Sorry mate. My point was given that you have done some work on the topic, I just wondered if working out ways to provide venting, is a waste of time or not. Everything I said was just guesswork.
Sorry on my part. I realized as I went to sleep that I probably
misunderstood you.
Yes, I think venting is probably not too useful. A main
consideration, I believe, is that most of the damage is being
done while the bike is stationary, in the garage (or somewhere
worse) overnight. Water vapor condenses out of the air inside the
dash as the temperature falls, forming droplets on the dash's
printed circuit board (PCB). The droplets pick up contaminants
from the board, and corrosion and another process that bridges
circuits begin.
In the garage, venting just serves to equilibrate the humidity
conditions inside and outside the dash. No useful evaporation
from air circulation would occur, I believe. When the bike is in
motion on the road a set of vents could be either helpful or not,
depending on the humidity, just like opening the windows in a
house is not always a good idea if the air is humid. I remind
myself that the outdoors, which is exceptionally well vented,
also exhibits dew drops in the morning.
Heated air could dry the dash out, but air entering again when
the bike is stationary and the heated air supply is presumably
turned off would continue to be a problem.
I now think of the dash as a little terrarium that I keep in the
garage. Inside it is air of unknown dampness. When I bring my
little terrarium out into the sunlight, especially on cool days,
the sun's rays pass through the transparent top, warm the
insides, and soon condensed water evaporates, rises as vapor, and
forms droplets that I see on the inside of the cooler, transparent
cover. I expect that many of us have seen this happen in our
dashes.
The problem is that the water forming those droplets has already
been doing its damage, working undisturbed in the little
terrarium over night, and over the winter, unseen and
unrelenting. Venting won't stop that, since the humidity of the
outside environment is not always low.
I believe the two solutions that I did implement on my bike can
both be effective. The first is a desiccant chamber that the air
entering the dash (for the use of the on-dash air pressure
sensor) has to pass through, and that is used to dehydrate the
air in the dash enclosure by flushing with an aquarium pump, the
whole setup taking advantage of some mysterious half-finished
tubing provisions in the dash mounting as it was delivered from
the factory. The second solution is a conformal coating I applied
to both sides of the PCB, carefully avoiding covering up the air
pressure sensor and other sensitive things like electrical
connectors.
The first solution has been only marginally effective, probably
because remembering to check the desiccant for the change in
color that indicates discharge, and to flush the system with the
pump, is something I'm not good at. To be really effective, I
believe I'd have to continue flushing and desiccant maintenance
through the winter. At any rate, I have seen moisture on the
inside of dash reappear on two sunny, cool days since I installed
the system.
I believe the second solution, the conformal coating, actually
works, even though moisture continues to enter and condense on
the coated board in spite of system number one. Its operation is
fascinating to me because it does not rely on stopping water
molecules from getting to the PCB. Being merely a plastic
coating, water molecules readily permeate it, moving though the
spaces between the molecular polymer strands. But, properly
applied, the coating adheres tightly to the surface of the PCB,
preventing water molecules from collecting together into
conductive droplets once they reach the board.
I expect I may get around to wiring the aquarium pump into the
motorcycle's harness so that it is always on when the bike is
running, but that really won't be enough because of the long
downtimes in the winter and overnight. If I were even more
obsessive than I am, I could wire the pump to run forever (just
like it is used to supply air to fish tanks), but it seems likely
that the conformal coating is a sufficient solution.
Moto
P.S. I saw that my lines of text were really long before they wrapped,
so I shortened them in an editor. I don't know why the problem happened.
Anyone know how to fix this?
P.P.S. Huzo, rereading your original posts, I see that you have thought
about some of the venting issues I just wrote about.