[R-390] More geartrain rebuild info

[Bob Camp]

Hi

If you do decide to go the dishwasher route be *very* careful to tie 
down the parts you are trying to clean. At least around here destroying 
the dishwasher by getting a gear stuck in the impeller would not 
enhance the reputation of the boat anchor effort ....

As long as we are on exotic cleaning methods here's one that has not 
come up recently. Reasonable sized industrial ultrasonic cleaners show 
up surplus from time to time. The ones I would watch for are made by 
Crest Ultrasonics. They are a bit higher power than the hobby cleaners 
out there and are designed for 24/7 use. Even a fairly small one is 
plenty big enough to fit R-390 gears into. Since they are stainless 
steel you can use almost any solvent or cleaner in them. An over night 
run should do wonders ....

If you are going to keep the gear halves together during cleaning then 
I suspect the only way to get the stuff out from between the gears is 
some kind of long soak ...

Something that the industrial cleaning gear does is to re-distill the 
solvent. This lets you get a lot more miles out of a gallon of stuff. 
Might be a use for that moonshine setup out behind the barn ....

Regardless of how you do the cleaning a good drying process is 
important. The family oven could be used, but a $3 garage sale toaster 
oven probably makes a bit more sense. You want to get the metal parts 
up to about 250F for 15 minutes or so to be sure you have driven off 
all the water or solvent.  Going a whole lot above this temperature 
doesn't do a lot of good and you may start to affect the parts. Another 
nice way to do this is with a surplus lab oven, provided you can pick 
one up cheap.

The need for drying the parts is debatable, but I think it's well worth 
it if you are using soap and water. Even with solvents you can get some 
odd  results from small amounts of solvent mixing with lubricant. Air 
blow off is another alternative and it works, it's just a bit exciting 
when that little spring slips and now is *somewhere* over on the other 
side of the room ...

	Take Care

		Bob Camp
		KB8TQ


On Feb 26, 2005, at 9:25 AM, Barry Hauser wrote:

> Hi Barry & gang:
>
> Sometimes, the thing to try if petroleum based solvents and/or 
> trichloroethylene don't work is hot soapy water -- or very hot water 
> itself.
>
> The kerosene or denatured alchohol will get some of it, but the 
> hardened stuff may need some heat.  If detergent doesn't work, try 
> mild bar soap --  old fashioned stearate-based soap, like Ivory.  You 
> might still need to use an old toothbrush or nylon auto detailing 
> brush -- or that electric toothbrush that needs a new brush end 
> anyway.
>
> Another idea -- one of those small steam cleaners -- if you already 
> have one.  If you're in a hurry, an "As seen on TV" version can be 
> bought at places like Walgreens. (They still steam-clean car engines, 
> don't they?) Might work, and they're fairly cheap.
>
> Some have reported good results with the dishwasher -- that means 
> super hot water and maybe some dishwashing detergent too.  I haven't 
> yet been so bold, but I have been surprised from time to time, after 
> struggling with one aggressive chemical after another, that hot soapy 
> water cleaned something up right away.  Of course, the part was 
> ususally hit with a few different solvents first, so may be a combined 
> effect.
>
> Barry
>
>
> ----- Original Message ----- From: "Barry" <n4buq at aol.com>
> To: "R-390 HF Receiver List" <r-390 at mailman.qth.net>
> Sent: Friday, February 25, 2005 9:30 AM
> Subject: Re: [R-390] More geartrain rebuild info
>
>
>> This geartrain was just a tad dirtier than my first one, but not by 
>> much. I
>> did not tear down the first one because I had no instructions for 
>> putting it
>> back together.  Now that I've done the complete teardown on this one 
>> and
>> found what I have found, once I get this radio finished, I'm probably 
>> going
>> to tear down my first one and do a complete cleanup on it too.
>>
>> After taking all the gears off, I took the cam/frame assembly to the
>> automotive shop here at work and washed it in one of their parts 
>> cleaning
>> tanks.  It didn't really do much to cut the dried grease.  I tried 
>> denatured
>> alchohol with not much better results and am now using kerosene.  
>> That works
>> a little better than the other things I've tried, but it doesn't 
>> really
>> dissolve the dried grease without a lot of rubbing either.  While it 
>> might
>> work better, I really don't want to have an open container of 
>> gasoline. Any
>> other good solvents?  Brake Cleaner?  Carb Cleaner?  Fire?
>>
>> Barry(III) - N4BUQ
>>
>
>
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