Just be careful around cerroblend. According to Wikipedia... "... is a metal alloy that is useful for soldering and making custom metal parts, but which is toxic to touch or breathe vapors from." "...is toxic because it contains lead and cadmium, and contamination of bare skin is considered harmful. Vapour from cadmium-containing alloys is also known to pose a danger to humans. Cadmium poisoning carries the risk of cancer, anosmia (loss of sense of smell), and damage to the liver, kidneys, nerves, bones, and respiratory system. Field's metal is a non-toxic alternative. The dust may form flammable mixtures with air."
73 Eugene W2HX Subscribe to my Youtube Channel: https://www.youtube.com/c/w2hx-channel/videos -----Original Message----- From: cctalk <cctalk-boun...@classiccmp.org> On Behalf Of Chuck Guzis via cctalk Sent: Friday, April 15, 2022 7:42 PM To: Fred Cisin via cctalk <cctalk@classiccmp.org> Subject: Re: Advice on Desoldering an IC For very-difficult de-soldering, I use a variation on the Chip-Quik idea. I take a hunk of Cerrobend 158 fusible alloy and a file and make a small pile of powder from it. I then pack the powder around the pins of the IC to remove and heat the area using the light from a 75 watt PAR-38 halogen reflector lamp. (apply from the reverse side of the PCB). In very little time, the area of the board heats up enough to melt the cerrobend and it fuses with the solder. The part can then be easily removed (SMT stuff just slides off). Since the board never even gets to 100C, everything else stays in place and you don't burn the board or lift traces. Clean up with a toothbrush. Discard the fused metal. I suppose that instead of the lamp, you could use a hot-air rework tool set low. Anyway, that's what I do. --Chuck
