Tires - Heat Gun or Grinding Wheel? Both?

[TQ97]

What's the advantages or disadvantages?  Obviously the heat gun cleans the tires off...but does it put another heat cycle in them as well?   What about grinding?   I saw that done at the indoor shows and then yesterday saw go karts use the grinder as well.   Thoughts? 

[goffin20]

I generally used a heat scraper to get off built up rubber and the grinder to scuff new tires.  After they have been raced, the grinder seems to just smear the rubber around and I prefer to remove the built up rubber.

[CrewChief6]

When grinding, what do you use? Flap disk? with what grit?

[goffin20]

scuffing new tires I use the flap disk with fine to medium, nothing to rough.