geekhack

geekhack Projects => Making Stuff Together! => Topic started by: rampantandroid on Fri, 27 May 2016, 16:45:30

Title: Waterproofing a custom keyboard
Post by: rampantandroid on Fri, 27 May 2016, 16:45:30

Hey everyone,


I've been randomly thinking about how it might be possible to waterproof a keyboard. I've been thinking that after seating the switches in the plate, a silicone sealant around the keys should prevent and liquids from getting below the case and only to PCB, in addition to protecting the switch as long as the sealant covered the seam between the two switch housing pieces.


Is this a wise thing to do however? All silicone sealants I've used (like what you use around a shower or sink) peel off pretty easily and leave minimal residue behind. My concern would be the sealant getting inside the switch however? Additionally, I'm wondering about durability - just the act of removing a keycap might break the seal?


Has anyone ever tried this/given this a bit of thought?

Title: Re: Waterproofing a custom keyboard
Post by: xtrafrood on Fri, 27 May 2016, 20:49:34

What you could do is buy a keyboard model from a company that also sells covers (Unicomp and Ducky come to mind). I think Unicomp has a cover for all the keyboards they sell, even the giant PC122 keyboard. KUL keyboards ship with a cover but AFAIK the cover is not silicone or flexible like Unicomp and Ducky keyboard covers.

You can seal the plate off but that won't stop liquids from splashing up into the slider. Seems like a protective cover would be the most effective solution for modern mechanical keyboards.

It's not impossible, there is a cherry mx like optical switch (Adomax's Flaretech switch) that can withstand some water but it won't prevent sticky liquids from gunking up the spring mechanism. What about a skirt that fits over the plate so that the user could remove it to access the switches? No liquids on the PCB and the user could open a gunky optical switch for cleaning. Would be an awesome opportunity to build a case and a plate that allows the user to open up the switches. I would imagine that the plate would need to be modified so that the silicone layer could lock into place, and the silicone layer should extend over the case for maximum protection.

Title: Re: Waterproofing a custom keyboard
Post by: merlin64 on Sun, 29 May 2016, 01:06:32

You can do what Deck did for the police keyboards and put a thin piece of plastic over the entire keyboard that cover both plate and switches. The Keycaps hold it in place

Sent from my SAMSUNG-SM-G900A using Tapatalk

Title: Re: Waterproofing a custom keyboard
Post by: DeTommie on Tue, 31 May 2016, 04:18:47

Quote from: merlin64 on Sun, 29 May 2016, 01:06:32

You can do what Deck did for the police keyboards and put a thin piece of plastic over the entire keyboard that cover both plate and switches. The Keycaps hold it in place

Sent from my SAMSUNG-SM-G900A using Tapatalk

Like plastic wrap / cling film?

Gotta love ghetto-mods  ;)

Title: Re: Waterproofing a custom keyboard
Post by: xtrafrood on Tue, 31 May 2016, 09:36:02

PBT supreme, and plastic wrap? Deck's engineers could probably waterproof their keyboards with PBT if someone asked them to do so :))

Title: Re: Waterproofing a custom keyboard
Post by: Findecanor on Tue, 31 May 2016, 11:50:16

Isn't the membrane in the Deck keyboards made from thin rubber moulded in a special shape? I have read it likened to condoms...

I once got a water-proofed mechanical keyboard. It was a cheap keyboard with Aristotle switches (Cherry MX clones) that had been modified to be waterproofed. The metal plate had been replaced with a rubber membrane that sealed against water. There were also rubber plugs over holes in the bottom of the case. No stabilisers.

[attach=1]

The openings in the membrane are snug against the keycap's stem. The problem is that the key feel is severely impaired. It was very mushy and the keycaps touch against the rubber when they bottom out creating a suction effect which delays the keys from going up again.

I took it apart and desoldered the switches for something else, but since then I've heard that Aristotle switches don't last very long.
I still have the membrane if you want it, but I have cut away for one or more switches in it because I wanted to try if  I could reuse it for switch silencing.

Title: Re: Waterproofing a custom keyboard
Post by: xtrafrood on Tue, 31 May 2016, 12:07:29

Oh, that membrane looks bizarre. My thought was to have a membrane that stopped near the top of the plunger housing. yesh 

Title: Re: Waterproofing a custom keyboard
Post by: MajorKoos on Tue, 31 May 2016, 14:03:30

You could opt for something high-tech like NeverWet.
    https://learn.adafruit.com/neverwet-electronics/overview

The more traditional route would be a spray can of non-conformal coating - a type of non-conductive varnish - to spray over the board and all the components.
It is a varnish though, so you'll have to keep the connectors and switches clear of the stuff.  Dielectric grease could prove handy as well, but it's pretty viscous.

Title: Re: Waterproofing a custom keyboard
Post by: xtrafrood on Tue, 31 May 2016, 14:23:47

Ohhhh, new (ish) hydrophobic coating. Cheers

Title: Re: Waterproofing a custom keyboard
Post by: Data on Tue, 31 May 2016, 14:44:33

Mask your switch tops and USB port, then spray both sides of the PCB with this crap:

(http://i.imgur.com/Z71OVau.jpg)

This mod is probably permanent...  But I'm sure you knew that already.   :P

Title: Re: Waterproofing a custom keyboard
Post by: rampantandroid on Tue, 31 May 2016, 16:36:48

Quote from: Data on Tue, 31 May 2016, 14:44:33

Mask your switch tops and USB port, then spray both sides of the PCB with this crap:

Show Image

(http://i.imgur.com/Z71OVau.jpg)

This mod is probably permanent...  But I'm sure you knew that already.   :p

Hmmm...I wonder if something like plastidip would work then.


I'm not talking about making the thing stand up to full immersion, but rather a spilled drink. It's not likely to get below the keycaps and into the switches via the stem I think - it is more likely to go down through the switch cutouts onto the PCB and possible into the switches at the seam between the top and bottom. As such, my only goal here is to just seal the switch cutout in the plate and the area around the switch where it meets the plate.

Title: Re: Waterproofing a custom keyboard
Post by: xtrafrood on Tue, 31 May 2016, 16:46:53

Aw, no industrial grade waterproofing? :'(

(http://img.directindustry.com/images_di/photo-mg/15334-2420997.jpg)