The split rivets (chrome, not copper or brass) that you buy at the hardware store. You just put them in, seperate the ends with a flat head screwdriver, and you're good to go. If you want to flare the ends out 90 degrees, you can easily do that with needle nose pliers. I think they are better balanced and "dance" a little better when flared out 90 degrees as opposed to just flaring them out slightly. To remove, simply "un-flare" them and take them out. The rivet will be pretty much shot after that, but they are only about 20 cents a piece or so.
I agree wth drumaholic. Brass and copper rivets sound terrible. Very muted and choked sustain. Keep in mind that the longer and heavier the rivet and the larger the rivet head, the more pronounced the sound will be (and the the less sustain the rivet will have). Opposite, the shorter and lighter the rivet and smaller the head, the more subtle the sizzle will be (and the longer it will last).
I find the split rivets at my hardware store that are the same length and same head size as a Zildjian rivet. These work best. I had some rivets factory installed by Zildjian in a cymbal, and they didn't "dance" or last as long as I would have liked. I replaced them with these same split rivets, and although they are the same head size and length as the Zildjians, the split rivets "danced" better and lasted a bit longer.
I'm a total riveted cymbal geek ( I have 35+), so hit me up if you have any more questions. This is one topic that is defintley in my "wheel house".
