[TowerTalk] Very Old Grease Characteristics

Thu Dec 21 11:04:31 EST 2006

Finally, one I can help with!

Out here on the farm we see plugged up grease fittings all of the time.  In 
fact, when I bought my 65' bucket truck the turret was stuck.

There are a couple of things to try.  First, remove the zirk and dig out 
everything you can with a small screw driver or some such tool.  The grease 
will indeed get hard as the solvents in it evaporate.

Once you have the hole cleaned out as well as you can, put the zirk back in 
and grease the heck out of it.  Some of the new electric grease guns have 
much more power than you are likely to be able to create with a hand grease 
gun.

Usually, that'll kick things loose.  If not, open it back up, clean again 
and spray everything with a penetrating oil.  Marvel Mystery oil or some 
other favorite of yours.  On my bucket truck I used several different ones 
over about a month period before it finally broke loose.

You may want to use a very light grease for that first shot, just to make it 
a bit easier for it to force the new grease into any cracks in the old.

Also, if you can get a torch up there that'll help soften up the old grease. 
Just be careful you don't start anything on fire.  Note: if the housing is 
very thick at all you may need an oxy acetylene torch vs. a propane one.  At 
the very least, you'll probably need a MAP torch.  They burn much hotter 
than propane.  Be careful not to overdo the heat, don't want to get it all 
read hot then have something bend on ya.  It's amazing how much a bit of 
heat will often help in a case like this.

laters,
Marlon
(509) 982-2181                                   Equipment sales
(408) 907-6910 (Vonage)                    Consulting services
42846865 (icq)                                    And I run my own wisp!
64.146.146.12 (net meeting)
www.odessaoffice.com/wireless
www.odessaoffice.com/marlon/cam

----- Original Message ----- 
From: "John." <johne at tds.net>
To: "Pat Barthelow" <aa6eg at hotmail.com>
Cc: <towertalk at contesting.com>
Sent: Wednesday, December 20, 2006 7:46 PM
Subject: Re: [TowerTalk] Very Old Grease Characteristics

We in the past with similar type of assembly used a "Port a power"
hydraulic pump.
We removed the pushing piston from the hose end and used the hydraulic pump
end screwed  the hose into the threads of the removed grease Zerk.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_491_491

The idea is to use hydraulic   pressure from the port a power to loosen
the old grease .

You may also fill the hose with solvent, Then the "Port a power" will
push the solvent around the pin.

Be very carefull !~

de John KØCQW

Pat Barthelow wrote:

>Folks:
>
>We are stymied in our work to bring the Jamesburg 30 meter dish back into
>operation.  The dish is currently in the "stowed" position, pointing
>straight up.  It is locked in that position by a 3" diameter stainless 
>steel
>"pin" that is electrically driven up a cylinder, into a hole in the heavy
>steel elevation motion  system.
>
>See: http://www.longandflatsociety.com/Default.aspx?tabid=474
>
>The pin's  close fitting cylinder-housing has zerk fittings for heavy 
>grease
>liube that probably had not been attended to in years, possibly decades.
>The dish probably had not been the stow position for  decades, if ever, as,
>it sat pointed at an Intelsat geosynchronous satellte, low to the horizon,
>over the Pacific since 1968.   Two years ago, someone moved the dish to 
>stow
>position.  We, wanting to do moonbounce with the dish, have tried the two
>ways to retract the pin to unlock the vertical motion, using the locking 
>pin
>motor drive, and the manual  crank, with no luck. We have hand cranked the
>vertical motion support so as to remove any shear forces on the pin;  That
>is, the pin is precisely centered in the close fitting  hole.   The pin is
>so solidly stuck, it may as well have been epoxied into place.  Moderately
>powerful forces have been used to try to push the pin down out of the 
>locked
>postion. to no avail.
>Some of us think there may be wear ridges inside the cylinder preventing 
>pin
>movement downward.   The pin is in some ways similar to a piston,  has a
>connecting rod and wrist pin-like connection in its bottom for motorized
>retractor/inserter drive.
>We are going to investigate that for possible cylinder interference,  in
>detail our next visit.
>
>Others think that the 30 year old grease has fossilized to something akin 
>to
>epoxy, or coax seal,  and is keeping the pin from moving.
>
>My question is what does thick bearing grease evolve to in, say 30 years, 
>if
>untouched?   Stone?  Epoxy?   Grit?
>
>A parallel to normal towers might be a tower in decades long storage, that
>had heavy greased cable pulleys.  Has anyone found 30 year old pulleys to 
>be
>jammed up hard with what used to be lube grease?
>
>73, DX, de Pat AA6EG aa6eg at hotmail.com;
>Skype: Sparky599
>Moon or Bust!--Jamesburg Gang Rides Again!
>
>
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