Blades and Bushlore

Bushlore Topics => Bushlore and Outdoor Skills => Topic started by: upthecreek on March 05, 2014, 04:06:14 PM

Title: Silva compass question.
Post by: upthecreek on March 05, 2014, 04:06:14 PM
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.

(http://i817.photobucket.com/albums/zz100/tottaway/IMG_0539.jpg) (http://s817.photobucket.com/user/tottaway/media/IMG_0539.jpg.html)

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?

(http://i817.photobucket.com/albums/zz100/tottaway/IMG_0544.jpg) (http://s817.photobucket.com/user/tottaway/media/IMG_0544.jpg.html)

Creek
Title: Re: Silva compass question.
Post by: Old Philosopher on March 05, 2014, 04:16:15 PM
Is that a luminescent coating on the needle?
Title: Re: Silva compass question.
Post by: upthecreek on March 05, 2014, 04:25:39 PM
I don't think so Ol P

Creek
Title: Re: Silva compass question.
Post by: Old Philosopher on March 05, 2014, 04:32:36 PM
I don't think so Ol P

Creek
The only reason I was asking:

Quote
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!
Title: Re: Silva compass question.
Post by: upthecreek on March 05, 2014, 04:35:29 PM
I'll check them both shortly

Creek
Title: Re: Silva compass question.
Post by: buzzacott on March 05, 2014, 04:36:19 PM
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.
Title: Re: Silva compass question.
Post by: Old Philosopher on March 05, 2014, 04:44:26 PM
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.
Title: Re: Silva compass question.
Post by: buzzacott on March 05, 2014, 04:54:37 PM
Red is north.
Title: Re: Silva compass question.
Post by: Old Philosopher on March 05, 2014, 05:33:00 PM
Usually the North end is marked, as are the cardinal points.

Quote
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.

(http://i817.photobucket.com/albums/zz100/tottaway/IMG_0539.jpg) (http://s817.photobucket.com/user/tottaway/media/IMG_0539.jpg.html)

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?

(http://i817.photobucket.com/albums/zz100/tottaway/IMG_0544.jpg) (http://s817.photobucket.com/user/tottaway/media/IMG_0544.jpg.html)

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?
Title: Re: Silva compass question.
Post by: wolfy on March 05, 2014, 05:35:58 PM
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, ;D O:-)  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! O:-) :shrug:

EDIT: I noticed that, too Ol'P......but he said he noticed the reversal as soon as he unpacked it, so... :shrug:
Title: Re: Silva compass question.
Post by: upthecreek on March 05, 2014, 06:17:55 PM
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
Title: Re: Silva compass question.
Post by: Spyder1958 on March 05, 2014, 07:19:00 PM
Good luck creek with the rehab. I got a book for you  :) wolfy approved. Send over your destination.
Title: Re: Silva compass question.
Post by: Old Philosopher on March 05, 2014, 09:24:17 PM
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?
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2014, 04:10:58 AM
The scout compass has an '"arrow" configuration. The silva is flat on both ends.

Creek
Title: Re: Silva compass question.
Post by: Yeoman on March 06, 2014, 06:43:44 AM
I always thought that reversed polarity in a compass was an wilderness legend.
Learn something new everyday.
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2014, 07:51:05 AM
if you ever work on a generator system that has been improperly polarized, you'd know it's not a legend.

Creek
Title: Re: Silva compass question.
Post by: Professor on March 06, 2014, 12:56:43 PM
I would say the needle orientation is due to anisotropy of the magnetic field domains.....(just kidding)

Title: Re: Silva compass question.
Post by: Old Philosopher on March 06, 2014, 01:25:23 PM
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.
Title: Re: Silva compass question.
Post by: wolfy on March 06, 2014, 03:35:48 PM
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. :P
Title: Re: Silva compass question.
Post by: Old Philosopher on March 06, 2014, 03:50:39 PM
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. :P

When facing the rising sun, behind you is West. Everything else is either North, or South. Close enough for government work.  :P
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2014, 04:24:46 PM
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  :rofl:

Creek
Title: Re: Silva compass question.
Post by: Old Philosopher on March 06, 2014, 04:49:59 PM
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  :rofl:

Creek

 :thumbsup: 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.
Title: Re: Silva compass question.
Post by: wolfy on March 06, 2014, 05:09:23 PM
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  :rofl:

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!
                                                                        :soap:
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2014, 07:21:17 PM
I'm afraid I'll screw it up  :-[

Creek
Title: Re: Silva compass question.
Post by: Mr. Tettnanger on March 06, 2014, 08:02:57 PM
Just get yourself a real compass (Cammenga) and stop fretting!

 :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :camp: :cheers:
Title: Re: Silva compass question.
Post by: Old Philosopher on March 06, 2014, 08:21:21 PM
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.
Title: Re: Silva compass question.
Post by: upthecreek on March 07, 2014, 04:38:18 AM
Just get yourself a real compass (Cammenga) and stop fretting!

 :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :camp: :cheers:

How convenient MrT!  :rofl:

Creek
Title: Re: Silva compass question.
Post by: Wilderbeast on March 07, 2014, 05:25:25 AM
I think you should just keep your backwards compass as it is and use it as a loaner.   >:D

Title: Re: Silva compass question.
Post by: Dano on March 07, 2014, 05:40:33 AM
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!
Title: Re: Silva compass question.
Post by: wolfy on March 05, 2017, 06:41:21 PM
Creek, do you still have this compass gathering dust in a drawer someplace?  ???
Title: Re: Silva compass question.
Post by: upthecreek on March 05, 2017, 07:00:10 PM
of course

Creek
Title: Re: Silva compass question.
Post by: wolfy on March 05, 2017, 08:59:42 PM
I'm wondering if you ever attempted to reverse its present 'bassackwards' polarity?:shrug:
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2017, 04:16:28 AM
No I never tried it wolfy.

Creek
Title: Re: Silva compass question.
Post by: wolfy on March 06, 2017, 07:55:16 AM
Want me to give it a whirl? ???
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2017, 09:11:36 AM
Sure, shoot me your address.

Creek
Title: Re: Silva compass question.
Post by: wolfy on March 06, 2017, 09:28:39 AM
Sure, shoot me your address.

Creek

Address shot. 8)
Title: Re: Silva compass question.
Post by: xj35s on March 06, 2017, 12:14:00 PM
Aren't the poles going to reverse sometime soon? I'd just wait....



 :rofl:




 :doh:
Title: Re: Silva compass question.
Post by: upthecreek on March 06, 2017, 03:47:53 PM
Well welcome to comedy central!  :cheers:

Creek
Title: Re: Silva compass question.
Post by: PetrifiedWood on March 06, 2017, 06:43:54 PM
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).
Title: Re: Silva compass question.
Post by: wolfy on March 06, 2017, 08:03:20 PM
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. :shrug:
Title: Re: Silva compass question.
Post by: upthecreek on March 11, 2017, 09:19:17 AM
Wolfy... I hate to report that I cannot find the wacky compass.  :shrug: 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
Title: Re: Silva compass question.
Post by: wolfy on March 11, 2017, 10:06:18 AM
Maybe you loaned it out to someone and they got lost. :shrug:
Title: Re: Silva compass question.
Post by: buzzacott on September 22, 2017, 11:49:24 PM
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.