PCH Very High Moist Environment

have you got an advice on which spray will be the best for my PCB with this high moisture ? And will it be enough or should I use sylicon ?
THANK YOU!

I can't tell what the second coating is. Lacquer is too generic a term. You'd need to know what materials are in the lacquer.

The first material is identifed as acrylic.

Silicones are no better at moisture resistance that acrylics. Look at moisture vapor transmission rates of varoius ploymers.

For specific recommendations, contact your material supplier.

sorry, I didn't explain well! I want to know what are , in the market, the best coating sprays and if them will be the best solutions for my PCBs.

THX!

Here

http://www.circuitnet.com/experts/55993.shtml

a preson says "Silicone excels in this due the hydrophobic behavior of the material that forms the final silicone coating. Silicones are difficult to wet by water. Silicone conformal coatings are being used in highly humid environments, with high efficiency and success, even when proven under high salinity and humidity conditions." Is he wrong ?

Silicones are fine. Just be sure to use one that is specifically designed for conformal coating use. Some silicones evolve acetic acid during cure and this will tarnish the circuitry.

just the last two things (i promise =) ):

1) Is better silicon spray, like this http://uk.rs-online.com/web/p/conformal-coatings/0494714/ , or a solid one?
2) Should I cover the whole PCB with silicon or only some parts ? consider that pcb is composed by resistance,capacitos,operationa lamplifiers and gold pins.
THANK YOU!!!

I'd use a dip coating. That assures that the underside of components are coated as well.

Coat everything except the board edge contacts or any terminals that will be soldered.

Whole PCB, at least two coats.

An incubator can be considered a life supporting device, if I were to work on that, I'd make sure I've read all applying norms, design rules and use only approved components for the PCB.

You can get directions about coating and/or encapsulates from the related literature.

If you are working on a poultry project, just make sure you used clean solder, and apply the coating freely to the entirety of your board.

Regards

if you're smart enough to do all the math, surely you're smart enough to know how to Google and use a telephone

one other information : the pcb has 30 gold pins spaced 5 mm one each other. If a water drop link two of them a short circuit is made and this MUST'NT happe. Do you think that between them spray will be enough or is better use silicon in order to cover empty spaces between them and avoid drop formation ?
THX

I'd be inclined to use a polyurethane coating in this enviroment.

All non-metallic coatings will allow moisture to penetrate them.

For maximum protection, I'd dip coat the boards.

can you suggest me which dip coating material should I use ?

thx!

Search yourself.

suitable dip coating material for PCB?

consider that I should also isolate from water drop a series of 30 gold pins like these

http://www.google.it/imgres?imgurl=http://4.bp.blogspot.com/-_qFkE34UNBo/TgmrG_LcUXI/AAAAAAAAAIA/i03TB_9yV0s/s1600/processor_gold_pins_macro_by_ArminoTauruS.jpg&imgrefurl=http://ihackuall.blogspot.com/2011/06/looking-for-methods-of-extracting-gold.html&h=960&w=1280&sz=511&tbnid=R-JqDN-NT2O8AM:&tbnh=90&tbnw=120&zoom=1&usg=__x6vYQZXenU3_6mxT941YSreHSto=&docid=JZMfJvQ1o9RsVM&hl=it&sa=X&ei=QgTTUPmCEOnE4gTBz4GoCA&sqi=2&ved=0CDIQ9QEwAA&dur=171

I think that only a solid coat like silicon could isolate them. What do you think ?
THX