Water ^ Board wash ^ stiff/soft Brush^ deflux^ Windex^
Now a Tip on cleaning (standard disclaimer... use this info at you own risk. I am not responsible for
any problems or issues that arise form the use of this data. I provide it here because I have been
asked many times on how I do this.):
There are two sides to a board... the trace side (show in the picture) and the circuit side. These are
cleaned very differently.
Cleaning the circuit side...
Rule #1: Never use anything harsher then mild soap and water on the circuit side (I use Windex). If
you have something stubborn like oil, glue, etc... that needs removed, apply the solvent to a cotton
swab and apply only to the needed spots. Solvents can affect switches and other components (even
if they say "plastic safe").
Set board upright (vertical) on a towel (so the solution will run off). Spray the entire surface with
Windex and bush gently with a long bristled soft brush. Then rinse with clear water (spay bottle
works well). With a can of compressed air (I use a compressor set to 20psi) blow the surface dry.
Cleaning the trace side...
Rule #2: Don't over-do the chemicals. They are expensive and can affect the conformal coating.
Rule #3: Cover things in the area. Protect Items like other circuit boards, face plates, plastic dial
covers, knobs, etc... Over-spray and splatter from chemicals will mar surfaces.
Again, set the board up-right on a towel so the solutions will flow to the bottom (don't use one of your
wife's good towels!!!). Start with deflux. You can use the built in brush that some cans of deflux come
with or you can spray a small amount on a firm brush (such as a toothbrush). Scrub the board in a
general fashion (don't focus on a small isolated group of solder joints). This gives the deflux time to
work. Use only enough deflux to keep the board wet. Don't try to use the deflux as a wash/rinse. Try
to minimize the amount of chemical that "flows" to the towel. Work the deflux around for a few
minutes. If a section of the board begins to dry out, apply a bit more deflux to the brush and make a
pass over the section. After a few minutes you can focus on any stubborn spots (but keep the entire
Now before the deflux dries, you rinse the board. This is the tricky part and will make the difference
between a clean, shiny surface, and a mess. The object is to rinse the board with the commercial
wash and then (before it dries!!!) wash with Windex. You see.... the commercial wash is aggressive
and drys quickly. Don't let the wash stand on the surface or repeatedly spay the board. Given
enough time, it will raise and soften the conformal coating (and at $12-$20 a can. expensive). With
all that flux floating around the board, added to an aggressive solvent, you have a solution that can
make a mess of the board. Make several passes along the length the board with the wash, working
from the top down. Immediately, spray with the Windex.
Here is the secret... the solvents are lighter then water and will float on top. The Windex has just
enough soap to break the surface tension of the water. Surface tension is what makes water "bead
up". When you break this down, it will lay on the surface of the board and raise the solvent to the
top. It forms a nice safe barrier between the board and the solvents.
Use the Windex liberally. It will allow the flux and chemicals to flow off. You can gently scrub the
board with the soft brush. Then rinse with clear water and blow dry with compressed air. Touch up
the board (both sides) with a cotton swab with a bit of commercial board wash on it. If you are
cleaning a large board, clean one vertical section at a time (about four/five inches across), repeating
the whole process for each section..