I am working on a outdoor watertight electronic enclosure that has to stand up to the elements as it sits on rooftops. Has a PCB inside it.
What are the pros and cons of paint or plating?
cost, eco-friendly, etc.
Still deciding on sheet metal or palstic. Any thoughts?
Also, what is the best way to seal it from rain and elements?
Thanks for any insights/advice.
Outdoor enclosures are usually plated and painted. Either one by itself doesn’t offer sufficient protection from the elements. Some paint companies claim durable coatings, but these are often special purpose and expensive. Plating and painting are commodity processes and somewhat inexpensive.
All plating processes are environmental disasters. Get used to it. It’s why plating companies ensure they have beautiful flower beds and green lawns outside their plant, behind doors it’s acrid, steaming, evil brown vats with odd wire parts cages above.
Plastics don’t weather well the abuses of long term environmental exposure regardless of climate. Ultraviolet light is murder to polymers, as is repeated thermal cycling. Also, assuming your outdoor enclosure with a PCB is for some type of electronic communication, EMC will be an issue as there is no way to ensure long term shielding of outdoor installed plastics enclosures, except for metal foils or internal chassis.
In terms of sealing, by design there are never up facing openings, other vents, seams or windows require screens and / or multiple turns blocking direct spray access. There are numerous types of gaskets available.
Ingress Protection describes levels of water and dust susceptibility. NEMA and assorted telco standards have design guides.
Walk around and look at cable repeater boxes, telephone switch boxes, highway signage, etc. You’ll start to recognize intent.
Look at Hoffman Enclosures. They’re pretty much the gold-standard weatherproof electrical box in the US
NEMA-3R or NEMA-4 is what you’d be looking at (pretty sure)
have you thought of enameling? it might offer a nicer finish even if it isnt impact resistant.
you could always go with a PVD over the plating as well. Might be helpful if near a coastal area where you have higher levels of salt and acidic air.