Does anyone have a successful method?
I moved my late dad's mercury barometer (a 25 year service award from the farm he worked on) prior to decorating the room that it was in. For unknown reasons a bubble has appeared in the mercury, and in trying to get rid of it, there are now several bubbles. D'oh!
It's a single column of mercury, with a reservoir bowl at the bottom.
It's really quite precious to the family and before I resort to getting an expert into fix it, I would like to have a go myself.
I am aware of the health risks of mercury, btw.
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try moving a magnet up and down the scale and pulling all the mercury into the bulb area.
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The centrifugal effect works most times. Hold it at the non bulb end and then swing it in a smooth arc with no jerk at the end.
(no BBD not that)
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>> The centrifugal effect works most times.
Perhaps I should have mentioned this one is too long to swing about.
It looks something like this.
www.vanleestantiques.com/object.php?id=501
The type that holds a column of mercury that's approx 760 mm long.
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That is a very nice instrument.I would take it to someone in the know.
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My eldest son has my great grandfathers Barometer small round job.Over hundred years old.Just of the subject.
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Of course its not too long to swing about, how long do you think a golf club is? A golf swing is perfect for the job as its smooth. As is a hammer throwers movement.
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...Of course its not too long to swing about...
Go to the fair or playground and sit on a ride which goes round and round while holding the barometer pointed outwards.
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>try moving a magnet up and down the scale and pulling all the mercury into the bulb area.
Mercury is non-magnetic.
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Liquid metals have diamagnetism: so a current could be induced. en.wikipedia.org/wiki/Diamagnetism
Even better at 4k!
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Unfortunately you need to take the barometer to a specialist to be re-filled. Don't swing the barometer about - you may drop the thing and break the glass as then you will have a problem cleaning up the mercury which as you know is toxic.
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Google for "Removing an air bubble from a mercury barometer".
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Dutchie >> I would take it to someone in the know.
CGNorwich >> you need to take the barometer to a specialist to be re-filled.
That's what I now intend to do.
£200 I've been quoted so far from one jeweller though. Like most things that need to be repaired - it's a dying art. Either the people who used to do it have retired, died from mecury poisoning, or AN Other. I will need to shop round and hopefully find an independant enthusiast who does things like this as a hobby rather than a shop who have a big mark up.
Zero >> Of course its not too long to swing about
No offence Z, but I've already spilt a very small amount of mercury, I have no intention of swinging a delicate glass tube around and risk a large spill of mercury.
L'escargot >> Google for "Removing an air bubble from a mercury barometer".
Already done that and tried the suggestions found. i.e. gently tapping the glass tube with a finger nail. Another suggestion was centrafugal force - er, no thanks. Warming it, but risk breaking the tube if you get it too hot or the mercury rises too far.
From what 2 experts have said, the mercury has probably oxidised and wants draining, the glass tube cleaning inside, then cleaning the mercury and re-filling. Part of the reason for the air bubbles is a dirty tube not allowing the mercury to cling to the sides anymore.
It's 30 years old, the wood has a couple of blemishes on it, and one of the fixing clamps has broken. I guess I'll just have to bite the bullet, and pay for it to be restored to its former glory.
Thanks for all your suggestions so far though.
Last edited by: VxFan on Fri 8 Jun 12 at 16:52
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>> No offence Z, but I've already spilt a very small amount of mercury, I have
>> no intention of swinging a delicate glass tube around and risk a large spill of
>> mercury.
Crap swing huh? How about you and I play 18 holes, fiver a hole?
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>> Crap swing huh? How about you and I play 18 holes, fiver a hole?
Only golf I've ever played is the crazy type at the local park so you'd beat me hands down - unless it was a game of skill where you have to loop the loop, go over a moving drawbridge, and into the castles front room window while the curtains are still open.
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Oxidised mercury is a solid, SFAIK! Perhaps chill/freeze the base to get the mercury back into the base bulb.
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>>£200 I've been quoted so far from one jeweller though. Like most things that need to be repaired - it's a dying art. Either the people who used to do it have retired, died from mecury poisoning<<
Or gorn mad (as a Hatter)
Y'all need to find a little man out in the Shires somewhere who know's what he is doing and still dabbles with these devious devices out in his shed, who'll be overjoyed to relieve you of 50 squids for draining/refilling the critter.
