Ah, so *this* is why the YouTube views spiked-- linked back from Hackaday. ;-)
If you didn't read the YouTube comments or description I'll comment on a few things you all were wondering about.
* Pre-heating (either with the hot air on the back, or a hot plate) can help and is pretty much mandatory for multi-layer boards and RoHS solders (I generally never run in to through-hole DIP RoHS stuff though, YMMV).
* In the video, the board is actually sitting on a hot plate that is *off* (because my plastic camera tripod was sitting on it too). As the solder was blown out it was instantly re-freezing when it hit the thick steel plate-- that's why the grounds and some other pins didn't blow clean the first try (little solder stalactites heat sinking down to the plate). Also, the ground pads were close to the outer edge of the board where there's more convective cooling going on. Once I got the board elevated a bit more everything cleaned up with the air alone-- I didn't need to use any braid or anything before sticking in sockets and new DRAMs.
* I've been doing this since the mid 90's (originally to salvage parts on the cheap from surplus PCBs), so I'm sure I make it look easier than the first time you try-- use a scrap board! You *will* brown some (white) silkscreen and bubble soldermask and maybe delaminate some FR4 before you get good at it. With some practice though you just get to see the change in surface tension on the solder and know when it's good to pull.
* On my Hakko 850 I use the 0.25"/6mm tip for pressure to blow the holes clean. With the system set to '5' and '5' (basically half power on the blower and heater) that gives ~525°F/~274°C at the tip which is enough to flow old leaded solders nicely, but not so hot that you're burning everything else.
* You can adapt depending on what you're trying to do-- in the video I was most interested in not damaging the board (the DRAMs were junk), so I had things set low and slow. If I wanted the chips only and didn't care about the board I'd set the temperature higher and airflow *lower* to make the process go faster. If I burn the mask or silkscreen when all I want is the chip, it's no big deal.
* Doing bigger parts (40-64 pin DIP), you do need to be a little careful while removing them. The heat will soften the encapsulating epoxy and they can 'flex' a bit. I just slowly slide that wedge shaped tweezer I use in the video under the end of the IC once the solder is melted and gently push it farther and farther underneath as I heat the pins nearest to the fulcrum. It will gently lift the chip out without bending the package or the pins. For ceramics (they will crack before they bend) I repeat the process from end to end. (Don't try to pull a ceramic MC68000 from one end only if you want to be able to re-use it.) ;-)
* There can be a fair amount of splatter (kinda depends on how generous the OEM was with hole diameters and wave profile), so "maintain situational awareness"-- don't do it while wearing shorts. ;-) I usually just elevate the board a few inches above my bench and the solder loses some of its heat during the 'fall'. It'll still 'splatter', but only to the thickness of a few folds of aluminum foil and it's easy to just scrape off for cleanup. (Doing it over the cold surface of the steel hot plate also makes for easy clean-up.)
* You can also just pull all the parts in one quick pass (you basically draw the heat along and work a row at a time) and then go back and blow out the holes later. It's a little slower, but not by too much. Here's a much older video where I was doing that:
https://youtu.be/e_LlGOIDQwQ(Sorry, not sure how to embed video here.)
-Clay
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