TFE (teflon) insulated wire vs silicon insulated wire?

Thread Starter

Wendy

Joined Mar 24, 2008
22,436
My old job used Teflon wire for test fixtures, I loved it. The insulation tends to cold flow under pressure, but was almost impossible to damage or melt with a soldering iron. I was looking at wire on Amazon,but they tended to show silicon insulation instead. I have never used silicon insulated wire. For those in the know how does it compare?
 

SamR

Joined Mar 19, 2019
3,411
Basically it is a high temp rubber jacketing a bit thicker than the typical PVC jacket. Typically on stranded wire and very flexible. Pretty much oil and solvent resistant also. Very popular with the RC crowd. I like to use it for stranded wire applications and jumpers for instrument connections. Keep small spools in several wire gauges and colors on hand. Not quite as tough as the PVC jacketed with the clear nylon overcoat THHN but still good for automotive radio installs.
 

DickCappels

Joined Aug 21, 2008
7,442
It is extremely flexible (at least the stuff I used) and is great for test leads and stuff like that. It won't cold flow and it won't cold flow.
 

SamR

Joined Mar 19, 2019
3,411
I've made a bunch of bench patch cords with banana jacks out of the stuff too. Keep it in both red/black zip cord #16AWG and spooled red and black. I buy this stuff from Amazon to keep on hand in a couple of wire gauges:
1622003806141.png
 

Yaakov

Joined Jan 27, 2019
3,161
Silicone insulation is a lot easier to strip than PTFE. It ends to tear if the stripper is set too large and while that looks less nice it doesn’t have any problems.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,436
I want something that won't melt when soldering, does this describe the silicon insulation? For projects I use 24 Ga.
 

SamR

Joined Mar 19, 2019
3,411
The only drawback to silicone that I can possibly think of would be that it is too flexible. I would not use it prototyping a small perfboard circuit as the wires would flop all over the place and not stay where I wanted them to be routed. There are times where I don't want the wires to move about and would not use silicone.
 

MaxHeadRoom

Joined Jul 18, 2013
23,123
Take a look through the Belden cat. for reference.
I have always used TR64 for hook up wire, and enclosure wiring, tinned 24g (7x32) rated 105C 600v peak rating.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,436
I'm trying to build more dedicated permanent projects, still lots of kinks to work out. so far my solder projects are incredibly ugly.

If at first you don't succeed skydiving is not for you. Soldering can be.
 

MrSalts

Joined Apr 2, 2020
285
The problem with silicone is that it doesn't hold tightly to the wires.

- that is GREAT for flexibility, as are the high wire count of fine gauge strands
- HOWEVER, the many fine wires and loose jacket creates a huge capillary effect and draws solder into the jacket. If you are prone to look for a certain thickness of solder when tinning, you'll definitely get a solder-filled jacket. This is really bad because any movement is of the wire can break the most stressed strand so cable restraints are needed (as most plugs have for banana plugs and other connectors) but do not exist for board to wire connections.
The second problem with silicone jacket wires is one or more of the very fine strands can easily fight your attempts to insert the wire into a through-hole. An easy way to create a short with a neighboring solder pad. The very fine strands are difficult to see.

for a high temp, no melt (low melt) wire, look for crosslinked PVC (XLPVC). Also called irradiated pvc.
The xlpvc with low temp performance (-55C) gets spendy but the stuff for normal temp range is reasonable ($20/100ft).
https://www.digikey.com/en/products/detail/cnc-tech/1430-24-1-0500-001-1-TS/7063277
 
Top