Connecting non-solderable wires

[HANKMARS]

I can foresee this ending in a complete mess.
Just use a crimplink or a ceramic terminal block and be done with it.

Using a crimp link may be too cumbersome trying to get a quality crimp tool in close quarters. Also, I have a bias towards using crimp on lugs on solid wires. Due to the low temps of this application, ceramic material would not be unnecessary. Terminal blocks are too bulky for the space available.

 

[Bluejets]

Crimping solid wire is done everyday with no problems, regardless of other opinions.

 

[duke37]

Silver solder needs a blow torch to get sufficient temperature. I wonder how the cost compares with a mechanical connector.

 

[HANKMARS]

Crimp link.

Well, I have come back to a crimp link. I put the wires through the link, bend the end over, then crimp, then fill the void with 60/40 tin/lead solder. That is the best method I have found yet. I tried to do a copper plating on end to be soldered but the copper did not adhere well to resistance wire. The heatshrinkable butt connectors did not make a reliable connection plus they required too much extra length of wire. So here I am.

 

[Technomaniac]

I have a workshop with a 24 v Weller soldering iron on every bench. Inside the iron, (from new, factory) are twisted joints with metal-free screw connectors screwed over the twisted joint. These "connectors" are all plastic,no metal, and have an internal screw thread which is tapered. You insert your twisted joint into the tapered hole, and screw the all plastic "connector" on to the twisted wires. The connections are very reliable. OR, IF IT WAS WORKING, I would use my mini-spot welder.

 

[HANKMARS]

I have a workshop with a 24 v Weller soldering iron on every bench. Inside the iron, (from new, factory) are twisted joints with metal-free screw connectors screwed over the twisted joint. These "connectors" are all plastic,no metal, and have an internal screw thread which is tapered. You insert your twisted joint into the tapered hole, and screw the all plastic "connector" on to the twisted wires. The connections are very reliable. OR, IF IT WAS WORKING, I would use my mini-spot welder.

Thank you for your suggestion. The connector you are describing sounds to be what I refer to as a "wire nut." If it is indeed what I think it is, they come in a wide variety of sizes. I use large ones for house wiring, motor connections to power input lines, etc. Unfortunately the connectors will prove to be too bulky for my restricted area. I need to make up 10 connections in the interior of a heated hand glove. I am connecting nichrome wire ( resistance wire ) to copper power wires, 22 ga. I am having good performance from a connection technique that I have developed. I will try to post a photo of a real connection soon. The connection itself needs to withstand much movement as they are made up between the knuckle and second hinge joint from the tip of each finger. Since spring has arrived, the heated clothing is on a back burner while I tackle the problems of cooling clothing. Thanks again. PS The connection in the existing photo was too bulky and unreliable.

 

[Technomaniac]

Minimum bulk = mini spot welder. The charge in a big capacitor is dumped into the welding contacts.

 

[Bluejets]

Low temperature silver solder will work for less bulk than a crimp.

This is NOT your everyday 60/40 tin lead.

Cadmium bearing is best, the other one has to poke and putty the joint, no flow like the former.

Would be a costly exercise though for a couple of joints.

I doubt spot welding is going to work with multicore flex wire and nichrome.

 

[HANKMARS]

Minimum bulk = mini spot welder. The charge in a big capacitor is dumped into the welding contacts.

I will be trying to fuse copper wire, 22 gauge stranded, to nichrome wire, 22 gauge solid, Melting point of nichrome is approximately 2550 degrees F, melting point of copper is approximately 1980 degrees F. Is this difference of nearly 600 degrees in melting points going to be a problem? I don't have the data in front of me but I'll guess that an electric arc produces temperatures of 5000 degrees F and higher.

 

[HANKMARS]

Low temperature silver solder will work for less bulk than a crimp.

This is NOT your everyday 60/40 tin lead.

Cadmium bearing is best, the other one has to poke and putty the joint, no flow like the former.

Would be a costly exercise though for a couple of joints.

I doubt spot welding is going to work with multicore flex wire and nichrome.

I have considered trying silver solder but have not yet attempted it. What is ballpark temp required for silver soldering? I do recall that MAPP gas was required for the silver soldering. Regarding cadmium; is that a silver solder laden with cadmium? I seem to recall that cadmium is very toxic.

 

[Technomaniac]

And Cadmium grows whiskers, which are conductive,and can be a problem. We have had problems with wavechange switches in the vintage AM radios. The shaft through the centre of the wafers of the switch is cadmium plated and grows whiskers which grow all the way across to the moving contacts and short circuit them to ground. We're not talking LEAKAGE, we're talking DEAD SHORTS.Low resistances. I have low temp silver solder, not sure it uses cadmium.But don't think there was much info came with it. Most of my silver soldering is done with a little gas torch, using silver alloy rods and separate flux which has borax as its main ingredient. It produces some very neat joints. Regarding temp for the low temp silver solder, my Weller irons use the 800 deg F = 425 deg C tips as we found them better for soldering tarnished fractured joints on PC boards, which is where they were most used.But I have tried the low temp solder only once, haven't needed to use it.