why the silicone sealer on pcb boards ?

[petehall347]

wondering why the battery packs i have been looking at have a coating of white silicone type stuff covering them ? its just i had to remove it from a board to repair it and wondered if and what i should replace it with ?
these are the 80v power tool packs .
only thing i can think of is to help stop bits falling off with the vibrations from the tools .
p.s it comes off ok with petrol and an old toothbrush . and patience .

[stj]

Re: why the silicone sealer on pcb boards ?

probably to keep moisture out of the circuits.

[petehall347]

Re: why the silicone sealer on pcb boards ?

they appear to have been clear lacquered first then the white stuff .

[SMDFlea]

Re: why the silicone sealer on pcb boards ?

liquid electrical tape is what you want, good stuff but fairly expensive .

[petehall347]

Re: why the silicone sealer on pcb boards ?

do i actually need to use the white stuff or can i just use the pcb lacquer ? as that would surely keep out damp as that's what it is for .
it crossed my mind whether it is used to hold back fire in case the boards decide to go up in flames .

[SMDFlea]

Re: why the silicone sealer on pcb boards ?

yes you could just use lacqer.if you want to fill it with silicone get some specially for pcb`s ,neutral cure RTV.

[petehall347]

Re: why the silicone sealer on pcb boards ?

thinking of getting this one as will need more in the future . https://www.ebay.co.uk/itm/293436685...IAAOSwbTVeJ2zH

[stj]

Re: why the silicone sealer on pcb boards ?

that's some nasty shit - you have to use it outdoors!

i use a chinese version of this:
https://www.aliexpress.com/item/32949184183.html

[petehall347]

Re: why the silicone sealer on pcb boards ?

outside is fine for me .. well so long as its not raining that is .