Soldered splices

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iwire

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Location
Massachusetts
mdshunk said:
I want a refund.

Just send me your bank acount number, I will send it right out.
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rattus

Senior Member
I think he said:

I think he said:

iwire said:
You will have to explain to me how the line gets shorter when the conductors are twisted.

The length of the "twist" would be shortened as the twist is made tighter, but the length of the contact area would not change, however the width would be increased and hence the contact area would increase.
 

rattus

Senior Member
don_resqcapt19 said:
rattus,

Actually the resistance goes up a bit. The solder completly covers the copper and has a higher resistance than does a solid copper to copper contact.
Don

Well maybe, but I would think the solder would not wick into the contact areas. In plumbing joints there is a mil or so of clearance between the surfaces.

Maybe someone has the equipment to check this out.
 

rattus

Senior Member
I have:

I have:

georgestolz said:
Can I see a show of hands of who here has soldered wires before?

I, for one, have not.

I did, about 50 years ago. Once as a helper, and another time wiring a farmhouse where no license or permit was required. Used a gasoline fueled blowtorch and a big fat soldering iron. Wrapped them with rubber tape and then covered that with friction tape. Wirenuts would have been much easier.

Oh, many times on electronic circuits, but that doesn't count!
 

Smart $

Esteemed Member
Location
Ohio
rattus said:
Smart, the copper compresses somewhat when twisted, and this provides the contact area.
That is correct... neglected to put that in there. But it should be noted that while there will be contact "area", that area will be comparatively small to the conductor's surface area. I wonder how much relative length would have to be twisted to achieve a contact area equal to each conductor's cross-sectional area...?

rattus said:
It is logical that solder would increase the contact area and therefore reduce the resistance, but the change would be small.
Agreed. Yet wouldn't the significance be in direct proportion to the current passing through the connection? Measurements are usually taken at quite low current levels and therefore would belittle the significance.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
I have soldered 10, 12, and 14 ga machine tool wire, for use in the 'submarine' project. I have also worked with soldered connections up to 6ga used in electric motors (others doing the soldering). Properly done, I don't think that soldering these splices would cause any significant problem for the modern insulating materials used in building wire. I have never soldered building wire for building wire use, but I have soldered stranded and solid copper wire of the appropriate gauge.

The large wires call for lots of heat if you want to do the splices quickly and not damage the insulation.

My _guess_ (I have not done this) is that if the splices are done using a 'solder pot', then the makeup would be very rapid indeed. The solderpot provides a reservoir of lots of heat.

If the use of 'crimp sleeves' for soldered splices is a listed application, then this process would be nearly as fast as using wire-nuts, possibly faster than wire-nuts with pre-twisting. I had never heard of this use of 'crimp sleeves' before, and it is possible that it was a technique that was not really approved, or which used special sleeves that are no longer available, or which works just fine with available sleeves. If you can use crimp sleeves followed by a solder pot dip, then the insulating caps sold to go over the splices may still be acceptable for insulating the splices. This would eliminate all of the delay caused by having to tape and insulate the splices.

Good luck selling the sizzle!

-Jon
 

Smart $

Esteemed Member
Location
Ohio
not exactly

not exactly

rattus said:
The length of the "twist" would be shortened as the twist is made tighter, but the length of the contact area would not change, however the width would be increased and hence the contact area would increase.
When you twist two wires, the path of contact is a straight line through the center of the twist (mind you, in a perfect scenario). Twisted wires are shorter in length than their straight version counterparts. Hence, the line is shorter.
 

iwire

Moderator
Staff member
Location
Massachusetts
Smart $ said:
When you twist two wires, the path of contact is a straight line through the center of the twist (mind you, in a perfect scenario). Twisted wires are shorter in length than their straight version counterparts. Hence, the line is shorter.

The line itself, the contact area, will not be shorter, which is what you seem to be saying here..

Smart $ said:
Twisting does not increase the contact "area" for the same length of wire. In fact it reduces the "line" length.
 

allenwayne

Senior Member
mdshunk said:
No, we actually had a conversation about it. He is able to present this to the potential buyers as one feature that makes his homes superior to others. Whether this is actually true or not is another story. Perception is reality; sell the sizzle not the steak; etc., etc.

I'm actually anxious to do a solder job just to say I did one (or several). Kinda like paying homage to the electricians of yesteryear. Reminds me of a saying a plumber once told me:


A hundred years from now, they will gaze upon my work and marvel at my skills but never know my name. And that will be good enough for me.
-Dan Holohan.


I leared the trade from a guy that tought me how to splice and solder.Heck thet shows how old I am.Or how long I`ve been in the trade.
 

Smart $

Esteemed Member
Location
Ohio
iwire said:
The line itself, the contact area, will not be shorter, which is what you seem to be saying here..
The contact area will be the same length as the twisted conductors. Through deformation of the copper the contact area approximates a helical surface, therefore having width. The length along the outer edge of that surface would be longer than at its center, the axis. However, the axial length is the dimensional length. Note width is exaggerated in the following image.

View attachment 244
 
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macmikeman

Senior Member
If you ever drove around that circular toll road in Orlando FLa, you drove over some "Heliax" connectors that I did that had to be soldered per manufacturer's specifcations and training. That was a fun project that got me away from home for a few months. For any that do not know what is Heliax, think antenna wire. There are imbedded antenna's in the pavement for the Epass system.
 

iwire

Moderator
Staff member
Location
Massachusetts
Smart $ said:
The contact area will be the same length as the twisted conductors. Through deformation of the copper the contact area approximates a helical surface, therefore having width. The length along the outer edge of that surface would be longer than at its center, the axis. However, the axial length is the dimensional length. Note width is exaggerated in the following image.

That is all very nice, but is not what you had said.


Smart $ said:
Twisting does not increase the contact "area" for the same length of wire. In fact it reduces the "line" length.

Twisting does not reduce the length of the line.
 

Smart $

Esteemed Member
Location
Ohio
iwire said:
That is all very nice, but is not what you had said.

Twisting does not reduce the length of the line.
For clarity, "area" in the second quote of your post is the line.

And yes, twisting does reduce the length of the line.

As I said before, the contact line is the center of the twist, i.e. axial line. The centerlines of the wires form a two-strand helix about the axial line. The following example makes a relative comparison of those lengths.

View attachment 245

[edit: note triangle is not to scale]
 
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iwire

Moderator
Staff member
Location
Massachusetts
A lot of flash and still no direct answer.

You chose to be 'picky' in this thread so I am just being picky with you.

You clearly indicated in post #31 that "the line" would get shorter. Well the 'line' does not get shorter; it is simply in another shape.

Smart $ said:
Twisting does not increase the contact "area" for the same length of wire. In fact it reduces the "line" length. Twisting does however provide additional mechanical strength to the joint.

So what was it you where trying to say in post 31?

You don't have to open your graphics program for this question.
 

rattus

Senior Member
Nuh-uh!

Nuh-uh!

Smart $ said:
As I said before, the contact line is the center of the twist, i.e. axial line. The centerlines of the wires form a two-strand helix about the axial line. The following example makes a relative comparison of those lengths.

The length of the contact is the length of the wire in the helix, not the axial length of the helix.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
So far, in my informal poll, for those of you following along at home:

Soldered in building wiring (as infant included):
Rattus, Allenwayne, Flick, e57, Don_Rescapt19, MacMikeman, Smart $

Soldered in electrical applications other than building wiring:
Iwire, Winnie, MacMikeMan, JJHoward, Tallgirl, Smart $

No soldering experience (or words to that effect):
Georgestolz, MDShunk, Infinity,

No comment:
 
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roger

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Staff member
Location
Fl
Occupation
Retired Electrician
iwire said:
A lot of flash and still no direct answer.

You chose to be 'picky' in this thread so I am just being picky with you.

You clearly indicated in post #31 that "the line" would get shorter. Well the 'line' does not get shorter; it is simply in another shape.



So what was it you where trying to say in post 31?

You don't have to open your graphics program for this question.

She may prove me wrong, but I doubt you get a direct answer from her Bob.
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Roger
 

Smart $

Esteemed Member
Location
Ohio
rattus said:
The length of the contact is the length of the wire in the helix, not the axial length of the helix.
Afraid not.

As you noted previously, "the copper compresses somewhat", or something quite similar. Wire deforms when it is bent: the inner portion compresses, the outer portion stretches, while the centerline remains relatively the same (you'll find this somewhat true also when bending conduit, the difference results mostly from the hollow core). Just on that fact alone the length of contact is shorter.

Now add the fact that the wires meet at an angle all the way along the twisted section. Evaluate the contact line as the accumulation of points centered between transverse points on wire centerlines.
 
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