Hot melt works on carbons but I'm always very leary of heating the carbon shaft at all. I use a propane torch to heat the glue stick then apply the melted end to the insert. Once there is enough on the insert lightly heat the insert w/ glue on it just until the glue melts then insert it into the shaft, spinning it in as you go (it's easiest to do this with a point screwed into the insert). I have a small cup of water nearby that I immediately plunge the tip into to stop the carbon from getting hot. If I have to heat a tip to remove the insert, I put heat to the field point and pinch the shaft with my fingers as I'm heating so that I can feel if the carbon is getting hot (if you can't keep your fingers on it, I think it's too hot). It takes a while to do a dozen arrows like this so I usually only do it on my own arrows. For customers arrows, unless they request hot melt, I use a 15 minute epoxy (since I can't find 24 hr. anywhere and have to pay HazMat to get it shipped here). For any carbon shaft, the key to a good bond is making sure the shaft is clean. Oh, you can remove epoxied inserts with a bit of heat too, just be careful not to overheat them. Screw in a point and heat only the point while holding the shaft between your fingers just as for hotmelt. It helps if you've got someone to pull on the point until it comes out while you heat.