Silva compass question.

[upthecreek]

I got this off ebay recently (thanks wolfy). I intend to work on my navigation skills this spring. Thought this one would be pretty good. It's old. I like that.



When I first opened it, I thought something was odd. I have an old boy scout compass I've used quite a bit. They are quite similar but there is a difference I didn't expect. Wonder why the red on one points north and the white on the other points north?



Creek

[Old Philosopher]

Is that a luminescent coating on the needle?

[upthecreek]

I don't think so Ol P

Creek

[Old Philosopher]

I don't think so Ol P

Creek

The only reason I was asking:

Key points on the compass, including the north end of the needle are often marked with phosphorescent, photoluminescent, or self-luminous materials to enable the compass to be read at night or in poor light.

I guess you could shine a bright light on it tonight and find out.

Why the BSA and Silva are marked differently, I have NO clue!

[upthecreek]

I'll check them both shortly

Creek

[buzzacott]

Nah, it's definitely backwards. Your compass has reversed polarity because someone had either stored it next to iron or someone had been making the needle move around by playing a strong magnet over the compass - both are bad for accuracy.

Bad news is that it's all backwards. The good news is that since it's just a magnet inside a plastic capsule, it's reversible. You have two choices -

1. You can send the compass off to Silva USA and get them to fix the polarity issue, or

2. You can fix it yourself (keeping Silva USA's service dept. as a Plan B). To fix it, first of all you need an idea of the direction of magnetic north. Then you need to get a strong magnet such as you might find on the back of a junked car audio speaker. Point the compass body to north and then using the magnet, run it along the underside of the compass body from south to north. Do this until the red bit of the pointer points north as confirmed by another verified compass or a compass app on your phone or whatever.

Reversed polarity is a far lesser problem than something like a massive air bubble in the capsule so I'd recommend giving it a go yourself, then if it doesn't work contact Silva USA to see if they'll do an RMA and fix it for you. You'll probably have to pay shipping, but the service/repair should be covered under their Zippo-style "we'll fix it free" guarantee.

Awesome old compass and it'd be great to bring it back into service

I fix old prismatic compasses for fun (see http://thejungleisneutral.wordpress.com/2013/12/19/a-look-at-some-wwi-compasses/ for an example) so I have an inkling about how to make these things work as they should.

[Old Philosopher]

Nah, it's definitely backwards. Your compass has reversed polarity because someone had either stored it next to iron or someone had been making the needle move around by playing a strong magnet over the compass - both are bad for accuracy.

Bad news is that it's all backwards. The good news is that since it's just a magnet inside a plastic capsule, it's reversible. You have two choices -...

Possibility. I can see the arrowhead on the top compass in the photo, but the bottom compass appears to not have an arrowhead on the "north" end. Don't know if it's hidden, or not there.

[buzzacott]

Red is north.

[Old Philosopher]

Usually the North end is marked, as are the cardinal points.

Key points on the compass, including the north end of the needle are often marked with phosphorescent, photoluminescent, or self-luminous materials to enable the compass to be read at night or in poor light.

I got this off ebay recently (thanks wolfy). I intend to work on my navigation skills this spring. Thought this one would be pretty good. It's old. I like that.



When I first opened it, I thought something was odd. I have an old boy scout compass I've used quite a bit. They are quite similar but there is a difference I didn't expect. Wonder why the red on one points north and the white on the other points north?



Creek

I was just looking at this again. If you have two compasses that close together, wouldn't the North ends swing toward each other?

[wolfy]

Yeah, it has reversed polarity.....my Type 6's red end points North, but the needle IS a different shape than in the old B.S.A. Pathfinder that shows up in the picture of Creek's other old compass.  Since it is a rare old discontinued, induction-damped Type 6 that your Grandpa gave to you, have carried for years and has a lot of sentimental value,   I would call their 800# & send it back to Silva....

http://www.silvacompass.com/detail.aspx?id=76

They might even put a brand new needle in it, polish it up and replace the scratched lens if you ask them real nice!

