rack2000

I wonder if anyone can help.
I have a ww2 prismatic compass mk111. The body if filled with a liquid but
in mine most has "leaked" .
Would anyone know what the liquid is?. I have looked on google but cant
find any technical info. One site of a restorer said pure alchohol but the
remaining contents of mine look more like a very light oil.

Thanks Chris.

brian@brian-james.demon.co.uk

On 1-Jun-2006, "rack2000" <rack2000@rack2000.karoo.co.uk> wrote:

> I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but the
> remaining contents of mine look more like a very light oil.
>
> Thanks Chris.

Chris
under no circumstances add alcohol to the existing contents! I had an old and battered
example of this compass which had a large bubble in it. I added isopropyl alcohol and the
whole lot turned to a viscous jelly. By coincidence I bought a very good example last
Sunday at the Midlands Clock Fair and am certain that it contains compass oil since it's
movement is heavily damped. I gather from a friend that the compasses used in airplanes
used ether as a damping medium, but am sure that for compasses intended for land or marine
use a special oil is used to give a higher damping factor. At the time I did extensive
Googling but was unable to come upon a source for this oil.

Regards Brian

Greg

> At the time I did extensive
> Googling but was unable to come upon a source for this oil.

Google now produces this US company selling it:

http://www.discountweather.com/compassoil.html

Greg

=?ISO-8859-1?Q?Nick_M=FCller?=

rack2000 <rack2000@rack2000.karoo.co.uk> wrote:

> I have looked on google but cant find any technical info.

And you did google for "compass-oil"?


Nick
--
The modular DRO
Available now in USA / Canada
<http://www.yadro.de>
...|....|....|....|....|....|....|..

bugbear

rack2000 wrote:
> I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but the
> remaining contents of mine look more like a very light oil.

A google seach on groups looked helpful:

http://groups.google.com/groups/sear...ff&qt_s=Search

A quick scan of the posts indicates a wide variety of
answers, so careful reviewing of information is
probably in order.

BugBear

Jonathan Barnes

"rack2000" <rack2000@rack2000.karoo.co.uk> wrote in message
news:GSidnegHLuxjJuPZSa8jmw@karoo.co.uk...
> I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but
the
> remaining contents of mine look more like a very light oil.
>
> Thanks Chris.
>
Some instruments use glycerine.. you can get this at boots.
I think you may have something of lower viscosity than glycerine in your
compass

--
Regards Jonathan

remove AT to reply

Peter Neill

rack2000 wrote:
> I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but the
> remaining contents of mine look more like a very light oil.
>
> Thanks Chris.

It's not going to be anything very exotic given the age, time of use,
and need for an available source for any maintenance. I would suspect
it is something as simple as technical white oil (baby oil minus the
perfume). Inert, stable, cheap, and available in a range of
viscosities.

Peter

penfold

I have had some success with older compasses, refilling them with
liquid paraffin from the chemists(NOT the stuff you fire pressure
cookers with!), which is similar in viscosity to glycerine but less
prone to growing bacteria.

cheers,
David
rack2000 wrote:
> I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but the
> remaining contents of mine look more like a very light oil.
>
> Thanks Chris.

Geo

On Thu, 1 Jun 2006 11:05:59 +0100, "rack2000" <rack2000@rack2000.karoo.co.uk>
wrote:

>I wonder if anyone can help.
>I have a ww2 prismatic compass mk111. The body if filled with a liquid but
>in mine most has "leaked" .
>Would anyone know what the liquid is?. I have looked on google but cant
>find any technical info. One site of a restorer said pure alchohol but the
>remaining contents of mine look more like a very light oil.
>
Current light aircraft use this stuff:-
http://www.aircraftspruce.com/catalo...repairkit1.php

I have seen reports that some compasses are filled with paraffin and that they
used to use whisky...


Geo

Steve R.

"rack2000" <rack2000@rack2000.karoo.co.uk> wrote in message
news:GSidnegHLuxjJuPZSa8jmw@karoo.co.uk...
>I wonder if anyone can help.
> I have a ww2 prismatic compass mk111. The body if filled with a liquid but
> in mine most has "leaked" .
> Would anyone know what the liquid is?. I have looked on google but cant
> find any technical info. One site of a restorer said pure alchohol but
> the remaining contents of mine look more like a very light oil.
>
> Thanks Chris.
>
>
>

Probably glycerine! This was standard for marine compasses in the past.

Steve R.

Peter Parry

On Thu, 1 Jun 2006 11:05:59 +0100, "rack2000"
<rack2000@rack2000.karoo.co.uk> wrote:

>I wonder if anyone can help.
>I have a ww2 prismatic compass mk111. The body if filled with a liquid but
>in mine most has "leaked" .
>Would anyone know what the liquid is?. I have looked on google but cant
>find any technical info. One site of a restorer said pure alchohol but the
>remaining contents of mine look more like a very light oil.

The modern version uses a silicone fluid (Polydimethylsiloxane) and
the early ones a light mineral oil. Food grade mineral oil (better
known as Liquid Paraffin BP) might be suitable but is a little heavy.
Alternatively look at http://www.tonybridle.com/main.htm. He
services these compasses and may tell you what the correct damping
fluid is.

Be aware that the luminous paint used on the WW2 version is radium
based and somewhat radioactive.



--
Peter Parry.
http://www.wpp.ltd.uk/

Newshound

> Be aware that the luminous paint used on the WW2 version is radium
> based and somewhat radioactive.
>
I used to use mine when talking to the public (usually older groups) about
nuclear power stations. With several hundred counts per second, it's the
level which would readily be detected if you tried to take it out of a
nuclear power station. The regulations would not let you transport it in
your car without a significant amount of paperwork. As an aside, I've been
told that WW2 bomber pilots got a significant radiation dose from the
lumimous paint on their instruments. At least if they survived long enough.

Steve Richardson

> I used to use mine when talking to the public (usually older groups) about
> nuclear power stations. With several hundred counts per second, it's the
> level which would readily be detected if you tried to take it out of a
> nuclear power station. The regulations would not let you transport it in
> your car without a significant amount of paperwork. As an aside, I've been
> told that WW2 bomber pilots got a significant radiation dose from the
> lumimous paint on their instruments. At least if they survived long
enough.
>
Well thats the nanny state summed up in a nutshell !

When you didn't know if you were going to live or die, you didn't care much
for people telling you about a remote chance of something happening in the
future, you would rather have a compass you could see at night and find your
way home ! I know a sailor that had one of these in his yacht, it was so
bright he could see his way around the cabin at night.

Now we are all so cosy, the tiniest thing is getting attention and
legislation.

I have a couple of Geiger counters, and blow me I can't find the faintest
radioactive thing around except for the cosmos, which is of course blatting
us all the time. However I have spotted a large old ships compass in the
local shop, and might try it on that. Maybe I'll be able to buy it off them
cheap if its proper radium one !

Steve

Michael63

I have just come across this subject.

I am following someone's suggestion and filling my Silva (Italian)
compass
with baby oil. Cost is 5 Euros for 200 cc. in Spain and the stuff does
NOT
smell.

By the way, my compass has a rubber membrane underneath it, so I have
filled it to overflow in order to eliminate the bubble problem.

A word of advice..........put the fluid in the fridge for a while,
otherwise
you'll have the membrane collapsing when it gets cold.

(32 degrees Centigrade in Madrid !)

Cheers,
Mike


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