Watch out with using compressed gas duster (*not* canned air) on anything hot. It can decompose into pretty horrible compounds, among them (depending on duster type) phosgene gas and/or hydrogen fluoride. The current batch I've got is difluroethane and will decompose HF gas (which of course becomes hydrofluoric acid on dissolving in water, like in your lungs) if ignited or passed over a sufficiently hot surface.
Thanks, Jonathan On Thu, Jul 13, 2017 at 12:02 PM, jim stephens via cctalk < [email protected]> wrote: > > > On 7/13/2017 12:31 AM, Eric Smith via cctalk wrote: > >> There are also vacuum desoldering stations that use "shop air" to derive >> the vacuum, rather than having an internal pump. I've never used them as I >> don't normally have an air compressor anywhere near my electronics >> workbench. >> > This works very well. The best station for 7400 type IC's was a Weller > vacuum desoldering station. > > You had to have the full complement of accessories, and it was important > to have a dryer on the > air. There was a cleaning tool set which allowed you to service the tips, > and replacing them from > time to time was necessary. The technique of clipping off the IC didn't > work that well with this, > as the heat sinked into the chip as you desoldered. If you removed that, > you would potentially > delaminate the PC board, and in the days I used, it, the boards didn't > have that good of thru hole > plating. You could potentially pull the plating out of the hole if you > were not careful / lucky. > > I never had any boards with vias connecting to internal laminations, so > that never burned me, > but these days it's a different story. > > also being able to heat and apply air to the holes helped and that was > easy with shop air. Not > as good with canned air, if you use that to flush out holes after pulling > ic's > > I also have a plastic gizmo that provided vacuum from shop air, but it was > not near as good as > the Weller's integrated unit. > thanks > Jim >
