deskthority

One of the joys of this hobby is using new techniques to repair errors made in years past. Today I did just this while discovering a new technique!

A while ago I bleached a keyboard that I really like and left it worse for the wear. In particular, some key caps were quite bleached. You can see more details here:

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But then, I realized, this must just be a surface issue! Moreover - these are double shot ABS plastic caps, at least 1.5mm thick! I've got some room to work here.

So, I did some experimentation, and found that a moderate grit of sandpaper - 320 grit - was effective in removing the top layer of bleached plastic crud. But, this left the key cap in need of a good polishing. What to do now?

I knew that I had polishing wheels for my rotary tool ("Dremel") somewhere but after five minutes of searching I was fed up. So I worked backwards and thought, what could I use for polishing with readily available household materials? I decided to cut a Q-tip cotton swab in half, stick it into my rotary tool's collet, and use a polishing compound. I was unable to find my compound, so, I decided to give toothpaste a try since some people use this for restoring car headlights. The speed was just off of low - maybe about 15,000 RPM.
The results were better than expected! The technique can certainly use some refinement but things got better! I treated the Q, ><, R, and XMIT keys with this and they are at least looking better than they were before.
It's dead simple. 320-grit sandpaper, rotary tool with collet, cotton swab, scissors (to cut the swab), toothpaste. It works really well! It leaves the key cap with a satin finish, which is nice for giving some new texture to a well worn key cap. The resulting finish is smoother and more even that using a green Scotch-Brite abrasive pad, without gouging, but not nearly a full gloss. (I would test this on the far facing side of a key cap or on a spare key cap to see for yourself just what the effect is.)

Generally, 320 is pretty heavy duty. You can see the grain tracks in that red cap. You probably want to go with 800 to 1000 and then follow up with 2000 for a satin finish. Toothpaste on a 2000 satin finish will get you a mirror polish with just rubbing a small amount with a paper towel. Your flesh pressing against it will conform to the surface better than a wheel or block solution.

Unfortunately, this destroys all the original texture on the keycaps. It wasn't a problem with a couple of my projects since they were polished sphericals in the first place but definitely would do a number on these. I guess that's the tradeoff though to get deep enough to get under the bleaching.

Thanks! There is a lot to be done here. Mostly I thought it was a cute idea to put a Q tip into a Dremel.

I'd say sandblasting would be the only way to get something similar to the original texture. I definitely have felt the pain of blanched caps before though. Nefarious white outer layer usurping the original vibrant color. Tis a shame.

I've got a friend with a blaster that I'm hoping can fix some of the keys that have seen the worst of this.

XMIT wrote: Thanks! There is a lot to be done here. Mostly I thought it was a cute idea to put a Q tip into a Dremel.

Haha, right? Gotta love improvisation, but just don't clean your ears with it.

E3E wrote: I'd say sandblasting would be the only way to get something similar to the original texture. I definitely have felt the pain of blanched caps before though. Nefarious white outer layer usurping the original vibrant color. Tis a shame.

I've got a friend with a blaster that I'm hoping can fix some of the keys that have seen the worst of this.

Yeah there was a post about sandblasting here a while ago. I've got access to one too, I should try it out!