Vectronics VEC-1500K - Manual (Page 41)

36
LESSON 9
Desoldering for Repair or Replacement
In addition to installing parts, it's helpful to know how to get them out! If you
work carefully and use the right techniques, parts may be substituted or replaced
with little or no damage to PC boards. Here are some common methods for
removing them:
Heat and Pull: This old standby method involves heating a connection on the
solder side of the board, and tugging the component free on the opposite side.
Because components are removed in "see-saw" fashion, this technique is usually
limited to parts with two leads. There's a fairly high risk of component damage
from lead stress, so use care when extracting parts you intend to recycle.
Heat and Brush: The "heat and brush" method is another older technique that
works best on single-sided boards where the pad surface is used for lead
retention. First, the connection is heated--then molten solder is swept off the pad
using a small stainless-steel wire brush. After sweeping, the bent-over
component lead can usually be pried up with a hobby knife and removed. "Heat
and brush" can get messy, since molten solder may fly onto nearby tracks and
pads. Always inspect the surrounding area for solder bridges and debris! Other
more contemporary methods may work better.
Solder Wick: Solder wick is a very handy soldering aid made from fine-mesh
copper braid. It is highly-solderable, and will tend to "draw up" molten solder
when applied to a heated connection. Wick is available in various widths from
electronic distributors, and some types are pre-fluxed to enhance performance.
To use wick, place it on the soldered surface and press down gently with a hot
iron. As solder melts beneath, it will flow into the copper mesh--up and away
from the contact surface on the pad. Wick is effective on flat surfaces and plate-
through eyelets alike! If a plate-through lacks sufficient surface solder to start
the wicking process, add a little more to the connection to "prime the pump".
After each application, nip off the solder-saturated end of the wick and start
over. Wick is a preferred method for desoldering both through-hole and SMD
boards.
Heat and Pull
Hemostat
or Pliers
Heat and Brush Solder Wick