I just sold off our PC board preheater, that's a thingy used to heat printed circuit boards from the bottom to make soldering QFN (Quat Flatpack No leads) packages on the top. In thinking about replacing it in our new shop a thought hit me, wife approves so it's not completely crazy.
Take the new hot air rework tool (miniature paint stripper with temperature control) and add a tube to the front with a 90 degree bend up. Mount in some sort of frame to hold the PC board over it and we have a new preheater. Best thing is the hot air gun will just pop off and be usable for normal rework without damage.
Anyway, no pictures since I haven't built it yet.
Here's a small preheater to show what I'm talking about. The temperatures marked are in C.