Electroplating a Model M Steel Plate

[emdude]

I have been restoring a Model M 1390120 and a 1390131 whose steel plates both have a bit of corrosion. While I could just sand the rust spots down and then coat the whole thing with Rust-Oleum, I'd hate to have to mess with the nice rainbow-ish electroplated sheen that these older steel plates have.

Would it be possible to re-electroplate these steel plates to have a similar sheen? I'm no chemist and having never attempted something like this before, I am not sure what exact kind of solution and material I would need to achieve this particular effect. Would it even be practical to try this?

From my own cursory online research, I found images of jewelry electroplated (electroformed?) like so (which is basically what I would like to achieve):

[Findecanor]

Most "electro-plating" is for plating a metal with an even layer of another metal, not to get it splotchy like that.

I remembered an old thread on another forum and found this link: https://www.sculptnouveau.com/Details.c ... category=6

[fohat]

I think that shiny yellowish tinge on the earliest heavy plates came from some sort of heat treating process. I think that it was a side effect - not something that was deliberately sought.

[emdude]

I had thought the finish was the result of electroplating based on what someone said in some thread I read a while back, I guess that isn't actually the case!

Most "electro-plating" is for plating a metal with an even layer of another metal, not to get it splotchy like that.

I remembered an old thread on another forum and found this link: https://www.sculptnouveau.com/Details.c ... category=6

Thanks for the link!

[chzel]

https://en.m.wikipedia.org/wiki/Chromat ... on_coating

[snuci]

https://en.m.wikipedia.org/wiki/Chromat ... on_coating

Thank you for that link! I always wondered about this and if it was specific to some type of heat treatment and now it makes sense. This particular board must have been dipped from the right side, giving it the pattern that emdude is desiring by accident.

Early Model M Interior back plate

Model M Interior.jpg (481.73 KiB) Viewed 6449 times

[Firebolt1914]

I'm planning on having a plate heat treated just for aesthetic purposes. Does anyone know more about this process?

[clickykeyboards]

One feature of many (but not all) early model M's from late 1985 and early 1986 is the thicker, curved steel plate.

In the majority of later model M keyboards (1987 - 1999), the curved plate appears a dull steel gray without any coating.
...but in some rare examples the additional coating on the thicker steel plates results in a fine, mirror-link finish.

1390120 chrome.jpg (73.72 KiB) Viewed 6423 times

1390120-chrome2.jpg (94.21 KiB) Viewed 6423 times

[E3E]

I'm planning on having a plate heat treated just for aesthetic purposes. Does anyone know more about this process?

Well, I can tell you that fresh new tips on my soldering iron develop this kind of multi-colored iridescent look after heating up for a while (around 300 c). I think you'd be able to find some tutorials online though, and I don't think it'd be hard to do, you just need to make sure you do it the right way.

http://www.instructables.com/id/How-to- ... with-HEAT/

Here's one!

It seems that the deliberate process is called "inco-coloring."

[emdude]

https://en.m.wikipedia.org/wiki/Chromat ... on_coating

Unfortunately this doesn't seem like something you can do at home..

However, hexavalent chromium is toxic, thus, highly regulated...

[E3E]

Oh, perhaps it is chromate conversion then! Still, I think a similar effect could be had through heat treating. Much less toxic too.

[tigpha]

http://www.instructables.com/id/How-to- ... with-HEAT/

Here's one!

It seems that the deliberate process is called "inco-coloring."

I would not recommend doing this on the zinc plated steel, and even less so on the chromated steel.

"Galvanized steel can be welded; however, one must exercise caution around the resulting toxic zinc fumes." Chromate conversion coating, in addition to chrome (toxic to kidney, liver and blood cells) also contains zinc (toxic fumes above) and potentially cadmium ("Inhalation of cadmium-containing fumes can result initially in metal fume fever but may progress to chemical pneumonitis, pulmonary edema, and death.") too. Definitely a toxic risk if the steel plate is vigorously heated over flame.

[emdude]

Oh wow, would that preclude even sanding down the plate? I also wonder about the newer plates, I've sanded those down to no ill effect.

[Chyros]

From what I understood, the rainbow effect comes from heat treatment, where the varying thickness of oxide layer creates a varying reflectance wavelength, resulting in different colours being shown, i.e. iridescence. Could be electroplating though, I wouldn't know for sure. Something I'd have to examine by EDX or XPS xD .

