Barometers

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Nicholas123

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I have got a nice little Barometer with my new boat....the type of thing you see on many boats about 4/5" in diameter but because it was tarnished & the face was grotty I took it apart to clean it.
On disassembly I noticed that there seems to have been some sort of glue between the front face & the case & I am now wondering if it has to be sealed.There are also a couple of hole on the back.One to calibrate it but that would go up against a back bulk head or wherever you choose to mount it so maybe pressure can get in like that.The question is should they be sealed?
Also because I emeried it to get it back into a reasonable condition I guess I have now removed lacquer that would have kept it bright.Does it now need respraying or are there any other alternatives? It is of coarse brass.
 
the sealing may be to hold the glass in place. A sealed barometer would be an interesting, but useless item, so it needs holes somewhere for the bellows / pressure sensor to work.

As you have glasspapered it, there's a lot of work to bring the brass back to shiny if you want. Very very fine glasspaper (2000 grade) followed by Jeweller's rouge or a similar compound (e.g. Farecla or 3M grp polishing stuff).

Then to preserve the sparkle, something like one of the clear spray laquers from e.g. Amazon

http://www.amazon.co.uk/s/?ie=UTF8&...ex=aps&hvadid=37049534&ref=pd_sl_7x6fw8tals_b

or your local craft shop.


Personally I'd paint the case black and have done with it.
 
When I did mine I cleaned off the old varnish and then polished with brasso you can then spray with clear cellulose or a hardware shop sell small bottles of clear cellulose lacquer for coating door knockers and handles etc this you apply with a lint free cloth. As for the glass I would hold in place with clear silicon sealent.
 
sarabande said:
the sealing may be to hold the glass in place. A sealed barometer would be an interesting, but useless item, so it needs holes somewhere for the bellows / pressure sensor to work.

As you have glasspapered it, there's a lot of work to bring the brass back to shiny if you want. Very very fine glasspaper (2000 grade) followed by Jeweller's rouge or a similar compound (e.g. Farecla or 3M grp polishing stuff).

Then to preserve the sparkle, something like one of the clear spray laquers from e.g. Amazon

http://www.amazon.co.uk/s/?ie=UTF8&...ex=aps&hvadid=37049534&ref=pd_sl_7x6fw8tals_b

or your local craft shop.


Personally I'd paint the case black and have done with it.
Click to expand...

The sealing is not to hold the glass in place as it is held in a housing that itself seams to have had the glue applied & it has come up beautifully with just the coarse...ish emery that I have used.It would be sacrilege to paint it black :eek:.I shall take a look at the link you have provided.Thanks.
 
Geoff Enigma said:
When I did mine I cleaned off the old varnish and then polished with brasso you can then spray with clear cellulose or a hardware shop sell small bottles of clear cellulose lacquer for coating door knockers and handles etc this you apply with a lint free cloth. As for the glass I would hold in place with clear silicon sealent.
Click to expand...

I was thinking of a bit of Vaseline between the two joints,maybe to prevent damp sea air getting in & tarnishing the face again with the sort of mold that you see so common in a marine environment.I guess it is that that made such a mess of the face,thanks.
 
I would try polishing the face with WD40 as this leaves a thin film of protection over the surface it’s also good to bring up black and blushed aluminium fascias I used to use this trick to refurbish audio equipment.
 
My sister trained as a jeweller, and for laquering they use spray-laquer thinned 50% with laquer-thinners and aoolied with a very soft brush. Of course the product has to be clean- use meths or acetone first, but it works like a bomb!
 
Nicholas123 said:
I have got a nice little Barometer with my new boat....the type of thing you see on many boats about 4/5" in diameter but because it was tarnished & the face was grotty I took it apart to clean it.
On disassembly I noticed that there seems to have been some sort of glue between the front face & the case & I am now wondering if it has to be sealed.There are also a couple of hole on the back.One to calibrate it but that would go up against a back bulk head or wherever you choose to mount it so maybe pressure can get in like that.The question is should they be sealed?
Also because I emeried it to get it back into a reasonable condition I guess I have now removed lacquer that would have kept it bright.Does it now need respraying or are there any other alternatives? It is of coarse brass.
Click to expand...

