[Milsurplus] Rusted parts help?

[Bob Camp]

Hi

If you can get the mechanism torn down far enough to put the shafts in an ultrasonic cleaner that can do wonders. You do *not* want to put everything and anything in one. Put in the shaft and the solvent of your choice and let it run for a while. Cycle between 10 minute off periods and maybe a minute or two of on time. Some of the more affordable ultrasonic cleaners are not happy running for a few hours at a time. Continue the process for a couple of days. The ultrasonic is about as good as you can get at driving solvent into small spaces. By it’s self it’s not magic, you still need a good light penetrating oil to do the job on the rust. 

If when looking at the real assembly this simply isn’t possible, don’t try half measures. Unless you can immerse the whole object it’s not worth trying. Certainly do not immerse anything that remotely looks like plastic...

Bob

On Jun 6, 2014, at 2:21 PM, hwhall at compuserve.com wrote:

> One of the WWII restoration projects at the museum is a bunch of large impulse driven (slave) clocks we wish to return to operation (I've gotten a couple running so far) . The problem we have that I hope you all can help solve is that many of the concentric shafts for the minute hand and hour hand are seized (i.e., solid minute hand shaft inside tubular hour shaft). The shafts are concentric for about two inches length, with about 3/8 inch overall outside dia. The two shafts were a very close fit originally and are now pretty solidly stuck.
> 
> I've tried Liquid Wrench but it doesn't seem to be able to penetrate. I've tried placing the assembly in my zero-deg freezer for a couple days & then hitting the outer hour shaft with a propane flame for several seconds, then tapping on the inner shaft. So far, nothing gives. I can't hammer very hard, the rest of the assembly won't take the abuse.
> 
> Is there something that penetrates better than Liquid Wrench? If no, then I think my next attack will require packing one end of the inner shaft in dry ice with the flame applied to the outer shaft, in the hope that the reason it failed before was the inner took heat from the outer too quickly. 
> 
> Any other ideas??
> 
> Thanks!
> 
> Wayne
> WB4OGM
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html