in order to get more padding around the rim of the joystick since it's still a little sharp. I'll update this Instructable when I do, but it might be a while since I just moved and doing this on my couch and floor is a little bit of a hassle.
*Added 3 more coats, definitely a lot better. I wouldn't try doing 5 coats all at once, but maybe do 2, then do another 2 after 12 hours. 4 should be fine, I only did 3 more cause the first time was a little thin cause of the troubles I had.
CVS - or any drug store
Cotton Swabs - $3
Isopropyl Rubbing Alcohol - $2
Home Depot - or most hardware stores
Wire, 18 Gauge Aluminum - $3.50 (Optional)
Plasti Dip - $7.50
Please read the MSDS (Material Safety Data Sheet) for Plasti Dip. The fumes are a bit much so open a window and be careful of any sparks or open flames because it is flammable before it dries.
Step 1: Clean the Thumbpad and Everything Else
Use cotton swabs dipped in alcohol to scrub up any stains and the thumbpad area. You should use one hand to hold the joystick firmly all the way in one direction while you scrub away with the other. Sometimes the alcohol will break up what ever you're trying to clean, but will just push it around after, so you can use a dry cotton swab to pickup any wet debris.
Only a small amount of the alcohol is required, I usually just fill up the cap about 3/4 of the way and dip the swabs in there.
Step 2: Prepping the Drying Rack
I poked 4 holes into a cardboard box that my TV came in, threaded the aluminum wire through and tied it together on one side. Don't tie it too tightly or you will cut through the cardboard, just enough to make it a little tight.
Plasti-Dip is pretty thick, but there will probably be some dripping so don't let the controller dry over anything you want to keep.
Step 3: Prepping the Work Area
I cut the bottom off a Coke can for my container, since it was handy and disposable. There was some funky syrup stuff on the bottom that was a little hard to clean, but hot water + scrubbing + alcohol + more hot water = clean enough.
You're gonna want to cover the area you're working over with either paper towels or news papers. Also make sure to keep your paper towels, cotton swabs and alcohol handy.
Step 4: Dip It... CAREFULLY!
The instructions on the Plasti Dip suggest that you dip at a rate of 1" every 5 sec. We're only dipping a fraction of an inch, so I don't think the timing is too important. Just take it slow, especially when you're pulling it out.
You only want to dip enough to cover the top of the thumbpad and right under it, try to minimize how much gets on the shaft, but a little bit is OK.
Step 5: Let It Dry
The rubber should shrink as it dries, so if it looks like it has a weird bulge, just let it dry for the full 4 hours and it should go away. Once it dries it should be tight and smooth (although mine had an odd nipple in the center).
Step 6: Add More Coats
If you dip it too far, start cleaning immediately.
Between coats the top layer of the Plasti Dip in your dipping tray might solidify, you might be able to stop it if you stir every once in a while, but I just made a little hook out a bit of aluminum wire and pulled it off.
I'll grab a pic of that if I ever add another coat, but it didn't occur to me at the time to take one.
Step 7: Emergency Cleanup!
Then use the old trusty cotton swab dipped in alcohol to get up the remains on the bottom of the joystick near the gaps. Make sure to clean up what you can, then move the joystick in every direction so you can to clean up anything that started dripping. You can clean off the rim of the controller around the joystick next since you're probably gonna want to save the shaft for last.
Get a little bit of the shaft clean, but don't worry about it too much. What ever you can't get, just let dry and pick it off later.
Step 8: You're Done!
Congratulations! You just fixed your controller for about $16, which is a good deal if you have a couple controllers that need fix'n or if you have a Wavebird since they don't make them anymore and go for about $30 used on eBay.
You should also have plenty of supplies left over to repair any other controllers, which for me is probably 2 or 3 with the same affliction.
Step 9: Update!
I took the controller apart this time, as suggested by ZombyDude, because I had a better area to work in and I found my tri-wing screwdriver.
Here are a couple pics from the process. Definitely recommend this method if you have the right tools.