EDIT: I noticed that, too Ol'P......but he said he noticed the reversal as soon as he unpacked it, so...

[upthecreek]

Thanks guys. (buzz has some nice compasses) I'd call it out of wack. I think I might give Silva a call and see what they say.

Creek

[Spyder1958]

Good luck creek with the rehab. I got a book for you  wolfy approved. Send over your destination.

[Old Philosopher]

Thanks guys. (buzz has some nice compasses) I'd call it out of wack. I think I might give Silva a call and see what they say.

Creek

One last stupid question, Creek. Is the needle on the Silva flat on both ends? One end pointed? No arrowhead, right?

[upthecreek]

The scout compass has an '"arrow" configuration. The silva is flat on both ends.

Creek

[Yeoman]

I always thought that reversed polarity in a compass was an wilderness legend.
Learn something new everyday.

[upthecreek]

if you ever work on a generator system that has been improperly polarized, you'd know it's not a legend.

Creek

[Professor]

I would say the needle orientation is due to anisotropy of the magnetic field domains.....(just kidding)

[Old Philosopher]

I would say the needle orientation is due to anisotropy of the magnetic field domains.....(just kidding)

The Poles shifted, and we didn't notice.

[wolfy]

I would say the needle orientation is due to anisotropy of the magnetic field domains.....(just kidding)

The Poles shifted, and we didn't notice.

East is east and West is west, and the wrong one I have chose.

[Old Philosopher]

I would say the needle orientation is due to anisotropy of the magnetic field domains.....(just kidding)

The Poles shifted, and we didn't notice.

East is east and West is west, and the wrong one I have chose.

When facing the rising sun, behind you is West. Everything else is either North, or South. Close enough for government work. 

[upthecreek]

Well, I told Silva about the cool compass that was past down from my grandfather and how much it meant to me. The very nice lady suggested I keep it and buy a new one. They will replace it without question, but won't repair it....guess I may as well send it back and get a new one 

Creek

[Old Philosopher]

Well, I told Silva about the cool compass that was past down from my grandfather and how much it meant to me. The very nice lady suggested I keep it and buy a new one. They will replace it without question, but won't repair it....guess I may as well send it back and get a new one 

Creek

  Nice back story. When you figure it probably costs them about $0.99 to build one, I'd take 'em up on their offer for a replacement. I'd guess the only way to take one apart to fix the needle would be with a big hammer.

[wolfy]

Well, I told Silva about the cool compass that was past down from my grandfather and how much it meant to me. The very nice lady suggested I keep it and buy a new one. They will replace it without question, but won't repair it....guess I may as well send it back and get a new one 

Creek

I wouldn't give up on it that easily, since it's a Type 6 induction-damped model that can never really be replaced.   The 'E clip' on the back of the Type 6 can be maneuvered into alignment with the notches in the hub that it clips into.  Once that clip comes off, it's a snap to disassemble the compass and re-magnetize the needle. Might as well clean and give it a Flitz job as long as you've got it apart!  Damn them liquid-filled sunzabiches!
                                                                       

[upthecreek]

I'm afraid I'll screw it up 

Creek

[Mr. Tettnanger]

Just get yourself a real compass (Cammenga) and stop fretting!

 

[Old Philosopher]

A GPS isn't liquid filled, nor does it have a needle. It is, however, allergic to strong magnets. They can't get demagnetized, but they can sure get deprogrammed.  I don't know which is worse, being confused, or being brain-dead.

[upthecreek]

Just get yourself a real compass (Cammenga) and stop fretting!

 

How convenient MrT! 

Creek

[Wilderbeast]

I think you should just keep your backwards compass as it is and use it as a loaner.   

[Dano]

If it's as easy to get apart as Wolfy said, it makes me wonder if one of those cheap tool magnetizer/demagnetizer things would work on it....can't make it any worse.

I was worried they would only want to replace it after my dealing with them. 

