DIY Cable Questions and Comments Thread
Mar 4, 2015 at 12:10 PM Post #3,601 of 10,535
 
Uhmmm... not true.  Maybe if you are not tinning before you solder, you could get a good mechanical connection between the two conductive surfaces.  Until you solder the joint that is.  When soldering the joint it would take more pressure than you can provide with the tip of your soldering iron to keep that mechanical connection.  You actually want that solder to flow and fill all of the gaps between the two conductive surfaces, many of which a too small for you to see without magnification.  If it doesn't flow properly to fill those gaps it is what's known as a "cold solder" joint which does not conduct electricity very well.  If you want that perfect mechanical connection, that would be welding, which produces way too much residual heat for our connectors to survive.

You mean I can't weld my solder to my adapters!? Darn... :p I think I'm going to get some Cardas Quad Solder as it is said to be very high quality stuff
 
Mar 4, 2015 at 12:39 PM Post #3,602 of 10,535
 
Uhmmm... not true.  Maybe if you are not tinning before you solder, you could get a good mechanical connection between the two conductive surfaces.  Until you solder the joint that is.  When soldering the joint it would take more pressure than you can provide with the tip of your soldering iron to keep that mechanical connection.  You actually want that solder to flow and fill all of the gaps between the two conductive surfaces, many of which a too small for you to see without magnification.  If it doesn't flow properly to fill those gaps it is what's known as a "cold solder" joint which does not conduct electricity very well.  If you want that perfect mechanical connection, that would be welding, which produces way too much residual heat for our connectors to survive.

 
I agree with you, but isn't welding pretty much the same thing as soldering? The 2 welded surfaces still got those 'gaps', it's just the surrounding that is joined together with the welding. I'd imagine to get that really perfect mechanical connection would be by 'forging'. Heat the 2 surfaces until glowing red and almost melt, then hammer them together before they cool off. Now that's a perfect connection :)
 
Mar 4, 2015 at 12:50 PM Post #3,603 of 10,535
  Hmmmm, I would say yes and no to that.
  No, a solder also acts, or add/help/supplement in conductivity. That's why it's made of conductive materials as well.

 
  Uhmmm... not true.  Maybe if you are not tinning before you solder, you could get a good mechanical connection between the two conductive surfaces.  Until you solder the joint that is.  When soldering the joint it would take more pressure than you can provide with the tip of your soldering iron to keep that mechanical connection

 
 
What I meant was that people should not be making connections based purely on solder (making bridges essentially). The conductivity of solder is quite poor.
 
Mar 4, 2015 at 1:02 PM Post #3,604 of 10,535
   
I agree with you, but isn't welding pretty much the same thing as soldering? The 2 welded surfaces still got those 'gaps', it's just the surrounding that is joined together with the welding. I'd imagine to get that really perfect mechanical connection would be by 'forging'. Heat the 2 surfaces until glowing red and almost melt, then hammer them together before they cool off. Now that's a perfect connection :)

A good weld with proper "penetration" joins the two metals together as one.  Penetration in a weld is how deep the metal was heated beyond it's critical temperature and was able to flow together mixing the metals of the pieces being joined.  Heating the metal to glowing red [right at the critical temperature, but not beyond] would not provide as good as a connection as the two metals would not be able to flow together and make a strong joint.
 
Mar 4, 2015 at 1:23 PM Post #3,605 of 10,535
Just bought some Cardas Quad from here http://www.ebay.com/itm/25g-Solder-Cardas-Quad-Silver-Eutectic-Solder-Authorized-Cardas-Dealer-/400607789415?pt=LH_DefaultDomain_0&hash=item5d4615c167
 
Will let you guys know how well it works... Apparently this stuff is really high quality
 
Mar 4, 2015 at 2:11 PM Post #3,607 of 10,535
   
I agree with you, but isn't welding pretty much the same thing as soldering? The 2 welded surfaces still got those 'gaps', it's just the surrounding that is joined together with the welding. I'd imagine to get that really perfect mechanical connection would be by 'forging'. Heat the 2 surfaces until glowing red and almost melt, then hammer them together before they cool off. Now that's a perfect connection :)

 
  A good weld with proper "penetration" joins the two metals together as one.  Penetration in a weld is how deep the metal was heated beyond it's critical temperature and was able to flow together mixing the metals of the pieces being joined.  Heating the metal to glowing red [right at the critical temperature, but not beyond] would not provide as good as a connection as the two metals would not be able to flow together and make a strong joint.

 
 
Forging is also a generic term that means shaping metal by applied force (hammering, pressing, etc). Heat isn't even necessary.
 
Welding joins two materials together (flows them back together; they are metallurgically bonded). There may or may not be a filler material involved. Heat is usually involved but in some cases not.
 
Soldering and brazing connects two material through a filler material.
 
 
For cables, in an ideal world we would be able to create metallurgical bonds, but this is impractical and very expensive on small scales.
 
