It's a good idea of letting the shaft cool down before you fix the new front piece on it. I've seen a few years back a shaft kind of exploded because it was too hot after removing the old front piece + the heat of epoxy when a new piece was placed. It caused the carbon in the shaft to split and that shaft looked like a brush afterwards. I heard a bang from 20 meters away so you better let it cool down first... (ok it was cool
but a bit expensive and dangerous
)