Even for bulk desoldering it pays to have a temperature controlled iron, avoids really bad oxidation when the iron is sitting idle and heating up WAY past usable limits, exposed to atmosphere at those kinds of high temperatures (idle a 40 watt iron without limit should hit 800F (425+C) with no air running across it) metals will oxidize rapidly, even stainless steel. Best case scenario is the iron over time will insulate better than it conducts and becomes useless as a soldering device. Worst case is it insulates well enough to set itself on fire.
Stupid user error (me) even cracked the ceramic element of my MPJA unit because I screwed the handle on too hard and the thermal expansion cracked the tip of the ceramic off (stripped the handle screw as well) I cheated a bit trying to postpone putting in the new element and used a tiny dab of heatsink paste to relink the broken tip and it's still holding on just fine. Wondering if I should try coating the entire element and inside iron with a thin layer of heat sink paste to increase the thermal bonding, give it a little expansion room etc... Anyone ever done that before to an iron? Ideally you want the heating element, temperature feedback and 'load device' AKA tip in the same package anyways, even thin layers of air (JUST like a CPU) will cause localized over/under heating, a thin layer of thermal paste seems natural to me? The MPJA units the ceramic is the heater/feedback connector, the failure point seems to me to be the ceramic to iron interface, I don't think simple physical pressure is enough, especially with ceramic (ungiving) to metal (ungiving)