My copper wire doesn't conduct (???) - SailNet Community
 2Likes
Reply
 
LinkBack Thread Tools
post #1 of 21 Old 04-06-2017 Thread Starter
Senior Member
 
TakeFive's Avatar
 
Join Date: Oct 2009
Location: Swarthmore, PA
Posts: 3,893
Thanks: 12
Thanked 102 Times in 91 Posts
Rep Power: 8
 
My copper wire doesn't conduct (???)

I've been trying to wire a new RAM mic in my cockpit (as described on another thread). I removed the old RAM mic (which was working fine), and planned to re-use its wire so I don't have to re-run the new wire through the binnacle guard. So I clipped off the connectors at both ends of the old wire, and tried to splice the new connectors onto the old wire. I've had difficulties getting a good splice, which I had attributed to the splicing connectors that I was using being incompatible with the very tiny gauge wire. I just tried some new connectors, and they did not work either. So I went and did some continuity checks on the wire itself, and was shocked to see that the copper wire does not appear to conduct electricity.

In the pics below, you can see that I took the copper shielding wire and wrapped it around both probe tips, and show no continuity. For you cynics out there, the second picture shows clearly that when the probe tips touch each other, there is continuity, so it does not appear to be a problem with my cheapo multimeter. FYI, the copper strands do not appear to have any sort of clear lacquer or other insulating material on them. I tried checking continuity of some of the other conductors, and had the same problems.

As I mentioned before, the old RAM mic that was connected with these wires worked fine. (I'm replacing it because I upgraded my VHF to a new model, which needs a new model of RAM mic.)

Does anyone have any suggestions?
Attached Thumbnails
Copper wire.jpg   Probe tips.jpg  

Rick S., Swarthmore, PA
USCG Certified Captain, 50 Ton Master and OUPV
ASA Certified 101/103/104/105/106



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2001 Catalina 34MkII Tall Rig Breakin' Away, Universal Diesel M35B, Mantus 35 lb. anchor, sailing out of Rock Hall Landing Marina

Last edited by TakeFive; 04-06-2017 at 11:12 PM.
TakeFive is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 21 Old 04-06-2017
Dirt Free
 
boatpoker's Avatar
 
Join Date: Jul 2008
Location: Toronto
Posts: 1,681
Thanks: 20
Thanked 67 Times in 64 Posts
Rep Power: 9
 
Re: My copper wire doesn't conduct (???)

You appear to be testing two wires coming out of one end of the cable. What colours are contacting your probe in photo #1 ? You can't test continuity at only one end of the cable. You need to test a wire for continuity from one end to the other. i.e. one end of the black to the other end of the black.

What you can test at one end of the cable is voltage between red and black which will tell you if there is power there.

The hysterical laughter you hear as you drive a way in your"new" boat ..... is the seller.
boatpoker is online now  
Quote Quick Reply Share with Facebook
post #3 of 21 Old 04-06-2017 Thread Starter
Senior Member
 
TakeFive's Avatar
 
Join Date: Oct 2009
Location: Swarthmore, PA
Posts: 3,893
Thanks: 12
Thanked 102 Times in 91 Posts
Rep Power: 8
 
Re: My copper wire doesn't conduct (???)

I am not testing two different wires in this picture. The colored insulated wires you see are just dangling off the side, and not part of the test.

I had initially tested the uninsulated copper shielding wire at both ends and got no continuity. For purposes of this picture (since I only have two hands, and wanted to keep everything compact to snap a close-up) I took a 1.5" length of the copper shielding strands that were coming out of one end of the wire bundle, and wrapped that short length around both probes. So in this case I see no continuity through a 1" length of copper wire!

The wire is disconnected - it's not carrying any voltage. I'm measuring resistance to determine continuity.

Rick S., Swarthmore, PA
USCG Certified Captain, 50 Ton Master and OUPV
ASA Certified 101/103/104/105/106



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2001 Catalina 34MkII Tall Rig Breakin' Away, Universal Diesel M35B, Mantus 35 lb. anchor, sailing out of Rock Hall Landing Marina
TakeFive is offline  
Quote Quick Reply Share with Facebook
 
post #4 of 21 Old 04-07-2017
Senior Member
 
overbored's Avatar
 
Join Date: Oct 2010
Location: Dana Point, Ca
Posts: 1,968
Thanks: 1
Thanked 131 Times in 130 Posts
Rep Power: 7
 
Re: My copper wire doesn't conduct (???)

must be a coating on the wire or there is just enough oxide on the wire to not pass any current. scrape the wire to get clean copper and test it. I have seen this happen on copper ground connectors on aircraft. we had a 5/16" stud for ground and a brand new ground strap with no continuity through the connection. surface oxide was enough to stop any electrons.
seabeau likes this.

"FULL TILT II" 2011 BENETEAU FIRST 30
"GOLD RUSH" PRINDLE 16
overbored is online now  
Quote Quick Reply Share with Facebook
post #5 of 21 Old 04-07-2017
Mermaid Hunter
 
SVAuspicious's Avatar
 
Join Date: Oct 2006
Location: on the boat - Chesapeake
Posts: 5,687
Thanks: 0
Thanked 274 Times in 246 Posts
Rep Power: 11
 
Re: My copper wire doesn't conduct (???)

