Antex element longevity

PW (Practical Wireless) did an 'iron saver' article which put a diode in series when the iron was in its stand. The 'proper' Antex stands had a heavy spring that touched the bit acting as a heatsink, rather neat.

[SiriusHardware]

I've recently considered using a standard mains dimmer switch control (very cheap now) in conjunction with simple mains irons - like light bulbs, heater elements including those in soldering irons don't really like being slammed straight from OFF to ON. That's when they are most likely to fail.

Disable the switch part of the dimmer so that on / off control of the iron is by turning the knob between minimum and maximum. Even if you do it quite quickly it won't be as vicious as the instant stress caused by flicking on a switch.

This obviously wouldn't be a substitute for a proper temperature controlled iron where the iron monitors its own tip temperature and tries to maintain the temperature over a wide variety of 'loads' - it would just be a more gentle way of bringing the iron up from cold to hot, and vice versa.

The other common cause of element failure is for the iron to be dropped (not to mention the damage it invariably does to the tip if that hits the floor first). I always have the flex of my irons tied to or looped around something at the back of / above the bench with the length carefully measured so that if I fumble the iron or it slips out of the stand, it comes to a halt about about 3 inches short of the floor.

[Andrewausfa]

Thanks for everyones thoughts and responses. I have bought a new CS18 and an element for the XS25 and I'll see how long they last. And I'll keep the receipt!

I did find it most odd that particularly the CS18, which is well used in schools etc and therefore will be left on a lot longer than my own, did not last all that long. Neither iron I had got more than occasional use, just while I'm soldering a repair. Most mystifying was that both went at the same time!

Andrew

[Biggles]

There may be some mileage in the theory that it's the "shock" of sudden switch on that causes the element to fail. Things that are left on for long periods sometimes are more reliable. Like that famous old light bulb that has been running for years.
Alan.

[60 oldjohn]

Would it be possible to use a NTC thermistor to limit the inrush current ? I may add I have never had to replace an iron due to element failure. It is usually seized bits, even though I started using Copper Slip.

John.

[ex 2 Base]

I've got an iron operated via a foot switch,it switches in and out a diode and has worked like this for years, never had to replaced an element. No sudden rush of full load current.Ted

[Techman]

It's certainly a very good question why 'some' of these Antex iron elements fail while others seem to go on forever. This is ONLY an Antex problem it seems - other makes don't seem to suffer from this problem.

It could be a design issue as I think that this is the only soldering iron that has a long, thin element stem with the more substantial tip/bit pushed over it. You know how when unsoldering a component that has its leg wound round a tag and you sometimes tend to use the iron as a lever to unwind the leg from the tag while melting the solder? Well, perhaps this flexes the element stem and eventually causes internal failure. No other irons in common use are constructed like this.

I've just replaced the element in my very old Antex 15 watt iron for the second time (third element) thanks to being able to obtain one from Rob on this forum. It had been out of action for maybe getting on for 40 years. It works very well and I really like the 'sharp' profile of the 'new' older type tip/bit that I also got from Rob, much nicer somehow than the more 'rounded' edged tips of my much newer 25 watt version of the same iron - it seems as hot as the 25 watt iron too, but that's probably just my imagination!

I have a selection (stash) of replacement elements for Antex irons - 25 watt, 18 watt and even some 115 volt versions, but no standard 15 watt elements, so I was pleased to obtain a replacement element, plus a second one for someone else who I know who needed one (I don't know if he's fitted his yet). What I did notice is that the replacement elements are labeled 230 volts, but also my much newer 25 watt iron is also labeled 230 volts - my mains is a solid 245 volts. I've measured the cold resistance of the different elements of the same wattage and found they can differ by up to several hundred ohms for exaxtly the same elements, so there seems to be some 'randomness' in the manufacture. I found this with the two I got from Rob and the ones that I already had that were originally from RS Components. I gave the one with the higher resistance to the other person who wanted one, so if it's a 'mains' issue, then it'll be mine that fails first, though mine should work better while it works. I'll not be giving mine a lot of use as it'll mainly be kept as a spare.

Having said all the above, there's still something special about the 'feel' of an Antex iron, but they must have made a fortune on the sale of new elements over the years!

[avocollector]

I have two mains Antex 25 watters and apart from replacement bits they have gone solidly since the mid 80's - used about once a week for a few hours at most.

[Techman]

I'm wondering if this could be a 'voltage' thing. Where my iron was used in the 70s I remember that I was only one pole away from the electricity sub station. Overhead wires at 3 phase, then a short cable run from one of the phases to the property. I can't remember what the mains voltage was in those days, but being so close to the sub station there wouldn't have been a lot of volts drop.

Where I am now, there's only two other houses between me and the substation. Underground feed and the mains is always at least 245 volts. These Antex irons seem to be rated at 230 volts.

I think what we need to know is the mains voltage at the locations of the posters on this thread. Could it be that those that say they've never had an element fail are on a voltage nearer to 230 volts than those that have had fails?