Minute cracks key caps

[Tonewheel]

This may have been covered elsewhere. My unit's key caps have very fine cracks top and front on quite a number of keys. Anybody out there found a fix that does not do more harm than good? Is it better just to consider these beautiful, like wrinkles? BTW, wrinkles don't hurt, I have found, thank goodness. Everything else does

[velo-hobo]

Personally I wouldn't even bother, to me they are part of the vintage character of these instruments, and unique to each individual instrument. Kind of like finish checking of a very old guitar or bass. Or as you suggest, wrinkles (aka the accumulated markings of earned wisdom...)

It is amazing to me that this ~60 year old plastic holds up as well as it does. "Erasing" these cracks seems quite obsessive unless you are attempting to restore an instrument to factory mint, in which case you may be better off replacing all of the key tops and fronts with new material.

I have a 720 that suffered a badly chipped front edge of a key top due to an unfortunate incident, and was fortunately able to swap out the keycap for a good one I nicked off a 206 I keep around for parts. It's not an exact color match nor edge profile match, but it's not terrible, though I wish it had never happened at all. Oh well! It's not like my 720 is aesthetically minty, anyway. Character, and part of the story of this particular instrument.

Back on the technical side of the question, I'm not certain of a reliable method to suggest for all cases. Relatively shallow scratches or cracks can potentially be buffed out, which I have done - although at potential cost of color mismatch since you might buff through age-discolored surface to fresh material. Best to look at the back edge of the key cap where it sits underneath the lid/felt and assess how discolored it has become over time.

You could attempt to fill a deeper crack with say, baking soda and superglue (this is a luthier's trick for building up a too-deep slot in the nut of a guitar) but this method would probably look far worse than just leaving it alone. Deeper scratches and cracks are likely filled with dirt, and again there are color-matching concerns for more aggressive sanding/buffing.

If you've ever seen touch-up paint on an old car or bicycle, you might agree it looks worse than had it been left alone, and there are no significant functional issues to consider as with a vehicle, such as inhibiting rust formation.

If this is a stage instrument, nobody in the audience will likely ever notice it.

[Alan Lenhoff]

You've not described the cracks in detail. But I'm guessing these are typical hairline cracks that are caused by the aging of certain plastics. I had a 200A with about 10 keys like this. Even though the cracks were so minor that they could not be felt, they went too deep to sand out. I found a tech with a parts piano who removed some original keytops, which I used to replace the bad ones on my piano. This worked fine, but the "new" keytops did not match the yellowing of my other keys. So, I sanded and buffed all the keys to make them all the same color.  The results were excellent.  But it was a lot of work!

I have a Minimoog with several keys like this. After my experience with the 200A, I've decided (as Velo-Hobo suggested) to accept them as part of the vintage character of the instrument.

Alan

[Tonewheel]

The attached image above is representative and is hairline. I think that you are all correct. If there is no simple solution that works well, I'll just leave this as is.

I like playing this keyboard more than my Rhodes because of the ease of action and responsive bark, not withstanding the "miracle bump" I did several years ago to ease the action on the Rhodes.

I have left the top open for years because of my need to keep tweaking things. And that's because it is rewarding. The benefit of analog. The stuck key is now resolved. The out of tune tines are in tune. I have gone from a blackfaced Twin Reverb to an acoustic amp to an old Yamaha solid amp, and I like the last best.

I did buy a new Warneck Research EP-200A Amplifier that I will have a tech install, and I am hoping for a quieter signal, and maybe some surprising tonal improvements.

Then I might just close it up.

Thanks for the helpful comments. 

This is a recent iPhone recording. Dry. Vcaroo upload

[Alan Lenhoff]

Your Wurli sounds quite nice.  You will not regret buying the Warneck amp.  Tim Warneck is an amazingly talented electrical engineer and musician, and a great guy, too. His amp is VERY impressive -- and VERY quiet. 

Alan

[velo-hobo]

Hey, also want to say it sounds really nice. For a 200A, on this recording it really has a nice throaty tone that's almost akin to that of a 140 or 120 series.

You'll love the Warneck amp. I installed one of those for a client and was very impressed with all aspects of its design and sound, and I also had a good experience communicating with the product engineering and sales folks there. They were really helpful in sorting out some questions I had for my particular application.