What is the best fluid to restore a magnetic compass??ÿ
Thank you
Alcohol.
The main requirements are that it not freeze, should be inert chemically to the materials of the compass, and of a viscosity that is appropriate for damping the motion.
Google suggests alcohol, baby oil, or mineral spirits. Consider if there are any plastic parts or paint that a fluid might attack.
I bet each manufacturer has a proprietary concoction on which they rely.?ÿ Methanol and ethanol are a big part of it for sure to keep the freezing in check.?ÿ I have an old survey manual that mentions mineral spirits (turpentine?) as an admixture to alcohol.?ÿ A glycol is common to keep UV from breaking down the organic compounds.?ÿ The type of "glass" also has a lot to do with the mixture.
Try tequila.?ÿ Keep a bottle around for emergencies.?ÿ ;)?ÿ ?ÿ?ÿ
CCL4
?ÿ
Worked awesome.
Kinda toxic.
?ÿ
?ÿ
I found a bottle of carbon-tet in the garage; a brown glass pint bottle with a "Humco" label.?ÿ The contents had apparently evaporated.?ÿ It was in the garage when I bought the place years ago.?ÿ I think I kept it because it looked cool..a bad habit of mine.?ÿ 😉
Years ago I did a lot of work for various phone companies.?ÿ When I wasn't surveying I was usually working on some maintenance or records that involved the switching equipment at the central office, or what we called "wire centers".
Back in the day all the switching was mechanical and done with relays as opposed to modern digital equipment.?ÿ The noise inside a wire center during a business day could get deafening with all the clatter of these relays.?ÿ
The critical contacts on these relays were made of gold so they wouldn't rust.?ÿ But over a period of time minute DC sparking would create a residue, not from the gold actually but from the spark generated oxidation of small particles of dust in the air.?ÿ Cleaning the contacts was a time consuming job that required a Q-tip and a solvent...and there were literally millions of contacts in any wire center.
Lots of different solvents were tried but they all had drawbacks.?ÿ One became so well used the company bought it in bulk: ethanol.?ÿ It came in quart bottles labeled "Everclear".?ÿ Yup, grain alcohol from the liquor store.?ÿ It worked great and evaporated quickly.?ÿ But this was boxed differently than the stuff from the packy.
In Oklahoma consumable alcohol must pay a tax to be sold and bear a tax stamp.?ÿ Since the phone company wasn't drinking the stuff they avoided paying the tax.?ÿ But the cardboard boxes they were shipped in had a label across the top that read "NOT FOR HUMAN CONSUMPTION"...right...
There was always a dozen cases or more of Everclear in the stockroom of any wire center.?ÿ Nobody ever wanted the tedious task of cleaning contacts.?ÿ But usually starting around Thanksgiving with a crescendo at New Years the bottles would start disappearing.?ÿ By January 2nd.?ÿ someone had to order more "solvent".
With a gleam in his eye one supervisor quipped, "we always clean up the contacts real good before the first of the year".?ÿ
@paden-cash Was this a step-by-step / Strowger office? Those were cool and fascinating in a loud, clunky way.
A lot of them were old SXS offices.?ÿ Most were a little newer crossbar apparatus.?ÿ I was always told Bell Systems (our main client) preferred the crossbar over the old "step" equipment because of patent ownership.
A little later we worked on hundreds of retrofits on small rural "mom & pop" phone companies that Bell was buying up.?ÿ That's where I saw a lot of the really old step equipment.?ÿ Some still had the older rotary "agitator".?ÿ All of that old equipment was bought up by salvage companies.?ÿ I heard a few of them were sent to Central America and reassembled.?ÿ
Funny story about "step" equipment.?ÿ And yes they could get loud.?ÿ We were in a small town in OK (population about 250) doing "records check".?ÿ We would take their cable/ phone number records and verify them on the main frame.?ÿ Relatively simple, you just took your headset (we called them "Buttinskis") with their tip and ring needle and run down the cable terminations on the frame.?ÿ A good number had "battery" verified by a dial tone. One guy on the terminals and another guy with a clipboard and you were set for hours.?ÿ Special circuits and dedicated lines were always marked with red buss buttons instead of black.?ÿ We always stayed away from those.?ÿ
We always worked at night to avoid disruptions and the noise.?ÿ This fit well with six or eight guys living in hotel rooms.?ÿ Late one night we were toiling away.?ÿ The only thing you hear was an occasional?ÿnumber being dialed.?ÿ Very little noise except the cooling fans on the power equipment.?ÿ?ÿ
Suddenly the equipment came alive.?ÿ You couldn't hear yourself think with all the relay chatter.?ÿ Now this was 2 in the morning in a farming community of 200 people.?ÿ We couldn't figure out what was going on.?ÿ Someone started pounding on the back door.?ÿ It was the mayor and the police chief.?ÿ When we opened the door we could hear the tornado siren blaring..and it was a calm clear night.