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I am somewhat bemused by several references to a 'Bulb' at the bottom. We are talking about a Mercury Stick Barometer, which, if my understanding of Torricelli is correct, needs to have an open reservoir to work correctly. ANY air at the top of the stick will result in incorrect readings. Trying to get my head around how you can fill one of these with mercury.
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"I am somewhat bemused by several references to a 'Bulb' at the bottom. We are talking about a Mercury Stick Barometer, which, if my understanding of Torricelli is correct, needs to have an open reservoir to work correctly."
Will most likely be a Kew pattern ( if no adjusting screw on the cistern) or a Fortin type if there is such a screw.
www.russell-scientific.co.uk/article/KewBarometers
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This is the description by the OP: "It's a single column of mercury, with a reservoir bowl at the bottom." Is that a "mercury stick barometer? Or am I on a different page as it were?
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Yes that's a mercury stick barometer, Fortin and Kew pattern are variations in design.
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Thanks CGN. Now I know what to look for as an appreciating asset if we vcan get one at a sensible price!
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To me a bulb is sealed ( like a thermometer) - a bowl is open reservoir......
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>> "I am somewhat bemused by several references to a 'Bulb' at the bottom. We are
>> talking about a Mercury Stick Barometer, which, if my understanding of Torricelli is correct, needs to have an open reservoir to work correctly."
Yes, sorry if I've misled anyone with my description of the barometer. It is 'open' at the bottom end. The long tube curls back on itself at the bottom and opens up slightly to form a bowl/bulb. There is a black plastic screw on cap that has to be left loose. For transportation you have to fully unscrew the cap and insert a glass plug into the hole and refit the cap. I would take a picture but I do not want to disturb it anymore.
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It is actually now illegal to manufacture or supply new mercury barometers although I believe the repair of old devices is still allowed. There are now very few people who will undertake this work.
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I knew an old boy who used to renovate these, but he gave up when the restrictions on handling mercury made it very difficult.
We used to have an open trough of the stuff when I did 'O' level chemistry. Never did us any harm. I'm perfectly saneeeeeeeeeeeeeeeeeeeeeeeee.
What about mercury arc rectifiers?
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what about them? do any exist anymore?
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>> Do any exist any more?
>>
tinyurl.com/359ern
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>> We used to have an open trough of the stuff when I did 'O' level
>> chemistry.
Nobody told us about the dangers of mercury when I first started work. We used to handle it regularly when refilling u-tube manometers. The work benches used to have aluminium edgings and we found that rubbing (with bare fingers!) mercury on the edging produced a sort of white furry growth which increased rapidly. Are there any chemists out there that can tell me what the "fur" was?
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Most of us have teeth stuffed full of the stuff so wouldn't worry unduly.
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>> Most of us have teeth stuffed full of the stuff so wouldn't worry unduly.
>>
tinyurl.com/chhhfp7
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Can't help you Les, but a lad dunked his mum's wedding ring and turned it silver - she wasn't too happy and told him to turn it back to gold.
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>> Can't help you L'es, ...........
I googled and found it. tinyurl.com/csxg4xz
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No idea.
BUT if you ever have the need to be not-nice to audi owners, a small drop of mercury on exposed aluminium works wonders.
Go and search YouTube for aluminium/mercury reactions.
Or look here:
vimeo.com/32525601
That's why mercury isn't allowed on aircraft.
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If you did it yourself there would be fun and games afterwards, imagine the scene down the tip recycling centre. "Awright mate, which skip for the mercury then?"
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>> Y'all need to find a little man out in the Shires somewhere who'll
>> be overjoyed to relieve you of 50 squids for draining/refilling the critter.
Yep, that's who I'm looking for. When I go back to on Monday I'll put word round. Hopefully someone knows a little man in a shed somewhere. Used to be one in our village who actually set it up for my dad 30 years ago. He's passed away too though.
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>> He's passed away too though.
Mercury poisoning?
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I would start by entering fbhi (en.wikipedia.org/wiki/British_Horological_Institute ) into a search engine and seeing what comes up in your area.
Last edited by: VxFan on Sat 9 Jun 12 at 18:51
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>> Mercury poisoning?
lol. No, old age I think. Had an attic full of clocks. His worst nightmare was when they had to go forward / backward an hour when BST started / ended.
>> I would start by entering fbhi (en.wikipedia.org/wiki/British_Horological_Institute )
Cheers pooch. Had to edit your link as the end bracket stopped it from working.
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Removing air bubbles from a mercury barometer - devonite