Also, remember they are owned now by Johnson Outdoors Products (at least here) and not Silva.  I wonder if you contacted Silva overseas if you'd have any better luck on a repair/rebuild.  I'd also stay away from the CL series, as much as I like them, as I've had two develop bubbles.  One is really small, but the other was replaced as most of the liquid leaked out...

Here's their foreign contact link     http://silva.se/contact-us

It's just too cool to give up on this soon!

[wolfy]

Creek, do you still have this compass gathering dust in a drawer someplace? 

[upthecreek]

of course

Creek

[wolfy]

I'm wondering if you ever attempted to reverse its present 'bassackwards' polarity?

[upthecreek]

No I never tried it wolfy.

Creek

[wolfy]

Want me to give it a whirl?

[upthecreek]

Sure, shoot me your address.

Creek

[wolfy]

Sure, shoot me your address.

Creek

Address shot.

[xj35s]

Aren't the poles going to reverse sometime soon? I'd just wait....



 




 

[upthecreek]

Well welcome to comedy central! 

Creek

[PetrifiedWood]

Just skimming the thread. I have a few suggestions. Walmart sells "headlight restorer" polish in the automotive section that works excellent on fixing scratches in clear plastic. I've used it to fix the plastic LCD screen on a walkie talkie and a GPS receiver with great results. if the scratch is really deep, you might need to sand it with successively finer grits starting around 800 or so then finish with the plastic polish.

For the needle polarity, that is easy to fix. Tilt the capsule until the needle is jammed against the top and bottom and can't rotate freely, then use a strong permanent magnet, swiping it along the direction of the needle from south to north, (I think you need to use the south pole of the magnet for this IIRC).

[wolfy]

Just skimming the thread. I have a few suggestions. Walmart sells "headlight restorer" polish in the automotive section that works excellent on fixing scratches in clear plastic. I've used it to fix the plastic LCD screen on a walkie talkie and a GPS receiver with great results. if the scratch is really deep, you might need to sand it with successively finer grits starting around 800 or so then finish with the plastic polish.

For the needle polarity, that is easy to fix. Tilt the capsule until the needle is jammed against the top and bottom and can't rotate freely, then use a strong permanent magnet, swiping it along the direction of the needle from south to north, (I think you need to use the south pole of the magnet for this IIRC).

Yeah, I'm going to try the cure with the magnet as you suggested first, PW....before going for the more drastic measures that I've employed in the past.  As for the polishing part, I've been getting real good results with Flitz metal polish.....seems to work real well on the plastic parts, also. 

I've got one REAL NICE Keuffel & Esser cruiser that has a channeled rubber retaining ring over, under and around the glass.  I need to get inside it to correct a couple of problems and I can't seem to budge it without destroying it in the process.  I can't reverse the polarity to correct its 'bassackwardness' from the outside the case.....I've tried several times without success.  I believe I could replace the glass lens, but that rubber gasket would be a real problem to replace.  I might be better off to just break the glass and try to salvage the gasket.

[upthecreek]

Wolfy... I hate to report that I cannot find the wacky compass.  It has to be here some where. I sure was looking forward to seeing if you could fix it. I'll keep my eye out for it but I did a pretty good search of my junk and could not find it in any of my likely spots.

Creek

[wolfy]

Maybe you loaned it out to someone and they got lost.

[buzzacott]

Definitely not applicable to a liquid-filled baseplate compass like an old Silva, but I successfully reversed polarity on one of those old-fashioned "decorative" Lewis and Clark wooden-cased compasses you get from places like Authentic Models (see https://www.petersofkensington.com.au/Public/Authentic-Models-Lewis-Clark-Compass.aspx)

I wanted to field test it, but unfortunately the dial was glued on crooked and the pointer, while magnetised, had the non-pointy end pointing north.

I disassembled the compass, took the pointer through one of those magnetiser/demagnetisers a few times, and it works great now, pointing north as it should.

I re-glued the paper dial in the correct orientation and hit it with some waterproofing spray just in case the compass ever gets wet. Works great now and is very accurate when compared to my British Mk III, British Verner's Pattern VIII, Cammenga M1950 and my "modern" compass, the Suunto MC-2G.