Where can one get 'conformal coating'?

[swbluto]

According to ebikes.ca in regards to waterproofing a controller, "It is pretty difficult to properly seal the Crystalyte controller boxes, with the buttons and key switches and many wires and all. However, it is not that difficult to open them up and apply waterproof conformal coating directly on the PCB. This makes the controller much more resilient to wet weather." So now the next step is getting "conformal coating". Where would one usually get this stuff and under what name? I've tried my local hardware shops and the seemingly closest thing they've had was "Spray-on silicone". It also didn't seem like they've had "dielectric grease" and I'm under the impression the only adequate substance is something you can brush on due to the leads sticking out of the board for capacitors and whatnot.

Also, are there any potential wetness problems with pedal-first controller arrangements beyond the throttle? It seems the hall-sensors could still be damaged in the motor(Or, rather, short-circuited), but that doesn't matter with pedal-first arrangement, right(I just noticed that was the Diagnostics page first problem mentioned so I assume the largest)? I don't really mind pedal-first since I don't really want to use the throttle during take-off, anyways, for efficiency reasons.

 

[Jeff]

You can buy a clear polyurethane spray finish at your local big box home improvement store and achieve professional results.

Most consumer grade coatings are applied by spray.

Regards, Jeff

 

[swbluto]

According to ebikes.ca in regards to waterproofing a controller, "It is pretty difficult to properly seal the Crystalyte controller boxes, with the buttons and key switches and many wires and all. However, it is not that difficult to open them up and apply waterproof conformal coating directly on the PCB. This makes the controller much more resilient to wet weather." So now the next step is getting "conformal coating". Where would one usually get this stuff and under what name? I've tried my local hardware shops and the seemingly closest thing they've had was "Spray-on silicone". It also didn't seem like they've had "dielectric grease" and I'm under the impression the only adequate substance is something you can brush on due to the leads sticking out of the board for capacitors and whatnot.

Also, are there any potential wetness problems with pedal-first controller arrangements beyond the throttle? It seems the hall-sensors could still be damaged in the motor(Or, rather, short-circuited), but that doesn't matter with pedal-first arrangement, right(I just noticed that was the Diagnostics page first problem mentioned so I assume the largest)? I don't really mind pedal-first since I don't really want to use the throttle during take-off, anyways, for efficiency reasons.

For those who've seen this post in "Electric vehicles - General Discussion", sorry for the repetition. I finally realized I meant to originally post to this board after searching for my thread.

 

[Zoot Katz]

I bought a small bottle of urethane conformal coating at the electronics parts shop.
Dielectric grease I found in the automotive department at Canadian Tire.

 

[MidniteTweeker]

http://www.mcmelectronics.com/product/20-2242

for example....

MT

 

[John in CR]

http://www.mcmelectronics.com/product/20-2242

for example....

MT

$24 a can and probably about the same stuff as $3 urethane in a spray can for our purpose. Are we really going to check it with a black light or just spray an insurance coat. For someone who never plans to modify or repair, isn't a coat of epoxy fine too if you have it laying around?

 

[swbluto]

The $20+ per can doesn't sound appealing for a simple waterproof coating nor does ordering it through specialty retailers online(Due to price and shipping times).

And, the "local electronics shop" around here seems to be Radio Shack and they didn't have anything but I'll keep trying. Would some bigbox retailer like "Home Depot" or "Lowes" have something related to urethane? Who would have urethane sprays?

 

[Sturdly]

If you do choose to use something other than an "approved for electronics" type of coating be sure it can stand the heat, is non corrosive, has good insulation qualities and to let it cure completely before firing up your motor. We have used Humiseal at work for decades and no problems. Recently when using a new water borne coating we found that until it is totally cured it is conductive! I would stay away from the water clean up varathanes and the like just to be on the safe side.

 

[Zoot Katz]

The $20+ per can doesn't sound appealing for a simple waterproof coating nor does ordering it through specialty retailers online(Due to price and shipping times).

And, the "local electronics shop" around here seems to be Radio Shack and they didn't have anything but I'll keep trying. Would some bigbox retailer like "Home Depot" or "Lowes" have something related to urethane? Who would have urethane sprays?

This is what I bought- $10 for 2oz.: http://www.mgchemicals.com/products/4223.html?PHPSESSID=d6ba69ec251983cf059207b368e00a3b
There's a distributer locator on the site. Maybe you can find someplace better than Radio Shack.

 

[MidniteTweeker]

Use whatever you want. Just be aware that 'conformal coatings' were specifically designed for the application and meet all the unique requirements for use around electrical components, plus survive in humid conditions without growing a coating of mold.

Among other things that means that it will penetrate and fill small cavities, flow under and around components, etc. And when it cures it will not expand or contract and put stress on components like some epoxies are known to do. Also, some epoxies are exothermic during cure, and when the volume exceeds a certain critical level the results can be really entertaining.

MT

 

[ngocthach1130]

The service from this company would help. Check out the video. If they can water proof cellphone and let it operate underwater, i don't see why they can't do it for our controller. $70 quote isn't a bad price. Will be available soon

http://www.ohgizmo.com/2008/07/22/golden-shellback-waterproof-gadget-coating-your-fish-wants-an-iphone/

 

[wrobinson0413]

.

 

[disadvantage]

Why not try brushing RTV silicone caulking over your circuit board? Wouldn't that work?

That material is low cost and easy to find, and you don't need fancy-schmancy equipment to apply.

 

[JB_EB]

In Australia, you can buy spray cans of this Conformal Coating in local hobby electronic stores. I don't know your US stores, but maybe try searching some of the electronics supply companies with on-line stores. (Maybe even Radio Shack?)

I wouldn't use spray-on silicone personally. The real conformal coatings are formulated to allow repair of the PCB by removing the coating with acetone-type liquids. Some even allow you to de-solder and re-solder without removing the coating.
Good luck
JohnB

 

[swbluto]

In Spokane, the closest thing they had to an "Electronics Hobby Store" was Radio Shack and that's shifted quite a bit from circuit level electronics to consumer electronics like cell phones.

But, now that I'm Seattle, I have "Fry's" accessible to me by a 1.5 hour bus ride! Yes! Mecca! Nirvana! Valhalla! The Krishna of electronics! And, they not only had "conformal coating", they had three different types! Silicone, Urethane and something else... I forgot. I got the Silicon since it had the highest temperature rating. Sure did beat the price and inconvenience of ordering it on-line.

Despite Fry's definite advantage over the quite pitiful Radio Shack, they didn't have "Everything". No where did I find a current sensor, like a hall-effect one or a current shunt, nor did I find multiplexed displays or multiplexed display drivers. So it looks like I'll be ordering some components online.

And an employee's insistence on "everything" being online was met with experimental failure as I challenged a search for a small cable part that was hanging near by. It didn't show up. :lol: So, I had my doubts a current shunt would've shown up if they had it. But, I did check just about every electronic component group they had!

 

[rkosiorek]

one of the many companies that makes the stuff is TechSpray.

http://www.techspray.com/pindex.htm

i have used several of their Fine-L-Kote #2102, #2104 and #2106 that i have bought in 12oz. spray cans. in Canada you can get it at Electrosonic. in the US you can get it at Mouser and Digikey. something about homeland security restrictions prevents the stuff from being shipped across the border in small batches. check the TechSpray website most list dealers and distributors.

have you tried the Yellow pages?

rick