[tigpha]

Oh wow, would that preclude even sanding down the plate? I also wonder about the newer plates, I've sanded those down to no ill effect.

Hi Emdude,

I think that sanding should be relatively safe, as long as you don't ingest or breath in the dust. I'd recommend a dusk mask even when sanding down timber or plaster. Dust in the lungs is not good in any case. Simple guideline: if you smell something, you're likely breathing it in, so ventilate, and protect yourself with a face mask. I bought a 3M 4000 series organic vapour and dust mask for roughly £15-£20 a while back to handle solvent based paints. It served for years. It's a good investment.

Perhaps using it for years was not wise -- they have a limited shelf life -- but I didn't use it often at all, and very infrequently with solvents.

[tigpha]

From what I understood, the rainbow effect comes from heat treatment, where the varying thickness of oxide layer creates a varying reflectance wavelength, resulting in different colours being shown, i.e. iridescence. Could be electroplating though, I wouldn't know for sure. Something I'd have to examine by EDX or XPS xD .

The Wikipedia page may not be authoritative, but to a neophyte like me, it is instructive. There's a "black chromate" finish which I believe is the one I find in the IBM Bigfoots I have. It's certainly not black paint. The IBM PC-XT, made in the U.K. is painted, and comparison between the U.S. made and U.K. made plates shows that the paint does not last anywhere near as long as the black chromate-converted plates.

[emdude]

Oh wow, would that preclude even sanding down the plate? I also wonder about the newer plates, I've sanded those down to no ill effect.

Hi Emdude,

I think that sanding should be relatively safe, as long as you don't ingest or breath in the dust. I'd recommend a dusk mask even when sanding down timber or plaster. Dust in the lungs is not good in any case. Simple guideline: if you smell something, you're likely breathing it in, so ventilate, and protect yourself with a face mask. I bought a 3M 4000 series organic vapour and dust mask for roughly £15-£20 a while back to handle solvent based paints. It served for years. It's a good investment.

Perhaps using it for years was not wise -- they have a limited shelf life -- but I didn't use it often at all, and very infrequently with solvents.

Thanks for the advice! I suppose sanding down the rust will be all I can really do then.

[E3E]

Oh wow, would that preclude even sanding down the plate? I also wonder about the newer plates, I've sanded those down to no ill effect.

Hi Emdude,

I think that sanding should be relatively safe, as long as you don't ingest or breath in the dust. I'd recommend a dusk mask even when sanding down timber or plaster. Dust in the lungs is not good in any case. Simple guideline: if you smell something, you're likely breathing it in, so ventilate, and protect yourself with a face mask. I bought a 3M 4000 series organic vapour and dust mask for roughly £15-£20 a while back to handle solvent based paints. It served for years. It's a good investment.

Perhaps using it for years was not wise -- they have a limited shelf life -- but I didn't use it often at all, and very infrequently with solvents.

Thanks for the advice! I suppose sanding down the rust will be all I can really do then.

You can always paint it!

https://youtu.be/lbIAjPCz2nk?t=83



It's what I did for the back metal cover of my FAME keyboard and it's really beautiful.



Also painted the switch mounting plate blue (this is a translucent paint which shows the brushed finish beneath)!

You can do all sorts of things.

[emdude]

Wow, that looks fantastic. I probably will end up painting the steel plates in some way.

Also, off-topic but I noticed your Kirby toy, I have one too (somewhere..)!

[fohat]

I probably will end up painting the steel plates in some way.

If you are in the US, be sure to look into Rustoleum's new line of "hammered" metallic spray paint colors.

https://geekhack.org/index.php?topic=76 ... msg1900511

[E3E]

Wow, that looks fantastic. I probably will end up painting the steel plates in some way.

Also, off-topic but I noticed your Kirby toy, I have one too (somewhere..)!

Thanks, haha. I love Kirby! Have a bunch of them on my desk.

Adding to what fohat says, I used Rustoleum Colorshift in Galaxy Blue. It has to go over a black base coat, but it looks so good after about 3-5 coats.

To get that gleam, either use a clear coat or do some fine sanding up to a ridiculously high grade (tedious but the results are dazzling). I used clear coat on that one, but I recently sprayed some plates for a friend and polished the clear up to 14000 grit. Wish I had a bit higher of a grit, but it did look nice!

