[R-390] Cleaning Gears & Cams

[ToddRoberts2001 at aol.com]

In a message dated 11/19/2005 12:05:55 PM Eastern Standard Time, 
chacuff at cableone.net writes:
Ultrasonic cleaning is a good way to go if you have one big enough to fit 
something as large as the gear train in.  I wish I did....
I guess it gets the gunk in between the split gears..have you ever pulled a 
pair apart after a cleaning to see what is left between them?
Cecil

I have been doing some research on ultrasonic cleaners. It seems they can 
damage aluminum parts in a process called "embrittlement". A standard test for 
ultrasonic cleaners is to immerse a piece of aluminum foil in the tank for a few 
minutes - the foil will be peppered with pin-prick holes that were blasted 
into the aluminum. If you leave the aluminum foil in the tank for 30 minutes it 
will be pulverized. Also have read it will strip the anodizing right off of 
aluminum. Supposed to be okay for steel parts though. Also read that ultrasonic 
cleaners will dull threads and dull the edges of sharp tools like scissors. 
Not sure if it's worth the risk? Maybe safe if used for just a few minutes? 
Sounds like a great way to clean an R-390A geartrain but don't want to risk 
damaging parts. Guess I will stick with using a kerosene soak and bath for now until 
I know more. 73 Todd - WD4NGG