Conformal Coating

[JimboJones21]

Hi All,

I wanted to make an LED PCB that will last outdoors. It will be in direct contact with the environment.

Is there a spray I can use on the PCB that is clear so the LED light will come through and will protect the PCB from rain?

I was thinking clear coat that is used for paint, but wasn't sure if that was a good solution.

 

[VEBill]

Military CCAs are coated with a mil-spec "Conformal Coating". I'm not sure off-hand what the common brand names are.

If you're making a one-off, a few coats of any non-yellowing spray clear finish would probably work. The tricky bit is making sure it is thick enough to seal-off the gaps under the components. If not, then water will get in through those paths.

You can also mask-off the LED tips so that the coating wouldn't affect the light at all. Most spares will adhere to the sides of the LEDs so as to seal them off.

As always, stand-by for other comments.

True Conformal Coating has the advantage that it can be removed for circuit repairs.

 

[VEBill]

Typo: "Most SPRAYS will adhere..."

 

[itsmoked]

HumiSeal is THE conformal coating company. It's all they do. It's the only brand I've ever seen used, probably others I've just never seen any.

You need to comb thru the offering to see which one you need. Barring that you could just check with you local electronics supply place.

http://www.humiseal.com/index.html

http://www.humiseal.com/aerosols.html#

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

Electrolube make a couple of good ones. The SCC3 silicone based coating is impervious to virtually anything that won't attack the board itself.


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If we learn from our mistakes I'm getting a great education!

 

[btrueblood]

Make sure you get something that is resistant to UV degradation.

 

[electricuwe]

See:

http://www.peters.de/index_e.htm