IBM Model M Internals cleaning/moding tips?

[IonutZ]

So I finally took this filthy Model M that I got apart (my first one in 2 decades) and the plastic plate seems to be broken a couple of inches in... the rubber layer is filthy, and there's rust over the actual metal layer...

So far I've cleaned every key cap by hand and I've cleaned the outer plastic layers but someone decided to write with blue pen on the top of the plastic casing and I can't seem to be able to take that off.

In order to take the rust off the steel plate I'm going to use some vinegar or baking soda and sand that off.

I'm wondering how I can clean the internals:

What's ok to use on the rubber layer?
What's ok to use on the actual membrane? (the one with the leads)

When I have these cleaned up I'm gonna perform the bolt mod.

I also plan on spray painting the M black, changing the green LEDs to blue and gifting it to my dad (after I acquire some black caps with white writing from Unicomp :3). Any suggestions on good spray paint for plastic?


By the way: I'm getting 6 Model M/Lexmarks tomorrow from someone on Craigslist, might let go of a few if you guys are interested. Will post pictures up tomorrow.

[snoopy]

I don't know much about cleaning that internals, but I know that you can't buy black caps with white letters from unicomp. You can only buy blank blacks from them. Maybe that's good to know before you paint it black

[Muirium]

The crack in the plastic plate (the "barrel plate" I presume: the one with all the cylinders on it where the buckling springs live) is bad news. Post a picture of the crack location, would you? If it runs through any barrels, they're most likely toast. And if it runs between barrels, that whole section of the keyboard probably won't ever feel right.

Still, it's good to have some really messy bits. You can experiment with strong cleaning techniques on them, so you know what it's actually wise to use on your incoming batch of hopefully cleaner keyboards!

[IonutZ]

How would one go about printing key caps haha does anyone doe that? I'll show the crack later today when I get a chance to take a picture... it's pretty nasty, right in the middle of one of the channels (I saw someone had actually used the plastic cement to fix one and said it was pretty stable).

[Peter]

the rubber layer is filthy

That caught my attention !
Exactly what 'rubber-layer' do you mean ?
Because 'normal' Model M's don't have it !

[Game Theory]

He means the membrane.

[Peter]

He means the membrane.

OK, that makes sense

[Muirium]

There is a soft rubbery layer besides the membrane films, in fact. Right above them, directly beneath the springs/hammers.

That's the part I have submerged in coffee, to treat the stink.

[Findecanor]

I saw someone had actually used the plastic cement to fix one and said it was pretty stable.

What you need is a kind of liquid plastic that adds bulk, as well as welds or adheres with the ABS in the barrel plate. Just a glue won't cut it. There are products called "poly cement" that are not much more than solvent - it will just eat the plastic and then dissipate, without connecting the two parts. I know, because I have tried that on a broken barrel plate.
I have heard good things about "Devcon Plastic Welder", but I think it might only be available in the US.
ABS dissolved in acetone might work, but can be quite messy to work with. I have considered epoxy.

Edit: "dissolve" -> "dissipate". Error. Sorry.

[webwit]

Epoxy works very well.

[Game Theory]

There is a soft rubbery layer besides the membrane films, in fact. Right above them, directly beneath the springs/hammers.
That's the part I have submerged in coffee, to treat the stink.

I stand corrected. I haven't fully disassembled my model M.

[IonutZ]

webwit just bought epoxy earlier, I bathed the frame (with the cylinders), the membrane films and the rubbery layer over night in water... washed it, and dried it, everything seems to be alright, it took the bath well... as for the stink, I ran a tissue with rubbing alcohol on the rubber layer, seems to have gotten rid of the initial smell, now it just smells like old rubber.

As soon as the frame dries up in a couple of hours, I'm going to use the epoxy I bought from ACE Hardware to fill the channels and leave it for about 20 hours before I drill the holes for the nut/bolt mod.

It seems I can't get printed black key caps so I'm just going to spray paint the thing either beige, creme, or white (don't know if there's a difference between beige and creme haha I suppose we'll find out tomorrow). I'm still swapping out those green LEDs for blue ones, just cause. IBM.

Got another 6 Model Ms, 3 with detachable cables, 3 with non-detachable cables. Is there any difference between those two models? I haven't really looked in depth at them, I haven't had any time... they seem pretty dirty... one of the ones with the non-detachable cables has its cable cut off, will have to use another PS/2 cable

AND I got a top and bottom empty case as an extra... seems like reconditioning Model Ms is gonna be my pastime for a while lol

[bitslasher]

Go back to ace and get this paint, "ACE Rust Stop - Machine and Implement - Ford Gray Gloss". It is a near perfect match for the industrial grey. It's not "silver" or "metallic" like almost all the gray paint I've found, it has the same tone as the industrial M, just not as "olive".

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[IonutZ]

So I ran into a bit of a problem... Both my ALT keys, PrtScr and Scroll Lock aren't working... for no apparent reason. Do they share a pin maybe?

[E TwentyNine]

They do. The enter key on your numpad is nonfunctional as well?

[IonutZ]

No... from what I recall from yesterday everything worked except...