I must say this to protect my reputation. ;) I'd never in a million years do this now, with a heat gun or especially a torch. I did it when I was a broke kid and needed random TTL and SRAM chips to build stuff, and random unidentified boards full of chips were cheap at hamfests. :) -Dave On 4/17/21 1:04 PM, Chris Fala via vcf-midatlantic wrote:
I have only desoldered chips (very successfully) using a quality desoldering gun, but then I never salvaged from a scrap board, I only worked on boards that needed repair. I am not sure how I feel about the blowtorch method (I do think hot air has merit). Who out there thinks that a blowtorch used in this manner produces less thermal shock on the ICs than a desoldering gun working pin-by-pin?
On Sat, Apr 17, 2021 at 8:59 AM Bruce via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
I may actually have done this many years ago by the tedious method of soldering iron and SoldaPult, which works but is not to be recommended.
What I miss from this discussion is references to soldering coppers -- the original soldering/desoldering tool used by tinsmiths and possibly by plumbers, but which never seems to have penetrated the electronics field. You've all seen them at flea markets -- a sturdy rod of iron with a pointed chunk of copper on one end and a wooden handle on the other. I have a few kicking around. Now if you modified the shape of the working end, you could customize it to heat all the pins of an IC without heating the chip itself. The soldering copper itself is heated over a small burner -- a propane torch would do. Neat and efficient.
As to fumes -- a cardboard box at an open window with a fan pointing outwards makes a decent fume hood.
Bruce NJ
On Fri, Apr 16, 2021 at 11:23 PM Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
On 4/16/21 8:28 PM, Duane Craps via vcf-midatlantic wrote:
I remember reading a article many years ago, I think it was in BYTE, about salvaging IC's from discarded Printed Circuit Boards by using a chip puller and a torch on the back. Has anyone actually done this? I guess now you could try with a hot air gun?
I've done this, with both a blowtorch and a hot air gun. Both many years ago when I was a kid. I strongly recommend against the torch; lots of nasty fumes, and it's much easier to control the applied heat with an air gun.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Dave McGuire, AK4HZ New Kensington, PA