Thin flexible 3-core mains flex for Solon

[Phil G4SPZ]

I managed to damage the (rather lengthy) mains lead of my trusty Henley Solon last week. Fortunately, the lead was long enough to be re-used after cutting away the damaged portion and re-terminating it at the iron. The upside is that the earth lead resistance is now down to under 0.2 ohm, where it was previously 0.26 ohm with the full length flex.

However this raises the question whether such relatively thin, 3-core mains flex is still available, particularly with a nice flexible sheath. I didn’t measure the wire gauge but I expect it is less than 0.5 sq mm. The sheath is 4.3mm diameter.

If anyone can recommend a reasonable source of such flex, it would be much appreciated.

[McMurdo]

I'm sure I learned that 0.5mm is the minimum allowed for connection to a 13A plug. You can buy pre-cut lengths of silicone high-flex burn-resistant mains cable for soldering irons on ebay...at least when I last looked.

We had the solons at college and one of our first jobs at the start of the term in electronics class was replacing all the burned mains leads, and I did notice how thin (and melted!) they were.

The lecturer produced a reel of 1.5mm white appliance flex (the sort of thing you'd have on an immersion heater!) and asked us to fit that. Not only did it make the irons impossible to manipulate but the flex would not go through the tiny rubber boot/grommet affair on the solon. He simply told us to discard it, thus the irons lost their strain relief too!

And that was in electronics!



ps: heres an ebay link, I have no experience of this supplier.

https://www.ebay.co.uk/itm/323951341...SABEgKU8fD_BwE

[Boulevardier]

I think Kevin is right. My old 25W Solon also has a very thin mains cable that just doesn't seem to be available any longer. My much newer 15W and 25W Antex's have leads that could probably happily feed a 500-1000W load (which makes these "miniature" irons ridiculously unwieldy and difficult to use).

I assume this is down to any lead carrying 230V being required to have a minimum physical protection/insulation level, regardless of the tiny current it may be carrying. But it does make a nonsense of tools designed for delicate work.

Mike

[Phil G4SPZ]

Thanks, Kevin! I suspect it’s coming from China, as I couldn’t find any UK suppliers. But I’ve taken the plunge and ordered a couple of metres of the 0.3 sq mm for stock. Whether it’ll fit through the Solon’s boot remains to be seen! Fingers crossed…

I agree, Mike. My elderly 15 watt Antex has a very flexible lead too.

Among my favourite small irons are the “Oryx” 12-volt precision types. I have a 9-watt and a 12-watt model and they perform remarkably well. These have very thin 2-core leads little thicker than bell flex. Makes the iron really light and easy to handle.

[G6Tanuki]

You can get 'high temperature' cables from the usual electrical/plumbing-trade outlets; there are 3- 4- and 5-core versions available, it's used for wiring the control electrics of central-heating boilers.

[Phil G4SPZ]

As far as I could see, the smallest available conductor size is 0.75 sq mm which makes the cable far too bulky for a 25-watt soldering iron.

[Reelman]

The thicker wire supplied with modern mains irons does certainly make them unwieldy and in my opinion more dangerous as the weight of the cable can drag a hot iron across the bench…
The Servicescope Minor oscilloscope had ideal thin cable which I have certainly requisitioned in the past for my Antex. Funny, if you need to replace the element or cable on an Antex you need another iron.

Shoot me down in flames here but….
Thin 2 core screened microphone cable can be pretty thin. If rated for 250V would anyone use it?

Peter

[David G4EBT]

You can buy replacement black 3-core silicone flex for Antex, irons which would I think do just as well.

Rapid stock it:

1.5 Metres (5ft), 6mm diam, stripped and pre-tinned:

https://www.rapidonline.com/antex-re...ng-irons-30215

[G6Tanuki]

Originally Posted by Reelman

Shoot me down in flames here but….
Thin 2 core screened microphone cable can be pretty thin. If rated for 250V would anyone use it?

Peter

Call me a sinner, but in times-past I used an ex-telephone-handset curly-cord on a mains soldering-iron. And the same [with multiple cores in the curly-tinsel paralleled] was also used by plenty of exchange-types to run their soldering-irons off the standard 48V DC supplies.


I'm still alive. Tinsel wire survives OK at low current....

[Tim]

We had the solons at college and one of our first jobs at the start of the term in electronics class was replacing all the burned mains leads, and I did notice how thin (and melted!) they were.

