I've been looking at and thinking about a few related topics...
- Reliability of the Arduino platform for industrial use
...and I decided to throw out this question. I've seen professional circuit boards with chips and all that are 100% waterproofed via clear-coat finishes across the whole board. Is it a reasonable, good method to just dip a whole, final, soldered circuit board, such as a completed Arduino Nano project with all wires soldered, into polyurethane or lacquer to give it a protective finish against water, corrosion, humidity, chemicals, etc?
I'm thinking of using these products specifically:
If this is a reasonable thing to do, which is better: satin, semi-gloss, or gloss?
Dipping into an (oil-based) Minwax Gloss Polyurethane 1 qt can sounds the most reasonable to me at the moment.
The one exception to this technique is to simply ensure you don't cover up any sensors that destroys their ability to function (ex: barometric pressure sensors, humidity sensors, etc). Also, I'm sure the board won't cool as well...
Looks like the keyword I needed was "conformal coating." Here's one source mentioning polyurethane as a good choice: http://www.conformalcoating.co.uk/Conformal_Coating_Material_Types.php