Conformal Coating Tips

[gotnothing]

I am thinking about adding conformal coating to my Gotway Tesla pcb. I've already waterproofed the shell but I wanted to stay on the safe side and protect the pcb as well.

Has anybody had success applying the coating? If so, I would love to know if you have any tips on how to carry it out. 

I realize there are videos for drones but I haven't found any for doing this to an euc board (which could potentially get hot).

Thanks!!!

[cdoe]

I went with plastik 70 from kontakt chemie in aerosol can. May not be the best option available but so far so good. It was relatively easy to get and seems to "just work" on my ks 18l

[gotnothing]

Thanks for the input. Did you end up disassembling the whole board first? Also were there any areas you avoided spraying? Any more details you can provide helps a lot. 

I am mostly worried about the mosfets getting coated and overheating as a result.

[cdoe]

I did removed board from wheel and disconnected it. I've sprayed underside in 3 thin layers waiting for each one to dry and changed stock rubber "gasket" when putting board back. I've also used anti- corrosion lube on contacts which looked flimsy - things like led and such.

Luckily for me there's a video on youtube which shows most weak points for my wheel which I used as a guidance when servicing the wheel. 

 

[gotnothing]

Alright, thanks for your feedback. Looks like I have to disconnect the circuit board from the heatsink first. The whole thing feels so sketchy but I fear that without it I may run into corrosion issues. I did waterproof the shell and verified that no water is coming in touch with the board itself 

Thanks for your help, I may ask you again if I have any other questions.

[Rywokast]

whats wrong with the waterproofing already applied to the board?

[cdoe]

I guess nothing. In my case I just wanted to be 200% sure. Everyone has a different story with euc but getting warranty here is like getting blood from stone. Also if there are signs of water inside that's not under warranty (terms of sales here pretty much)

Edited December 8, 2019 by cdoe

[Tinkererboi]

Planning to do my first coating on a 16x. Anyone knows if it messes with heat dissapation? Bought a broken gt16 with burnt out board to fix once, it had a coated board. Was wondering if the coating had anything to do with it burning up.

[Seba]

5 hours ago, Tinkererboi said:

Planning to do my first coating on a 16x. Anyone knows if it messes with heat dissapation? Bought a broken gt16 with burnt out board to fix once, it had a coated board. Was wondering if the coating had anything to do with it burning up.

Conformal coating doesn't impact heat dissipation significantly. If particular board design tends to burn, it's almost always a design/layout flaw. 16X mainboard should be already coated, as AFAIK King Song applies silicone conformal coating to all their mainboards. At least in all of my KS wheels mainboard was properly coated.

[Tinkererboi]

16 minutes ago, Seba said:

Conformal coating doesn't impact heat dissipation significantly. If particular board design tends to burn, it's almost always a design/layout flaw. 16X mainboard should be already coated, as AFAIK King Song applies silicone conformal coating to all their mainboards. At least in all of my KS wheels mainboard was properly coated.

Ahh yep forgot king song mainboards are already coated. Brain fart moment.

[Planemo]

I think they all are now, even Gotway (shock horror) I still wouldnt want to get it wet though!

[SteveO]

Do Veteran Sherman control boards come with any conformal coating?

[drader]

For RC hobbies people have been using Corrosion X as a waterproofer. It is basically a "crawling oil", and won't affect electrical signals.

[Tawpie]

Don’t get the coating on connectors or any parts with adjusters (little screwdriver adjustments).

Back in the day we used a product branded “Humiseal” that was really Future Floor Polish (an acrylic floor wax). For demanding applications we used silicone, but that rendered the board unrepairable and was so thick it DID adversely affect heat dissipation. The exotic material was parylene, which is a vapor deposition process but it was the best. Invisible to the eye and very difficult to get off if you needed to replace any parts.

Humiseal will absorb moisture and cause issues with high impedance circuits (not found on EUCs), it is ok with drops of water and condensation but we also added a UV dye and hand inspected every board under a microscope for pinholes. Silicone is super messy and contaminates everything that gets near it but it is tough, structural, and pretty much everything proof. Parylene is horribly expensive. No silver bullets.

We had to be super anal about cleaning the boards prior to coating because any ionic contamination that remains on the board either keeps the coating from adhering properly (silicone and parylene) or gets sealed in and causes corrosion (Humiseal and its cousins).

But we were making things that you really really really didn’t want to fail.

Honestly, you could probably use exterior spray paint and be just fine. Take the board completely out, mask the connectors and any adjustment screws with tape and go to town. But if water gets under a connector body or wicks in by running down the wires you’re still toast.

Edited February 23, 2021 by Tawpie

[Rywokast]

4 hours ago, Tawpie said:

Don’t get the coating on connectors or any parts with adjusters (little screwdriver adjustments).