The fixative between the glass bezel and the case is intended to anchor it in place. Additionally the glass itself ought to be anchored to the bezel otherwise turning the setting hand may cause the glass to rotate with it.

The adjusting screw at the back is used to calibrate the barometer according to altitude. I take it you will use it on board ?

If that is the case obtain an accurate reading from the nearest met staion for sea level and alter accordingly.

Generally if the difference before adfusting is more than 5 millibars you ought to remove the hand and replace to a closer setting and then use the setting screw for a closer reading.

You ought to pay attention to replace the dial itself as you found it and some barometers have tiny screws to hold the dial in place. Others have other arrangements such as pegs or slots with male-female engagement.

The brass can be varnished using clear nail varnish which is cheap and effective with the added bonus you can remove it using acetone nail varnish remover at any time. The finish is damp proof and very reiable.

To test the action of the needle in an Aneroid, place inside a clear plastic bag with air in it and squeeze the bag, you will see the needle reacting immediately.

To check for loss in pressure you have to wait for a decline or you can use a dinghy reverse pump to check.

The setting hole at the back is enough for air to get in and out in any event/
 
nigelmercier said:
As opposed to fine brass? :)

I was delighted to discover that my brass barometer was broken, it wouldn't go above 1016mB. This meant that I could get rid of the grotty thing, and the matching clock, and get a nice electronic one with a barograph, radio controlled clock, sun and moon times ...
Click to expand...

:cool:

Not as pretty but loads more useful.
 
I love the old traditional kit. I've just bought a proper lead and line on the Bay for £3.50. Just need a bit of tallow and I can properly say I'm just swinging the lead :D Just need now to find an affordable Walker log....... and a sextant.
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Nicholas123 said:
Neither had an engine so what would they run them on? Look after the pennies & the pounds take care of themselves ;)
Click to expand...

Done that no engine thing. Way too stressful, hopefully never again. :(

Battery in the cheap electric barometer stuck to the bulkhead lasts for years.

Right now says it´s going to rain. :(

Who need´s ´em ;)
 
nigelmercier said:
As opposed to fine brass? :)

I was delighted to discover that my brass barometer was broken, it wouldn't go above 1016mB. This meant that I could get rid of the grotty thing, and the matching clock, and get a nice electronic one with a barograph, radio controlled clock, sun and moon times ...
Click to expand...
I appear to be ploughing a lonely furrow when I admit to having a wind up barograph and conventional barometer on board our boat. I cannot bring myself to think of real progress being an electronic weather station...

The one concession to modernity in this area is that we have a battery powered quartz crystal controlled clock... but it matches the barometer!
 
Real progress........I can't resist this one.To quote from Peter Tangvald an incredible character (as I'm sure anyone who has read his books will appreciate).

"It is a wonderful experience to cross a large ocean successfully under sail alone.It is hard to describe the sensation of happiness,of freedom and of general satisfaction given by such a voyage.It is true that the best part of such a voyage is to see the landfall,but this is not because we will again be able to get ashore,but rather because it is the culmination of our effort and proves that the voyage was successful and the navigation accurate.Every day spent aboard during the voyage was well worth living,even including the one when the weather was less pleasant.
I would never lose the wonderful atmosphere and romance of sail which can only be experienced in a true sailing boat.And by true sailing boat I mean one which is not spoilt by any of the modern mechanics and gadgets.I mean one which simply uses the wind as propulsion and uses it in the same way as our forefathers have done for several thousands of years and has proven satisfactory with a minimum of headaches,a minimum of expenses and a minimum of failures.Why should modern people always feel so sure of being smarter than our forefathers?Just because we have stumbled into the combustion engine and from there into the atomic age?But that does not mean that our intelligence has grown,nor indeed does it prove that we are any happier."

Not everyone will agree with him but I can't see why I need info on the sun & the moon when I'm out there experiencing it at first hand nor do I understand what use a barograph is or even particularly a barometer.......

& on the subject of pretty useless bits of kit.Why do so many insist on having a windometer or whatever you call it at the top of the mast? :confused:
 
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