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
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.
(509) 982-2181 Equipment sales
(408) 907-6910 (Vonage) Consulting services
42846865 (icq) And I run my own wisp!
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----- Original Message -----
From: "John." <firstname.lastname@example.org>
To: "Pat Barthelow" <email@example.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"
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.
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:
>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
>"pin" that is electrically driven up a cylinder, into a hole in the heavy
>steel elevation motion system.
>The pin's close fitting cylinder-housing has zerk fittings for heavy
>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
>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
>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
>postion. to no avail.
>Some of us think there may be wear ridges inside the cylinder preventing
>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
>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
>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,
>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
>jammed up hard with what used to be lube grease?
>73, DX, de Pat AA6EG firstname.lastname@example.org;
>Moon or Bust!--Jamesburg Gang Rides Again!
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