Moisture barrier coating

[Higgler]

Could anyone suggest a spray coating that will seal small electronic boxes 2" x3" x4" size having rf connectors.
We have a part with hot/cold temp and altitude cycling in an environmental chamber, and don't want moisture sucked inside which may change the part performance. The parts are really simple purchase vendor rf parts.
These small RF boxes are a fairly tight fit in general, but I'll like to add a spray or dip sealant to add an extra measure of moisture penetration resistance.

I realize hermetic seals are the optimum, but they would be expensive and hopefully there's a routine to heat the part to remove moisture, then seal with spray coat XYZ routine.

Thanks,
kch

 

[IRstuff]

You can buy spray conformal coat at your local electronics supply store. Fry's and Orvacs in Fullerton, CA carry the product.

TTFN

 

[Higgler]

I have some of that from a local store.
Is that used as a good moisture seal? It's pretty thin so it flows under circuits and I thought it was mostly to prevent short circuits. I was trying some out recently and thought it might flow inside my housing and maybe not really seal the unit. My unknowing brain thought maybe a thicker coating of some paint on material, then maybe a parylene topcoat. I was hoping someone maybe just went through this and had some environmental results.

Thoughts?
kch

 

[IRstuff]

I'll have to check the can I have at home.

TTFN