Back in the day we used a product branded “Humiseal” that was really Future Floor Polish (an acrylic floor wax). For demanding applications we used silicone, but that rendered the board unrepairable and was so thick it DID adversely affect heat dissipation. The exotic material was parylene, which is a vapor deposition process but it was the best. Invisible to the eye and very difficult to get off if you needed to replace any parts.

Humiseal will absorb moisture and cause issues with high impedance circuits (not found on EUCs), it is ok with drops of water and condensation but we also added a UV dye and hand inspected every board under a microscope for pinholes. Silicone is super messy and contaminates everything that gets near it but it is tough, structural, and pretty much everything proof. Parylene is horribly expensive. No silver bullets.

We had to be super anal about cleaning the boards prior to coating because any ionic contamination that remains on the board either keeps the coating from adhering properly (silicone and parylene) or gets sealed in and causes corrosion (Humiseal and its cousins).

But we were making things that you really really really didn’t want to fail.

Honestly, you could probably use exterior spray paint and be just fine. Take the board completely out, mask the connectors and any adjustment screws with tape and go to town. But if water gets under a connector body or wicks in by running down the wires you’re still toast.

if everyone just did what kingsong does which is put the boards at the top then this would be a non issue... if its really pouring ill put a waterproof backpack cover on it but otherwise it is basically impossible for water to get to the board

[.....]

On 2/3/2021 at 8:56 AM, SteveO said:

Do Veteran Sherman control boards come with any conformal coating?

As far as I can tell, the Serman board is HEAVILY coated and of a good layout. Its also at the top of the wheel. I'm not saying water wont get to it, but itll be much easier to perevent than the dumb as f**k design of placing it at the bottom of a plastic bowl with holes in the top.

40 minutes ago, Rywokast said:

if everyone just did what kingsong does which is put the boards at the top then this would be a non issue... if its really pouring ill put a waterproof backpack cover on it but otherwise it is basically impossible for water to get to the board

Isnt it odd. Chinese companies have been known to ignore intellectual property claims, yet the small number of euc companies ALL in China, won't bother to inspect their competition and mimic what works, even if its something so simple as board location... Personally, I'd reverse engineer EVERY wheel that was my competition and 'steal' the best ideas of each. Hardest part would be to pretend it was ALL my idea in the first place. DUrr, moral or not, THIS is how shit gets done and progress gets made. Built it right, sell it fast and save back a few $$ to have your lawyers make it all fit.

Edited February 23, 2021 by ShanesPlanet

[Rywokast]

Just now, ShanesPlanet said:

As far as I can tell, the Serman board is HEAVILY coated and of a good layout. Its also at the top of the wheel. I'm not saying water wont get to it, but itll be much easier to perevent than the dumb as f**k design of placing it at the bottom of a plastic bowl with holes in the top.

Isnt it odd. Chinese companies have been known to ignore intellectual property claims, yet the small number of euc companies ALL in China, won't bother to inspect their competition and mimic what works, even if its something so simple as board location...

the problem with the sherman compartment is that the small compartment housing the board is just sitting on top of the board, it doesnt go all the way and extend down beyond it like KS wheels if you know what i mean... so while thats certainly better than the side, with the seams it is still possible for water to get in, though highly unlikely.. the ks top is one piece that goes all around the wheel and extends down beyond where the board sits so unless gravity were to reverse, no water is getting up inside of it... but yea, the only reason gotway doesnt is the same reason their last ten wheels look the exact same lmao... because theyre cheap af and dont care as long as its fast, cheap and easy to produce/get out the door thats all that matters.. all of their eucs look and feel like cheap kids toys compared to any KS, inmotion or ninebot euc

[.....]

3 minutes ago, Rywokast said:

the problem with the sherman compartment is that the small compartment housing the board is just sitting on top of the board, it doesnt go all the way and extend down beyond it like KS wheels if you know what i mean... so while thats certainly better than the side, with the seams it is still possible for water to get in, though highly unlikely.. the ks top is one piece that goes all around the wheel and extends down beyond where the board sits so unless gravity were to reverse, no water is getting up inside of it... but yea, the only reason gotway doesnt is the same reason their last ten wheels look the exact same lmao... because theyre cheap af and dont care as long as its fast, cheap and easy to produce/get out the door thats all that matters.. all of their eucs look and feel like cheap kids toys compared to any KS, inmotion or ninebot euc

And kingsong would be the first brand I'd tear into to mimic. Take their finesse, make it much bigger and BAM, quality euc that keeps up with the big boys. Add some better metals and flexible panels... done and done.  You want superb algos for ride feel==Kingsong. You want proper placement of circuit boards and even weight distribution of batteries.... kingsong. YOu want a KS fanboy to hate you.... goelock it.

Edited February 23, 2021 by ShanesPlanet

[mike_bike_kite]

There must be something wrong with me Shane. I've liked two of your posts already this morning.