I glue most of my tips when they're slightly blunt. A couple of hours of play usually does it for me.
Sharp and hard tips kill the paint much faster.
I have been hunting around for the right glue for tipping, but i'm yet to find one.
Been using Selley's medium viscosity 4-pack tubes (ones that look like mini toothpaste tubs) for a bit, but once i open a tube, it's only good for one use (hardens up after some days), then i tried generic low viscosity ones. They can be used longer, but don't last on the spike as long as Selley's.
To [user]AlexSmith[/user], would you happen to know what glue Colin uses? I received a kendama from him sometime back and that stuff lasts really, really long.