One of us had shorted out the dedicated line from the cop shop to the emergency siren.?ÿ Once we figured out where it was it was shut off.?ÿ I guess everybody had woke up and was trying to figure out where the tornado was at.
In our defense the circuit had been "thrown" to a different location on the mainframe and it still had black buss buttons on the connection instead of the appropriate red ones.?ÿ The mayor was still pissed at us because he had to get out of bed.
?ÿ
@paden-cash Cool story! And about crossbar, along with the patent issues crossbar must have required way less maintenance than SXS did. Also, it could provide features that SXS couldn't, and should have taken up less space in all but perhaps the smallest installations. It was neat, though, how SXS completed the call the instant that final digit was finished dialing.
My main job back then was outside plant.?ÿ But inside plant was so much more fascinating.?ÿ I've seen old SXS centers that looked like museums with floors clean enough to eat on.?ÿ There was lots of clean oiled bumpers, polished brass and laced copper conductors.?ÿ Some of those places were showcases.?ÿ Some of them were held together with tape and chicken wire too.
?ÿ
What is the best fluid to restore a magnetic compass??ÿ
Thank you
I've maintained compasses on sailboats for 45 years now and it depends.?ÿ Mineral oil and alcohol seem to be the two choices, with mineral oil used in large lightly damped compasses & alcohol used in smaller compasses with a lot of damping from the card shape.?ÿ Best is to contact the manufacturer but Isopar-L is the go to fluid for mineral oil compasses;?ÿ I don't know about alcohol compasses because the 4 or so I own haven't leaked but they're just 2" compasses where the globe is sealed and I'd assume you just throw them away if they fail.?ÿ
OTOH if you have an $800 Danforth ship's compass best is to have it repaired which will seal the leak(s) and make it as new for only a few hundred bucks.?ÿ If you're in fix it or break it mode you can easily determine what the fluid is by a sniff, rub on your fingers and taste test.
I think I kept it because it looked cool..a bad habit of mine
Your should see my garage right now.?ÿ I bought a bunch of machine tool accessories at an auction, planning to keep one piece that I want (a rotary table for my mill) and sell the rest to pay for it, but as I go through the stuff I'm having to fight the desire to keep more of it.?ÿ In the mean time I'm having to step carefully around all the items spread out all over the floor.
The question is what was the original?
oil replaced, alcohol replaces alcohol.?ÿ
oil seals with alcohol (vice versa) gonna cause problems.?ÿ
I have a ships compass that??s now a display compass. It??s was cleaned up and left dry. For display that??s fine and it still works really well without fluid. I wouldn??t take it on a field trip, but it gets used.?ÿ
"The main requirements are that it not freeze, should be inert chemically to the materials of the compass, and of a viscosity that is appropriate for damping the motion."
?ÿI dismantled the compass today and found that it was in worse shape than I thought. There was some kind of white coating, maybe cellulose or some kind of plastic, on the inside of the case that had been deteriorating. The fluid in the compass was apparently alcohol, and it apparently caused the white substance to disintegrate into a gooey mess, which prevented?ÿthe card from turning freely. Also, one of the magnets had come loose from the bottom of the card.
I cleaned it with mineral spirits. It took over an hour to get most of the white coating off. Then, I noticed that the numbers on the card had deteriorated; the card didn't agree with the mineral spirits, unfortunately.
So now I lack a card.
?ÿ
?ÿ
?ÿ
