Your thoughts on thermal conductive grease on hotend

I had to rebuild the hotend on my printer. I have seen some spirited discussions on using thermal conductive grease on hotends. What do you think?

I found it does make a difference between the heat sink and the heat break, but very few if any of the thermal greases can handle the temperature between the heat break and the heat block.

I’m confused, what possible benefit would there be to cool down the hot end more efficiently. Insulation would be best. Now, using anti-seize I understand and do, despite the smell for the first minute…

You want a sharp thermal break between the hot zone and the cold zone. So increasing thermal conductivity between the heat break and the heat sink means that that transition zone is shorter.

You don’t want an extended zone that’s not molten but not solid… in kind of a gooey state. That’s why cheap hot ends that can’t be machined well use Teflon in the heat break. Plastic that’s close to its glass transition temperature and then retracted into a cooler zone has a high tendency to stick to the side walls and create jams, specifically in PLA. Most other plastics are far more forgiving, like ABS I don’t think I’ve ever jammed it.

Oh, I misunderstood. I was thinking between the heater block and heat break. I see I didn’t read carefully. I get it now!