Wire for solder termination - Page 1
Forum section: electronics / general

author: Harvs
author_rank: Super Contributor
timestamp: October 14, 2016, 10:51:27 pm
content: I was thinking today there must be an answer to this that has alluded me for years.Is there a type of wire (or insulation more specifically) that is designed for solder termination?What I'm getting at, is your typical hookup wire that everyone sells with PVC insulation, when the end of it is brought up to soldering temps the insulation melts away from the joint area.

author: KL27x
author_rank: Super Contributor
timestamp: October 15, 2016, 08:37:31 am
content: Solder doesn't even adhere through a molecular layer of oxidized copper. Even if the insulation melted at soldering temp, what kind of flux do you need to get through 2 mils of melted insulation? The wire would also wick heat from the joint. What happens to that part of the insulation? What happens when temp approaches 150C and wires rub together, is the insulation still going to hold up?Some insulations seem to shrink away from the heat of soldering, pulling back and exposing more wire than you wanted. If they could fine tune that property it might work ok.

author: Harvs
author_rank: Super Contributor
timestamp: October 15, 2016, 09:15:55 am
content: I'm not talking about soldering though the insulation, rather as you said the insulation shrinks back from joint. I was thinking that their might be a wire insulation type that doesn't shrink back during normal soldering, and can stand up to normal soldering temps.

author: peter.mitchell
author_rank: Super Contributor
timestamp: October 15, 2016, 10:26:24 am
content: High temp insulation and insulation that burn rather than melt are suitable for this purpose. Silicone rubber is one example of this.

author: cowana
author_rank: Frequent Contributor
timestamp: October 15, 2016, 10:30:19 am
content: PFTE insulation is typically used on aircraft installations - it doesn't melt, burn or decompose in heat (meaning a fire won't cause a risk of shorting). It's a real pleasure to work with - the 'shrinking back' of PVC insulation when soldering is really nice to get away from!

author: SeanB
author_rank: Super Contributor
timestamp: October 15, 2016, 12:14:50 pm
content: 2 types are solid PTFE and foamed PTFE, both of which are fine at soldering temperatures, and which can even be soldered immersed in molten solder. Sadly both very expensive and somewhat toxic when you do get to the char point.Another is silicone rubber, with or without a glass woven sleeve over it, and you get mains cabling with a silicone rubber heath and a double cotton cover iverweave on it, with the lot woven into another cotton oversheath with cotton fillers to make it round.

author: Kean
author_rank: Unknown
timestamp: October 15, 2016, 05:51:28 pm
content: Silicone rubber tends to be commonly used on the larger diameter wire and cables, and PTFE insulation on the smaller diameter. Often PTFE is required in high-end equipment (aviation/military) for extreme temperatures, and silicone rubber for industrial for abrasion/chemical resistance and flexibility.Both are generally quite expensive, and PTFE can be tricky to strip without a good stripping tool. Also, the PTFE insulation is often quite thin, so I've found the wires can get surprisingly hot during soldering and I've burnt my fingers a few times. I recommend soldering with a vise or "helping hands" holding the wires if you don't already.