Care for your compass???

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yomperalex

Nomad
Jan 22, 2011
260
1
Reading
Folks

I have a couple of compasses that are no longer any good - erratic pointing and taking ages to settle.

They were both left in the car for a while, and I can't help wondering if being near to a large lump of iron (the engine block) has degraded the magnetism.

can this kind of thing happen?

Should I try and keep my compass out of the car as much as possible, and as far away from the engine block as possible when it must go in the car.

Or am I on the wrong track completely, and I just need to buy a better compass?

TIA

Alex
 
Nov 29, 2004
7,808
22
Scotland
"... I can't help wondering if being near to a large lump of iron (the engine block) has degraded the magnetism. can this kind of thing happen?.."

If it is something like a Silva compass I wouldn't imagine so, however I am happy to be corrected, my Silva 15, 54 and a few smaller ones usually sit in bags and packs next to metal items and I have not noticed a problem, so far anyway. :)
 

ol smokey

Full Member
Oct 16, 2006
433
2
Scotland
You may find that your compass has gone wonky, due to having been stored in the glove compartment of your car,and itis not the proximity to the engine block that is the problem, but being too close to the motor which drives the windscreen wipers. This has even been known to reverse the polarity of the Compass so that it points to South instead of North.
As to if it can be cured or not, if it is made by Silva, and is one of their more expensive models, they may be able to do something for you, otherwise I think that you just put it down to experience. It is not a fault in the compass itself as anything with electrical motors or circuits, like a Radio, could have the same effect if too close. Hope that this is of help.
 
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Joonsy

Native
Jul 24, 2008
1,483
3
UK
devices such as mobile phones and gps or anything electrical like radios etc is said to effect the magnetism (do you have a gps in car, radio, keep compass by them?) though i have not personally suffered this myself. Is your compass a good liquid-filled one, budget ones are often non-liquid-filled hence don't settle well, i use a silva type 4.
 

Goatboy

Full Member
Jan 31, 2005
14,956
17
Scotland
Yup as Ol' Smokey says the motor from your wipers can be deadly to a compass, as can the speakers from the stereo. Needn't be terminal though, you can re-magnetise it your self (see video) or a good outdoor retailer should be able to do it for you.
[video=youtube;GuIkvUTxYdU]http://www.youtube.com/watch?v=GuIkvUTxYdU[/video]

If it's a case that the oil has leaked out of the case then the needle will always be slow to settle, and will also oxidise over time causing further problems. Some compasses have replaceable housings though the non ferrous retaining clips can be fun to manipulate! Sometimes with a less expensive compass it's worth while biting the bullet and just replacing the whole thing.


Another thing that can cause problems with compasses that can escape your notice is those magnetic bracelets that some wear for arthritis. Will throw it off big style. Couldn't understand why one class of slightly older walkers I was teaching could navigate perfectly on paper in the class but wandered all about on the hill. Some were wearing those bracelets and it took a while for me to figure that that was the problem.


I always keep my compass well away from stereos, personal radio and mobile phone and if transporting in a vehicle keep in in the boot away from any rear speakers. Also periodically check it against known north. If the polarity has been reversed you can navigate just as almost as easily though there is a little mental arithmetic involved.

On the buying a better compass I'm all for spending a little on a decent compass. (You don't have to go mad though). I mainly use a Sliva Expedition 4 which will set you back around £25-30. Has a decent sized base plate with some very useful roamers on it.

For more exacting work I'll turn to something like a Silva 15DCL 360 or a Suunto KB series though the later is maybe a bit more specialised for surveying/forestry.

It depends on what you're doing and as I say you don't have to go mad. I also tend to carry at least one other cheaper compass as a back up if I'm going to be navigating across larger distances or difficult terrain especially if bad weather is expected and good compass work is to be expected/needed.

A lot of folks have gone to digital compasses, and though they have their place they have a few drawbacks; the batteries can die, they tend to be jittery and not as simple to read in conjunction with a map. So although I have one on my Suunto watch it's rarely used bar to find north quickly when I go to a new place. The other features that come with it like altimeter and barometer are much more useful to me.
 

ged

Bushcrafter (boy, I've got a lot to say!)
Jul 16, 2009
4,976
13
In the woods if possible.
Always be aware of the risk that there might be large lumps of metal nearby, especially steel or iron, when you're using a magnetic compass. Last year when I was surveying badger setts in Gloucestershire I decided that there was something wrong with one of my bearings, it was off by about twenty degrees. When I went back there and looked around I found a large steel beam hidden in the hedge bottom about three feet from where I took the bearing. It looked like it had been used as a gate post at some time and then discarded.

The same goes for magnetic materials on your person. Headphones for example can contain strong magnets, and cameras and mobiles too. The material doesn't even have to have been intended for use as a magnet to cause problems, any material that can become a magnet will do so anytime it is placed in a magnetic field - like the one that your compass is showing you.

If you have doubts about a compass, check around you -- there might be nothing wrong with the compass!
 

dwardo

Bushcrafter through and through
Aug 30, 2006
6,451
475
46
Nr Chester
I found my suunto watch compass was out every time I checked one week. Tracked it down to using my pillar drill, big ole electirc motor will do it every time.
Being digital easy to reset.
 

tombear

On a new journey
Jul 9, 2004
4,494
556
54
Rossendale, Lancashire
Although I can't put my hands on it I used to have a old army manual that gave the distances you needed to be from various objects so that your compass wouldn't be affected by it. So many feet from a rifle, jeep, 3 tonner, metal gate etc. Does any one have something similar to put up?

i always smile when you see the hero in a film get off his tank and squint at his compass while standing next to 30 tons of iron and several electric motors, radio etc...

atb

Tom
 

yomperalex

Nomad
Jan 22, 2011
260
1
Reading
I have definitely been leaving it in the glove compartment, so I think that one is solved - boot - and take it out for longer term storage, away from gadgets etc.

Thanks everybody.

Alex
 

Seagull

Settler
Jul 16, 2004
902
108
Gåskrikki North Lincs
Evening Alex. Compass care was a big deal for mariners of yore.
Even today, most all electrical equipment you find on the Bridge, is likely to have a small panel on the reverse, showing its compass safe distance. The other effects were monitored by regular compass error obs's and annual deviation swings were verified by those same obs's.
 

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