[emdude]

If you are in the US, be sure to look into Rustoleum's new line of "hammered" metallic spray paint colors.

https://geekhack.org/index.php?topic=76 ... msg1900511

Thanks, haha. I love Kirby! Have a bunch of them on my desk.

Adding to what fohat says, I used Rustoleum Colorshift in Galaxy Blue. It has to go over a black base coat, but it looks so good after about 3-5 coats.

To get that gleam, either use a clear coat or do some fine sanding up to a ridiculously high grade (tedious but the results are dazzling). I used clear coat on that one, but I recently sprayed some plates for a friend and polished the clear up to 14000 grit. Wish I had a bit higher of a grit, but it did look nice!

I am still relatively new to keyboard restoration; I actually have tried just Rustoleum clear enamel spray paint with decent success. Thanks for the suggestions, I will keep them in mind.

[tigpha]

Polishing the backing plate to a mirror finish, protected with a clear lacquer (maybe an epoxy two-part resin?), definitely looks like the best option to me.

For the IBM Model F, the perforated barrel plate may need to have the barrel holes cleaned from excess paint. Three coats of good quality paint (red oxide primer, undercoat, topcoat) tends to reduce the diameter of the hole, preventing the barrels from being inserted. The same applies for Cherry and ALPS mounting plates.

[phosphorglow]

Though I never went off and sanded down or polished the first generation style plates with that gorgeous plating, I did polish up quite a few of the later style galvanized plates in my early days of working on M's. And a number of plates with minimal rust spots were sanded down entirely, and then coated with a rust inhibitor. Which resulted in a bit of lost character and potentially making them less effective at combating ambient humidity or future spills. Time will tell.

I have dealt with some awful and nasty rusted plates (...which were gorgeous in all their glorious rust...) that I brought back using electrolysis and citric acid before painting. I even went so far as to try my hand at zinc electroplating at home, which was a neat experience. I've had one of those test plates hanging in a somewhat humid area for almost two years now with no ill effect.

In my earlier days I had a rather gung-ho approach in my pursuit of preservation, which evolved into a very minimalist approach: if it's pretty much fine, leave it be. All those lines and "imperfections" are beautiful in their own way. And no matter what galvanizing method they used, it's lasted this long and will continue to do so, barring a catastrophic liquid spill that doesn't get attended to.

So! In the minimalist approach to preserving the history and beauty of each individual plate, if there are just a few spots here and there you can take some sandpaper and work on those areas only, clean them up with some isopropyl alcohol, and then hit them with a paint pen in a similar color. Like touching up paint on a car - you don't sand the whole thing down to fix a few spots. Especially if the original vintage coat is pretty much fine.

The moral of the story:
The pursuit of preservation has the potential to become the opposite.
(Or, "the road to hell is paved with good intentions..."?)

My two cents, anyhoo.

I do love that the appreciation for their beauty has brought up the discussion though.

[emdude]

Really appreciate your input, your work on restoring Model Ms is really phenomenal and I admire the love and care you put into doing it.

At this point, I am pretty hesitant to touch the steel backplates of my older Model Ms as well and will probably leave them be for the time being. I don't mind sanding down the later galvanized plates though. I personally feel that nothing much is lost by doing so, but the early plates with that brilliant rainbow sheen? I am fairly certain that I won't touch those at all, short of catastrophic corrosion.

I definitely would like to attempt a zinc electroplating as you have, and/or a paint job like E3E's sometime in the future for ickier plates.

[fohat]

I agree with Phosphorglow on the M plates. I have been lucky in that most of the ones that I have dealt with have been reasonably clean and only minor touch-up was needed, at most.

F plates, on the other hand, and most vintage Alps plates have considerable rust and need sandpaper and paint.

As far as a few coats of paint constricting the inner diameter of openings, I do not look at this as a bad thing, since I want everything tight and try to reduce noise in whatever ways I can. If I can push them in, I do not worry that they are tight.

[berserkfan]

This will probably make me unpopular, but I have 'vandalized' many of my IBM backplates and covered that electroplating or whatever that is.

I live in a tropical country, so any scratches when bolt modding = avenue of future rust. Only practical solution at a modest and practical cost is to paint, so I do just that.