Protecting Electronics from the Elements

[Z.O.R.G.]

I reached my limit on replacing trail cameras several years ago.  It didn't seem to matter if I bought a expensive one or cheap one - they all failed within 2 years.  When opened them up, I always found corrosion on the circuit boards either from moisture making its way in or batteries that leaked.  I came upon a simple solution...

Clear nail polish and RTV.  

I bought the cheapest camera I could find, took it apart and painted the circuit board with clear nail polish.  Being careful to brush it on evenly, get all arounds components and no to get it in connectors.  Then I RTV'd all the holes between the battery compartment and the electronics.  Every camera I've done this too is still operational.  

[majorhavoc]

That's a great tip.

[EBuff75]

Before it became more common for cell phones to be water resistant, I remember seeing articles about companies who would open up phones for customers and treat all the electronics in them with hydrophobic coatings.  IIRC it cost several hundred dollars, but they seemed to have a fairly steady business of butterfingered people who were willing to spend it as protection against their own nature!

[NT2C]

I reached my limit on replacing trail cameras several years ago.  It didn't seem to matter if I bought a expensive one or cheap one - they all failed within 2 years.  When opened them up, I always found corrosion on the circuit boards either from moisture making its way in or batteries that leaked.  I came upon a simple solution...

Clear nail polish and RTV. 

I bought the cheapest camera I could find, took it apart and painted the circuit board with clear nail polish.  Being careful to brush it on evenly, get all arounds components and no to get it in connectors.  Then I RTV'd all the holes between the battery compartment and the electronics.  Every camera I've done this too is still operational. 

Back in the days when I was a tech in the "coin-operated amusement and vending devices" industry (my first full-time job after getting off active duty in '76 - other than the family construction biz) when we had stuff that was supposed to be "weather resistant" we'd mask the connections then spray the boards with clear polyurethane.  Connectors got slathered with dielectric grease and, where possible, gaskets were also slathered with the same grease.  (We used to get the stuff in 2lb. industrial tubs)

It worked for the majority of the stuff we wanted to protect, especially in bars where it was not uncommon for equipment to get a drink or two poured on it or in it.  (Drunk guy tries to put his mug of beer on top of the Pac-Man game while he tries to dig out a quarter, it slides down the sloped case and dumps right in the air vents on top. Not much we could do to protect the monitor, but the boards and power supply in the bottom of the case usually survived.  Same with stuff like jukeboxes that often had drinks spilled on the selection buttons.)

[tirls]

The company I currently work for sprays their PCBs with lacquer to protect the circuits. We do have a lot of projects with military standard, maybe that's why.
I have a different background than electronics and only work in the CAD department so no idea if this is the usual practice.

[Z.O.R.G.]

The military version is called conformal coat.  Basically, it's a  expensive version of polyurethane that will not interact with the electronics or solder.  It's used to keep moisture off electronics that can't be sealed (it's really bad to have an airtight box in an unpressurised section of an aircraft) and to protect electronics from vibration and shock.  I chose nail polish over polyurethane as I didn't need to use much, it comes with its own brush and it was under $2 at Walmart.  

[NT2C]

The military version is called conformal coat.  Basically, it's a  expensive version of polyurethane that will not interact with the electronics or solder.  It's used to keep moisture off electronics that can't be sealed (it's really bad to have an airtight box in an unpressurised section of an aircraft) and to protect electronics from vibration and shock.  I chose nail polish over polyurethane as I didn't need to use much, it comes with its own brush and it was under $2 at Walmart. 

I'm a lazy bastard.  Spraying is easier than brushing.  Of course, it depends on the size of the board.  Video game boards back then were as big as 18"x12", sometimes bigger.

[MacWa77ace]

I had to replace a power supply module for my clothes washer and that whole thing had about a 1/4" thick coating over the whole thing. Makes sense.

The difference between a micro RDS and an RMR is that the electronics are coated.
RDS = Red dot site
RMR = Ruggedized micro reddot



You'd think that the more expensive trail cams would use gold plated contact and other materials that don't corrode.

[tirls]

I asked someone working in assembly. Most of our coatings are by European producers and only available in larger quantities, but we do have one called HumiSeal 1B73EPA that is available in small spray cans.