De-soldering ICs
Use  a hot-air paint-stripper,1400W,500 degree centigrade,with 2 level heat 
control to prolong element  life. Activity may appear fearsome but it is no 
worse than a flow-solder bath.Pre-heat  for one minute  then apply to pcb,make 
extractor tool to pull ic from component side. Make an IC extractor from an old large pair,10 inch, of 
circlip pliers,the jaws need to open out enough to clip around the ends of up to 64 pin 
ICs with enough force to overcome the mechanical force of the situation where all 
the pins are angled relative to the PCB holes.Forge around both of the original circlip 
pins,one joggle at right angle to clear the heigth of the ICs and a slight inwards joggle 
to make purchase on the underside of the IC,grinding a wedge angle to the points 
helps particularly where there is no clearance between IC and pcb.
 [ Because of these joggles this tool is also useful for depressing the rear grippers 
and releasing of that type chassis mount fuseholders and switches when internally surrounded by other 
components ]
Use this technique for salvaging (working order) up to 64 pin ics ( when practised ),other 
components, sm and even repair (tracks are not dislodged).For repair work beware of 
spatter of molten solder causing solder bridges on adjascent compoents because if you 
are doing the job properly,ie not dislodging pcb tracks the IC must be pulled out with 
some force and the board tends to flex so possibility of flicking solder.
The secret is to be as quick as possible,idealy the body of the extracted ic will
be just about handleable rather than too hot to touch.Try practising on a board 
with close packed TTL chips or similar and aim for an extraction rate of 
something like one every 2 seconds.Between boards keep the hot air gun running on 
low power setting (not switching off).Don't rest the gun against the board when heating 
as vibration seems to affect the element life also don't allow the board to 
flex back onto the gun for the same reason.Hold the gun so airflow is angled to the board 
as solder spat directly into the nozzle can kill the element.
About the only components that cannot be removed with this technique are parts 
moulded in soft plastic,e.g. crystal sockets,rf coils with plastic former (IF coils usually OK) 
some DIP switches. Even these are desolderable intact if the body of the component is previously 
cooled with a blast of aerosol freezer spray.

SAFETY NOTE:- ensure good ventilation, use safety goggles because trapped 
water etc in the capaillary structure of glass fibre reinfiorced PCB can super- 
heat to steam and jet out molten solder,also it is possible to overlook small 
electrolytic capacitors on the solder side of the board which of coarse explode 
with the direct heat of the hot air gun and beware of very 
slight risk of combustion of adjascent flammable parts especially where 
components have extra (un-noticed) mechanical bonding leading to extended 
duration of heating activity.