Mar 4, 2015 at 2:12 PM Post #3,608 of 10,535
  A good weld with proper "penetration" joins the two metals together as one.  Penetration in a weld is how deep the metal was heated beyond it's critical temperature and was able to flow together mixing the metals of the pieces being joined.  Heating the metal to glowing red [right at the critical temperature, but not beyond] would not provide as good as a connection as the two metals would not be able to flow together and make a strong joint.

 
Ah ok, noted. New thing learned...
 
Mar 4, 2015 at 2:21 PM Post #3,609 of 10,535
   
Do you have any backing for that? Because as far as i was taught, a good solder between two points gives anything but a poor conductivity.

 
Lead and tin have terrible conductivity. Here's a chart, copper is "1". Everything else is a multiple of the resistivity of copper (I think silver is... 0.95 or something like that).
http://www.microwaves101.com/encyclopedias/soldering-basics#chart
 
Mar 4, 2015 at 2:25 PM Post #3,610 of 10,535

A lead tin alloy solder actually has almost the same resistance and conductivity as pure copper wire.  You can look up the individual metals base measurements here: http://chemistry.about.com/od/moleculescompounds/a/Table-Of-Electrical-Resistivity-And-Conductivity.htm
 
As you can see, Copper has a resistance of 1.68×10−8 and conductivity of 5.96×107.  Lead has a resistance of 2.2×10−7 [higher than copper] and conductivity of 4.55×106 [lower than copper].  Tin has a resistance of 1.09×10−7 [lower than copper] and conductivity of 9.17×106 [higher than copper].  As an alloy these qualities are averaged [for the most part] as per the alloy composition.  A 65/35 solder has almost the same resistance and conductivity as copper but a higher melting point than 60/40 which is probably why 60/40 is more popular.  Still, the difference between the two is almost immeasurable and definitely can't be heard through the few connections we make in our cables.
 
Mar 4, 2015 at 2:52 PM Post #3,612 of 10,535
   
Ah, you wanted 2 wires in one sleeve. Thats not much room to work with. But that is also why I recommended you check out the other cables redco has in store.
Have you thought about maybe sleeve each wire and braid them? Should make your options a bit better.

 
Hmm...
 
This sleeving (Nylon Soft 2mm) truly have small room, but... I'am going to make IEM, so when I'am using thick cable they looks - not as good as I'd like to...
 
I can try braid two cables in this sleevings but, the question is how... Cabel for IEM should be elastic, two wires probably will untie. I mean three wires always hold themselves, two wires need glue, or non elastic cables, or something else.
 
Anyway, I am going to check Redco.
 
Mar 4, 2015 at 3:23 PM Post #3,613 of 10,535
 
A lead tin alloy solder actually has almost the same resistance and conductivity as pure copper wire.  You can look up the individual metals base measurements here: http://chemistry.about.com/od/moleculescompounds/a/Table-Of-Electrical-Resistivity-And-Conductivity.htm
 
As you can see, Copper has a resistance of 1.68×10−8 and conductivity of 5.96×107.  Lead has a resistance of 2.2×10−7 [higher than copper] and conductivity of 4.55×106 [lower than copper].  Tin has a resistance of 1.09×10−7 [lower than copper] and conductivity of 9.17×106 [higher than copper].  As an alloy these qualities are averaged [for the most part] as per the alloy composition.  A 65/35 solder has almost the same resistance and conductivity as copper but a higher melting point than 60/40 which is probably why 60/40 is more popular.  Still, the difference between the two is almost immeasurable and definitely can't be heard through the few connections we make in our cables.

 
Um... are you neglecting the power factor on those numbers? Both lead and tin are much much worse the copper. Only silver is more conductive than copper.
 
You also can't really calculate equivalent resistivity by simply averaging from the composition. (and conductivity is simply the reciprocal of resistance)
 
Mar 4, 2015 at 6:16 PM Post #3,614 of 10,535
 
A lead tin alloy solder actually has almost the same resistance and conductivity as pure copper wire.  You can look up the individual metals base measurements here: http://chemistry.about.com/od/moleculescompounds/a/Table-Of-Electrical-Resistivity-And-Conductivity.htm
 
As you can see, Copper has a resistance of 1.68×10−8 and conductivity of 5.96×107.  Lead has a resistance of 2.2×10−7 [higher than copper] and conductivity of 4.55×106 [lower than copper].  Tin has a resistance of 1.09×10−7 [lower than copper] and conductivity of 9.17×106 [higher than copper].  As an alloy these qualities are averaged [for the most part] as per the alloy composition.  A 65/35 solder has almost the same resistance and conductivity as copper but a higher melting point than 60/40 which is probably why 60/40 is more popular.  Still, the difference between the two is almost immeasurable and definitely can't be heard through the few connections we make in our cables.

 
I think you need to break out the calculator and see how negative exponents factor into what you're saying. Algebra FTW. 
 
1.68x10^-8 is the same as 0.0000000168, while 1.09x10^-7 is   0.000000109.  See the difference?
 
The resistance of tin is in fact 6.488 times larger than copper, using the numbers you provided. Solder does not have the same conductivity as pure copper. Choosing to not make a good mechanical connection is a big no-no. Not only will you end up with a weaker joint, but a worse connection. To what extent? Well that depends. 
 

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