First: https://www.fastenal.com/products/details/0710538

The lack of continuity is odd. My first guess is varnish. Scrapping or sanding can work but is frustrating. Try burning it off with a lighter or small torch.

sail fast and eat well, dave S/V Auspicious

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

beware "cut and paste" sailors


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
SVAuspicious is offline  
Quote Quick Reply Share with Facebook
post #6 of 21 Old 04-07-2017
4KSB driver.
 
SHNOOL's Avatar
 
Join Date: Jun 2007
Location: East Stroudsburg, PA
Posts: 2,390
Thanks: 11
Thanked 143 Times in 136 Posts
Rep Power: 11
 
Dock
Re: My copper wire doesn't conduct (???)

I vote burn... must be oil or wax or something... but his question is more serious, because if he cannot get good conductivity to the ground plane, on one end, anyone realize how cruddy it must be at the other?

1983 WD Schock Wavelength 24. Production boat limit tester, blue-water bucket owner, with wine taste on a beer budget.
SHNOOL is online now  
Quote Quick Reply Share with Facebook
post #7 of 21 Old 04-07-2017 Thread Starter
Senior Member
 
TakeFive's Avatar
 
Join Date: Oct 2009
Location: Swarthmore, PA
Posts: 3,893
Thanks: 12
Thanked 102 Times in 91 Posts
Rep Power: 8
 
Re: My copper wire doesn't conduct (???)

Quote:
Originally Posted by SHNOOL View Post
I vote burn... must be oil or wax or something... but his question is more serious, because if he cannot get good conductivity to the ground plane, on one end, anyone realize how cruddy it must be at the other?
Hi John, I am not working with the actual wire on the boat, I am doing my splice testing in the comfort of my home with an excess piece of wire that I clipped from inside my cabin. The wire's condition is pristine - no corrosion at all, just perfectly shiny copper wire.

I'll try Dave's suggestion of burning off any varnish layer and redo my test on the bare-looking shielding conductors. But the wire strands inside the colored insulation also failed continuity. Would those be varnished also?

Rick S., Swarthmore, PA
USCG Certified Captain, 50 Ton Master and OUPV
ASA Certified 101/103/104/105/106



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2001 Catalina 34MkII Tall Rig Breakin' Away, Universal Diesel M35B, Mantus 35 lb. anchor, sailing out of Rock Hall Landing Marina
TakeFive is offline  
Quote Quick Reply Share with Facebook
post #8 of 21 Old 04-07-2017
Mermaid Hunter
 
SVAuspicious's Avatar
 
Join Date: Oct 2006
Location: on the boat - Chesapeake
Posts: 5,687
Thanks: 0
Thanked 274 Times in 246 Posts
Rep Power: 11
 
Re: My copper wire doesn't conduct (???)

Quote:
Originally Posted by TakeFive View Post
I'll try Dave's suggestion of burning off any varnish layer and redo my test on the bare-looking shielding conductors. But the wire strands inside the colored insulation also failed continuity. Would those be varnished also?
Hmm. Seems unlikely. Please report back.

sail fast and eat well, dave S/V Auspicious

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

beware "cut and paste" sailors


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
SVAuspicious is offline  
Quote Quick Reply Share with Facebook
post #9 of 21 Old 04-07-2017
4KSB driver.
 
SHNOOL's Avatar
 
Join Date: Jun 2007
Location: East Stroudsburg, PA
Posts: 2,390
Thanks: 11
Thanked 143 Times in 136 Posts
Rep Power: 11
 
Dock
Re: My copper wire doesn't conduct (???)

Yeah, seems very unlikely... and its enough of a problem that I'd call suspect on all of the wire. In your situation I'd create a loop of the existing wire, burn/tin the ends with solder to verify good conductivity, and retest via the ends.

Sometimes the coating on the probes are funny with dissimilar metals as well. Its rare, but I've been bitten by it before. Actually Ive seen voltage drops at a distance measured from the battery for the same reason... test and get 4-8V, then test again and get 12V, then 4-8, and its merely the probe not making complete enough contact... but for sure this is pretty odd indeed.

1983 WD Schock Wavelength 24. Production boat limit tester, blue-water bucket owner, with wine taste on a beer budget.
SHNOOL is online now  
Quote Quick Reply Share with Facebook
post #10 of 21 Old 04-07-2017
Senior Member
 
Join Date: Feb 2011
Location: San Francisco Bay area
Posts: 3,073
Thanks: 9
Thanked 83 Times in 82 Posts
Rep Power: 7
 
Re: My copper wire doesn't conduct (???)

My vote is for an intermittent connection in your meter leads. It's all just coincidence. Sometimes they conduct, sometimes they don't. Broken wire?

Bristol 31.1, San Francisco Bay
MarkSF is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
heat exchanger, copper or copper/nickel? douglasb Diesel 5 07-19-2014 10:33 AM
Oman Sail to conduct ‘Try Sailing' programme NewsReader News Feeds 0 09-14-2012 07:30 PM
Wisconsin Rep. Brett Hulsey convicted of disorderly conduct - Green Bay Press Gazette NewsReader News Feeds 0 08-31-2012 04:30 PM
Sar Techs Conduct Daring Sailboat Rescue - Canada.com NewsReader News Feeds 0 07-21-2012 04:50 AM
Copper wire for marine use? TakeFive Gear & Maintenance 9 05-16-2010 10:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome