Omnikey Plate repaint

User avatar
TNT

28 Dec 2020, 17:36

Happy Holidays everyone!

I need some help with repainting a plate. All of the plates on my keyboards have a little rust or areas where the paint has "warped" or is flaking off. All of those are ALPS boards, so I've never wanted to bother with desoldering all the switches. I've always just thoroughly cleaned the plates and moved on.

However, I've recently got an Omnikey in very bad condition. Rust all over the plate, very dirty, etc.
Since I will replace the switches anyway or at least remove them for cleaning, I'm inclined to give the backplate a new coat of paint. However, how would I do this? Do I have to sand off the old paint by hand, then repaint everything? What paint should I use, should I bother with some rust-stopper before the paint? A whole lot of questions :?

What about sandblasting? I cannot do it myself but would have to send it to some sort of service company. I have one more plate that I could send in, but that one is in a rather good condition and does not necessarily need a repaint. The whole thing is also not very cheap tbh. Worth it or not?
There are simple tutorials online about how you can build a simple DIY sandblaster and I already have a compressor. Anyone here who has tried that? I'm not sure if too good results can be expected from that...

Any advice on the procedure in general and anything I have to have in mind when doing this with an Omnikey plate?
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jsheradin

28 Dec 2020, 17:51

You'll definitely need to remove the rust before you paint it but sandblasting and all that isn't necessary.

I would:
  • Remove the switches
  • Get the bulk of the rust off with a wire brush or 220 grit sandpaper
  • Soak the plate in Evapo-rust and rinse
  • Get it pretty smooth with some 220-800 grit sandpaper
  • Wipe it well with acetone/paint thinner/degreaser
  • Hit it with a coat or two of self-etching primer
  • Hit it with a couple coats of color

User avatar
TNT

28 Dec 2020, 20:13

Thanks for your help!

Any alternative for the evapo-rust? That stuff seems to be pretty expensive.

Heard about some people using citric acid, is that true?


Sry, just realized any decent rust-remover should do it.
Last edited by TNT on 28 Dec 2020, 20:50, edited 2 times in total.

jsheradin

28 Dec 2020, 20:26

Another option would be to do a few coats of something like https://www.rustoleum.com/product-catal ... t-reformer after sanding. Depending on how nice you want the finish, I probably wouldn't even do a color coat.

User avatar
Polecat

29 Dec 2020, 04:15

Be careful not to apply too much paint, or you'll have problems with the stabilizer clips not fitting.

I've cleaned and painted three or four Alps plates in the past few years. I don't have the time, money, or patience to mess with a bunch of fancy prep, so I just wet sanded mine with 400 and sprayed with a couple coats of Aervoe brand engine enamel from the auto parts store. All of them came out really nice, and I wouldn't do anything different if I was to do it again.

User avatar
TNT

30 Dec 2020, 01:46

Okay. My plan now is to do as jsheradin said but I'll try to go easy on the amount of paint. I'm thinking about not applying primer to the parts which are not rusted. If I manage to match the colors maybe it won't look too bad if I give them just a touch of paint or even none at all. Wdyt?

jsheradin

30 Dec 2020, 02:11

I'd do primer on the whole thing since it can affect how the color layers look. The color coat would only be needed on the front of the build plate which helps. If you don't care too much about the finish (matte vs gloss vs satin) you could just do a few thin coats of black primer and call it good. Primer is generally not as durable as paint but it's not exactly a high wear surface.

User avatar
Polecat

30 Dec 2020, 05:20

TNT wrote:
30 Dec 2020, 01:46
Okay. My plan now is to do as jsheradin said but I'll try to go easy on the amount of paint. I'm thinking about not applying primer to the parts which are not rusted. If I manage to match the colors maybe it won't look too bad if I give them just a touch of paint or even none at all. Wdyt?
If you use primer only be sure it's primer/sealer! Plain primer will not keep out moisture, and it will rust from underneath. In my car painting days I learned that plain primer outdoors would be rusty in only a week or two.

This is a Focus plate (very similar to Northgate) that I painted with the Aervoe engine enamel. Color is Cast Iron Gray. Two thin coats. If you do more than one coat either put on the second within twenty minutes, or wait three days between coats. You'll end up with a big mess otherwise (don't ask me how I know that).
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User avatar
fohat
Elder Messenger

30 Dec 2020, 15:36

Polecat wrote:
30 Dec 2020, 05:20

don't ask me how I know that
Rule for Life: Always follow paint instructions to the letter.

User avatar
TNT

31 Dec 2020, 14:32

Thanks for the photo. That plate looks very clean.

Kinda makes me think, do I even have to use a primer at all?

jsheradin

31 Dec 2020, 19:35

For bare metal it's a good idea but not strictly necessary. There's plenty of paints that don't require it such as the engine enamel mentioned. It generally won't be as durable as good prep+etching primer+color but for this application it doesn't make a huge difference. Biggest thing to watch out for is that primer-less will be easier to chip when reassembling since it won't be bonded as well to the metal. Either option should last 100 years just fine.

User avatar
TNT

01 Jan 2021, 05:50

Thanks a bunch for the help, guys! It's settled, a combination of rust remover and engine enamel will do it then.

Don't know when I will have the time since the color won't arrive before next week, but I can send a picture of how it turned out.

User avatar
TNT

17 Jan 2021, 23:27

Soo, I finished the plate today and I think it turned out pretty ok. I chose a darker color cause it looked promising and I absolutely love it. "Cast iron gray", looks exactly like a fracture or crack surface on some cast iron machine part. I wanted to treat the backside too somehow since it was coated in some way on the plate in its original state. Another layer of spraypaint sounded too much for me. So I decided to try blueing. Also turned out pretty good IMO. Wouldn't recommend it tho, too difficult to make it look decent and you'll have to grease it up a little to make it actually resistant to corrosion. I drenched it in oil for an hour and wiped it off thoroughly, so it should be ok now, but still...

So the entire procedure went like this:

  • Rust Remover
  • Sanding
  • Blueing
  • Sanding the front again
  • Spraypainting

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Thanks again for the advice!
Last edited by TNT on 18 Jan 2021, 23:49, edited 2 times in total.

User avatar
Polecat

18 Jan 2021, 02:09

TNT wrote:
17 Jan 2021, 23:27
Soo, I finished the plate today and I think it turned out pretty ok. I chose a darker color cause it looked promising and I absolutely love it. "Cast iron gray", looks exactly like a fracture or crack surface on some cast iron machine part. I wanted to treat the backside too somehow, since it was coated in some way on the plate in its original state. Another layer of spraypaint sounded too much for me. So I decided to try blueing. Also turned out pretty good imo. Wouldn't recommend it tho, too difficult to make it look decent and you'll have to grease it up a little to make it actually resistant to corrosion. I drenched it in oil for an hour and wiped it off thoroughly, so it should be ok now, but still...

So the entire procedure went like this:

  • Rust Remover
  • Sanding
  • Blueing
  • Sanding the front again
  • Spraypainting

Thanks again for the advice!
Looks great to me, thanks for sharing!

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