The lecturer produced a reel of 1.5mm white appliance flex (the sort of thing you'd have on an immersion heater!) and asked us to fit that. Not only did it make the irons impossible to manipulate but the flex would not go through the tiny rubber boot/grommet affair on the solon. He simply told us to discard it, thus the irons lost their strain relief too!

You were lucky! We were simply instructed to wrap any burns in the flex with "insulation" tape. I do recall the lecturer complaining about the amount of tape we had used.

[lesmw0sec]

Originally Posted by Reelman

The thicker wire supplied with modern mains irons does certainly make them unwieldy and in my opinion more dangerous as the weight of the cable can drag a hot iron across the bench…
The Servicescope Minor oscilloscope had ideal thin cable which I have certainly requisitioned in the past for my Antex. Funny, if you need to replace the element or cable on an Antex you need another iron.

Shoot me down in flames here but….
Thin 2 core screened microphone cable can be pretty thin. If rated for 250V would anyone use it?

Peter

That reminds me of an incident in Ch.9 Brisbane. We were tidying up a rack and found a screened audio cable with the end taped. Curious to know what it went to, my colleague untaped it and promptly got a belt. It was mains! We could not locate the other end, so insulated it and applied a label saying: Caution - +50 dBm at 50 c/s!

[Station X]

Originally Posted by Phil G4SPZ

I’ve taken the plunge and ordered a couple of metres of the 0.3 sq mm for stock.

The OP has ordered some new flex, so it's time to close this thread.

[Station X]

Thread reopened at OP's request.

[Phil G4SPZ]

Thank you, Graham.

Sadly, I have to report a bit of a failure. Firstly, the eBay supplier sent 2-core instead of the 3-core I’d ordered, and secondly, the sheath is significantly bigger than the existing flex on the Solon. The 3-core version of the new cable is reputedly 5.3mm in diameter, slightly bigger still than the 5mm 2-core shown in the photo, whereas my old Solon flex measures just 4.3mm diameter. Looking at the relative sizes of the new flex and the old, I doubt whether the cable would even enter the grommet without a great deal of heat, stretching, stress and effort.

I have failed to find a thinner 3-core mains-rated flex anywhere, although David’s suggestion in post #8 looks promising from Rapid Online. I have ordered a 3-core 1.5m Antex cable (a bit pricey at £13.84 including postage) but keeping our old Solons going has got to be worth it!

I use a 110 volt Solon in my workshop at home, and its grommet and cable are distinctly bigger than the 240 volt model.

The moral is to take great care of your Solon and its mains lead!

[Boulevardier]

That’s a real shame Phil, but well done for your efforts. I suppose microphone cable, used with a 250mA plug-fuse together with one of those plug-in RCD thingies, would be perfectly safe.


I get really fed up of using soldering irons fitted with “flexes” thick enough to feed a kettle!


Mike

[Phil G4SPZ]

Thanks, Mike. I hope the thread will remain open for a while longer so that I can report back once the Antex flex arrives.

[ronbryan]

Phil

Probably too late as you have now spent money on the Antex cable, but I can spare a small quantity of RS Components 377-704 0.4sq mm black 3 core pvc cable (cores are modern colours) with an o/d of 4.8mm or 0.190". I should think that would fit in a Solon grommet with a bit of Hellerene as lubricant. I found the empty reel, but remembered that all of the flex on it was fitted to my battery charger, a 10A Coutant open frame power supply. There is 5.5m on the charger mains lead so I could cut 1.5m off and send it to you.

Ron

[Phil G4SPZ]

Hello Ron,

Thank you very much for your kind offer. However, I have indeed ordered the Antex cable, so I won’t need anything from you on this occasion.

Such generosity is so good to see nowadays, although it is something that underpins the whole Vintage Radio movement. Long may it continue!

Thanks again Ron,

[Phil G4SPZ]

Just to round things off, the “Antex W021600 1.5m Silicone Lead” has arrived (very promptly!) from Rapid Electronics but, sadly, it’s even bigger! Lovely cable and very nice and flexible, but its sheath OD is 5.8mm and the conductor size is 0.45 sq mm, comprising 16 twisted strands each 0.19mm diameter. It’s quite heavy too. I can’t see it fitting the Solon and definitely not either of my 15 watt Antex irons.

Thank you for everyone’s suggestions and offers of help, it has been much appreciated.

[Tim]

Hi Phil. I have a gently used( & slightly “foxed*”) 3 m length of 3 core heat resistant cable almost bang on 5mm diameter. About the size of normal 3amp mains flex.

(* Stained but not melted or damaged)
Let me know if you are interested & I can pop it in a padded envelope for you.