[GreenKeys] cleaning 28ASR keys

[Kevin H. Phillips]

I know that others who have worked with these machines have encountered 
similar problems but I can't remember the exact products used to clean 
the keys and thought I would post about something I "discovered" while 
working on the machine I picked up a few weeks ago in Houston, TX.


The keys tops, the plastic sleeves covering some of the internal wiring 
harness, and other things were coated with a white "mold" or something.  
In addition, the keys also seemed to have an "undercoat" of something 
brown.  I speculated that it could have been tar and nicotine from the 
machine having been in an environment for a long time where there was 
heavy cigarette smoke in the air but I don't know if that is possible.  
It was almost like varnish.


The Space key on this machine was repeatedly sticking and there were 
problems with inserting random LF at times when I was punching a tape.  
None of that was cured by localized lubrication on the spots I could 
reach inside on the transmitter base.  I finally decided to remove the 
keyboard cover to try cleaning/re-lubricating the Space bar mechanism at 
the very least.  Once I saw the full condition of the key tops, I 
decided to proceed with a full cleaning of the keys.  I also decided 
that I would clean them one-by-one to avoid any confusion.


I flushed the mechanism/springs with degreaser followed by a water rinse 
and then dried the mechanism with a heat gun.  I tried cleaning the key 
tops with my old reliable, Simple Green, and even 409, but not even that 
was completely removing the brown residue. I was afraid to leave 
anything soaking in Simple Green for very long.  I tried some other 
cleaning products at hand but nothing helped much.


Then I found an aerosol can of an automotive product I bought several 
years ago being sold at a local fuel station ostensibly for charity.  I 
had not paid much attention to the product.  It sprays out to create a 
soupy foam.  The product was labeled "Cleaning Wax" and is by Fast Wax 
(www.fastwax.com).  I do not see the exact product listed now on their 
website but perhaps the "General Cleaner" is the same.  I started by 
spraying a shallow puddle of this stuff in a bowl and letting the key 
top sit for a few minutes before rubbing it with a cloth.  Most of the 
residue from the key top disappeared easily.  Even the metal stud was 
clean.  But, there would occasionally be some brown residue left. This 
sometimes could be removed with applying a lot of "elbow grease" but I 
also found if I soaked the key top again or let it sit in the cleaner 
longer that the residue would be completely removed.  I just left one 
key top sitting in the stuff overnight and it came completely clean with 
no effort.  This obviously will take a long time doing this one at a 
time but I am not willing to risk mixing up the keys!  Attached are some 
"before and after" pictures of one of the worst key tops.  I have about 
one-third to one-half of the key tops cleaned at this point.  I am 
oiling the pivot points as I re-attach the key tops.


73


Kevin

W5TTY





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