Roll my sleeves up - Page 1
Forum section: electronics / general

author: PerranOak
author_rank: Frequent Contributor
timestamp: July 04, 2025, 02:09:06 pm
content: Whenever I do a botch ... I mean patch, the wire I use (standard single core with PVC sleeve) suffers sleeve shrinkage.Usually it's ok as I can position it to avoid shorts but is there a more heat-tolerant solution for simple patch wires?Cheers.

author: fourfathom
author_rank: Super Contributor
timestamp: July 04, 2025, 03:30:51 pm
content: Kynar insulated wire-wrap type wire (#30 gauge) can be found, and is quite heat-resistant. I don't know about heavier gauges though.

author: edavid
author_rank: Super Contributor
timestamp: July 04, 2025, 03:40:20 pm
content: Kynar wire is great if 26AWG or 30AWG solid wire will work. Otherwise, there are different types of PVC that are a tradeoff between flexibility and shrinkback.UL-1007UL-1061 insulation has very little shrinkback, but other UL rated types seem pretty good too. It seems like there should be a chart that covers this, but I can't find one.It might be worth calling a wire manufacturer for advice, or you could just order short lengths of a few different wire types from a distributor that sells it by the foot/meter and see what you like.(And what's the UK/EU equivalent of UL rated wire?)

author: Kean
author_rank: Unknown
timestamp: July 04, 2025, 03:46:50 pm
content: I typically use Kynar (PVDF) insulated wire-wrap wire unless high currents (for 30AWG) are involved.Otherwise I keep some Teflon (PTFE) insulated wire handy as it has a much higher temperature resistance than PVC insulation, but it is a bit of a pain to strip compared to PVC so I often don't bother with it.Edit to add: also if you'd like to stick with PVC, then look for irradiated PVC insulation which makes it more temperature resistant - but will be a bit harder to find and more expensive.

author: Kean
author_rank: Unknown
timestamp: July 04, 2025, 03:55:11 pm
content: Quote from: edavid on July 04, 2025, 03:40:20 pmProbably "Tri-rated" wire which means it conforms to UL, CSA, and BS standards. I've come across it while buying from Farnell or RS.Some example hook-up wire categories from a UK wire stockist:https://ksm.co.uk/cables/equipment-and-hook-up-wires/

author: fourfathom
author_rank: Super Contributor
timestamp: July 04, 2025, 03:56:14 pm
content: You might also look into silicone-insulated wire. This comes in heavier gauges.

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2025, 03:59:59 pm
content: Quote from: edavid on July 04, 2025, 03:40:20 pmDo you use a specific brand of UL 1007 wire? As far as I can tell, the UL 1007 style does not have any shrinkback specifications, and the UL 758 standard that the 1007 definition refers to doesn’t either, for PVC.I have definitely used some wire that is labeled UL 1007, but had significant shrinkback. But it wasn’t a high-quality brand.

author: langwadt
author_rank: Super Contributor
timestamp: July 04, 2025, 04:01:15 pm
content: solderable enamelled wirehttps://www.wires.co.uk/acatalog/sx_ec_wire.htmlstripping done by dipping the cut end in a blob of solder on the iron

author: edavid
author_rank: Super Contributor
timestamp: July 04, 2025, 04:09:53 pm
content: Quote from: tooki on July 04, 2025, 03:59:59 pmOK, I blew it. I was actually thinking of UL-1061 "semi-rigid PVC", but that is not easy to find at all. What I have came from Atlas Wire. I also have some UL-1007 that is OK, but I don't know the brand.Has anyone tried "XLPE" hookup wire?

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2025, 04:33:17 pm
content: Quote from: PerranOak on July 04, 2025, 02:09:06 pmI really like polyolefin-insulated wire like Huber+Suhner Radox 125 and Helukabel Helutherm 145. But unfortunately it isn’t made in anything thinner than 24AWG/0.25mm2, stranded.By single-core, do you mean solid wire?Anyhow, you can easily get wire (both stranded or solid) with silicone or Teflon insulation. Silicone is completely resistant to soldering temperatures, and Teflon is much better than PVC.What’s also really nice for bodges* is solderable enameled magnet wire. It must be the solderable kind (= enamel that degrades below soldering iron temperatures), otherwise you either need to strip it first, or use extremely high temperatures to burn off the enamel. For example, Farnell ECW0.224 (0.224mm) or ECW0.4 (0.4mm), which have 180 degree-rated polyurethane, and whosedatasheetdescribes it as being for use with automated soldering equipment. You just hold it in the solder blob of the joint and the enamel burns off. Then you can use a scalpel to cut off the part you don’t need. Also, it’s incredibly inexpensive.*botch = to mess up; bodge = to patch, repair

author: Kean
author_rank: Unknown
timestamp: July 04, 2025, 04:50:40 pm
content: Quote from: edavid on July 04, 2025, 04:09:53 pmYes, I believe this is quite similar in properties to the irradiated PVC as I mentioned above.The insulation is slightly stiffer after irradiation but the cross-linking makes it effectively thermoset instead of thermoplastic.I use pre-crimped wires from Molex which uses Sumitomo UL1571 style wire which the datasheet says isXLPEXLPVC, but probably is irradiated PVCconsidering it is branded "IRRAX V2".I find it is a bit better than standard PVC, but nothing special in my experience. Still only intended for 80°C max applications.Years ago I tried sourcing it for a customer and MOQ was 12km per colour, which was a bit much for their use.

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2025, 05:15:49 pm
content: Quote from: Kean on July 04, 2025, 04:50:40 pmThe datasheet says “XLPVC” right at the top in a little blue oval:https://global-sei.com/ewp/E/products/detail/pdf/1_1571.pdf(See also: the delightfully Engrish last chapter of the complete catalog:https://global-sei.com/ewp/E/products/detail/pdf/all.pdf)

author: Kean
author_rank: Unknown
timestamp: July 04, 2025, 05:45:20 pm
content: Quote from: tooki on July 04, 2025, 05:15:49 pmOK, that has changed since the 2008 version of the document I had on file which has PVC, Halogen Free, and XLPE in ovals.But I now realise that the light blue ovals do not apply, only the dark blue ovals.My bad... but it does confirm my suspicion of irradiated PVC.The description of irradiation in the catalog does explain the advantages in great Engrish detail.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 04, 2025, 11:37:02 pm
content: I upvoted both silicone insulated and "enameled" wire. Silicone is usually for supple multi strand wire, and can be quite thick. "enameled" wire can be used with an "extra hot" iron (350c or so) to burn off the lacquer and once it's tinned it can be soldered at regular copper wire.I have used enameled wire quite a lot. This stuff has been used ever since the '70-ies such as with the "roadrunner" prototype wiring system. For some "vintage" usage, you can have a look at the old BBC micro as modified by mikeselectricstuff. It may look funky, as the laquer is stransparent and quite thin, but in practice it really is quite reliable and has a long service life. I have buit some DIY systems this way which have been running for 20 years and still work just fine. After building and initial testing I do add a few dabs of glue to hold the wires in place against vibrations and such.The Teflon / Kynar insulated wire can also be used. Melting point of the insulation is above soldering temperature, so no melting or shrinking at all. but the insulation is quite tough so you need good quality tools to strip the wires. With the "enameled" wire, you don't need to strip the wires at all.