Coating/spray to protect circuit boards/electronics on playa

[junglesmacks]

Does anyone have any experience with raw circuit boards and keeping them playa dust/corrosion free via any type of spray/cleaner/whatever?

I'll be sealing my PIC LED controller board in a ziploc, but will still have wires running out of it and have it be accessible in order to switch modes.. meaning.. dust will get in. Is there anything that I can spray on it to repel/protect? I've heard scotch guard on speaker cones before. Wondering about the same thing for electronics.

Backup plan: spray electrical contact cleaner every night.

[Raymaker]

plasticine or putty around the wire and hole, tape around that to make sure it holds in place?

[FIGJAM]

This may work.

http://www.google.com/products/catalog? ... C4Q8wIwAQ#

[junglesmacks]

Oooooo.. umm... wow. True. I feel weird about plastic coating an entire PC board with IC chip, MOSFETs and all, though. Seems like that may be a little aggressive.. but.. hm. Very interesting. Might be cool to play with a spare board.. which I do have.

[FIGJAM]

If you don't like the result, it can be pealed off.

[portaplaya]

Playa dust is not corrosive in an arid environment. It only becomes corrosive once some water is introduced. Unless your circuitry is moist, sitting in a humid environment or having water introduced in some other way, nothing bad is going to happen to the circuitry. Just make sure you dust it off completely before you head home.

I would actually avoid the spraying of electrical contact cleaner every night, since that is adding a solvent and possibly activating the dry base in playa dust.

After all, people bring generators, cars, battery powered things and other devices that have electrical connections. None of these die on-playa from the dust corroding them. But they must be cleaned before going home or coastal humidity can have an adverse impact.

[SnowBlind]

Does anyone have any experience with raw circuit boards and keeping them playa dust/corrosion free via any type of spray/cleaner/whatever?

We've had PCBs on our bikes that are exposed directly to the playa dust. They've been out there a couple of years, and they are definitely showing their age now. At least one pair has gotten moist at home though, so that accounts for some of it. Hard to say how they would have done if we had taken better care of them.

Altogether, they've fared surprisingly well, though we've had weird issues with them, which may have been related to playa dust, or may be design issues. We're still debugging

Our boards were the cheapest type you can get, with no solder stop or silk screen. I've heard that the solder stop basically acts like a playa dust repellent and you just wipe it off a little. Not sure how well that works cause skimped on that. We've considered coating them in plastic, but never done that.

These particular boards need to be open, cause they are covered with SMD LEDs. For a controller board, I would but it in a case or something, to give it basic protection, but not worry about it being hermetically sealed. If it's in a bag and the wires go out, I think that's fine.

Also, depending on what load it's driving, consider that there could be heat issues. We have one board that drives 24 half watt LEDs, and that boards needs to dissipate a fair amount of heat. I wouldn't want that in a sealed bag.

[junglesmacks]

All very good points.. thanks much! Didn't think about the moisture/activation/etc issue with the spray. I think I'll just chance it and try and give it basic protection. The whole board is only $40, anyway.. not that it's chump change, but it's not a $1000 rig or anything.. just a MOSFET LED controller.

Sick, by the way.. http://picprojects.org.uk/projects/480/pro483/

This thing will run 16 different programs and power up to 3 watts per channel of LEDs. 150 per channel is cake.. x 8 channels = 1200 controlled LEDs.

Anyway.. back to sewing. Don't get me started..

[Zhust]

I'm making "Cheapy Blinkys" to give out. I have a lot of transistors and LED's I've scavenged from things, but I find when I work on a project, I'm too often looking for specific values or properties. I designed the circuit around an 8-pin PIC with an NPN common-base circuit at each output. That way I can chain a few LED's and drive them from the 9V battery (of which I also have a lot of from work, as we replace the batteries even if they're pretty good). The PIC pins source or sink 20-25mA, so the common base amplifier acts as a constant-current source at a little less than 20-25mA. In the end, they're not very cheap, but a pleasurable way to dispose of 9V batteries, LED's, and transistors.

Anyway, my plan is to coat them in clear silicone caulk: it is waterproof, it will diffuse the LED's nicely, and I can use it for artistic goopy goodness. I want to make something that will last quite a few years rather than some watch-battery-spilling cheaply-made junk.

[gyre]

Jay, don't.

Clear silicone conformal coating, made for circuit boards.
Very tough.

[junglesmacks]

Clear silicone conformal coating, made for circuit boards.
Very tough.

BING!

http://bestbyte.net/merchant/merchant.m ... re_Code=BB

[Zhust]

Jay, don't.

Clear silicone conformal coating, made for circuit boards.
Very tough.

Oops ... too late! I just got started on it. Besides, I do want the weird structures you can make to be part of the illuminated design. I have 10 of them and they all have different colors and kinds of lights, so each one will be very unique anyway.

But in the future, that silicone coating seems pretty sweet.

[gyre]

Silicone caulk is usually very corrosive.

Schneemorehead acrylic may be better.

[Zhust]

Silicone caulk is usually very corrosive.

Schneemorehead acrylic may be better.

I did a little poking around and found an old article that identified acetic acid as a byproduct during curing. Not for nothing, but vinegar, while far from inert, is also far from highly corrosive. As it's too late already, I guess I have to take my chances and hope for the best.

The silicone sure makes the lights look funky, though. I made it blend some of the colors together, or just made diffusers, or gave them soft-serve ice-cream nipples. I can't wait until they're dry enough so I can play around before all the metal rots away!

[gyre]

I've seen it strip chrome.

[Zhust]

I thought of you all when I saw this: LED Seal from LED Supply:

Coats and insulates electonic components. Re-insulates cracked or broken electrical insulation. Coats all surfaces with a non-permeable elastic finish. Prevents corrosion and damage due to moisture. Seals small cracks in rubber, cement, or painted surfaces. Adheres to glass, metal, and vinyl surfaces.

[CaverX]

Key word, conformal coating.

[gyre]

Some aren't clear, like very high voltage coatings.

Tubelite always had adhesives that wouldn't affect other plastics and rubbers.
Not sure they are still around.
Many unique products.

[BBadger]

Can you seal the board with exception to heatsinks, and then use a sealed switch on a cable to switch modes? That way the circuitry never gets exposed and it's easier to hit the external button to switch modes.