One of the things you find yourself doing as a young engineer is equipping yourself with the tools of your trade. These will be the foundations upon which your career is built in a way that a diploma or degree certificate will never be, for the best degree in the world is less useful if the quality of your tools renders you unable to capitalise upon it. You may be lucky enough to make some of them yourself, but others you’ll lust after as unaffordable, then eventually put the boat out a little to buy at the limit of your meager income.
Your bench may have a few of these lifetime tools. They could be something as simple as screwdrivers or you may have one of those indestructible multimeters, but in my case my lifetime tool is my soldering iron. At some time in 1992 I spent about £60($173 back then), a lot of money for a student, on a mains-powered Weller Magnastat. The World Wide Web was still fairly fresh from Tim Berners-Lee’s NeXT in those days, so this meant a trip to my university’s RS trade counter and a moment poring over a telephone-book-sized catalogue before filling in an order slip.
The Magnastat is a simple but very effective fixed-temperature-controlled iron. The tip has a magnet on its rear end which holds closed a power switch for the heating element. When the tip has heated to the Curie temperature of the magnet, it loses its magnetism and the switch opens. The temperature falls to below the Curie temperature and the magnetism returns, the switch closes, the tip warms up again, and the cycle repeats itself. The temperature of the tip is thus dictated by the magnet’s Curie temperature, and Weller provides a range of tips fitted with magnets for different temperatures.
The result is an iron with enough power to solder heat-sucking jobs that would leave lesser irons gasping for juice, while also having the delicacy to solder tiny surface-mount components without destroying them or lifting tracks. It’s not a particularly small or lightweight iron if you are used to the featherlight pencil irons from today’s soldering stations, but neither is it too large or heavy to be unwieldy. In the nearly quarter century I have owned my Magnastat it has had a hand in almost everything I have made, from hi-fi and tube amplifiers through radio transmitters, stripline filters, kits, and too many repairs to mention. It has even been pressed into service plastic-welding a damaged motorcycle fairing. It has truly been a lifetime tool.
You only really get the measure of a supplier or a piece of equipment when something goes wrong, and thus we come to the incident that prompted this review. A couple of weeks ago, inconveniently while I was building a microcomputer kit, the magnet on my iron’s tip failed. It’s inevitable that this will happen to a magnet subjected to continuous high temperature, and it’s a known failure mode for Magnastat irons. When it happens the heating element is left on continuously and the tip temperature skyrockets. Eventually you notice the tip is glowing a soft red, and you know it’s time for a new tip.
It’s worth taking a moment to look at the tip that failed. On the right is a picture of two tips, the upper one is a brand-new tip and the lower is the 25-year-old one with a dead magnet. You can see the extra oxidation on it from its final moment of extreme heat.
I had never really considered the condition of my iron’s tip until I removed it. As you can see it is still exactly the same shape as it was when it was made, there is no pitting or recession. When you consider that this tip has seen over two decades of use, that is remarkable. It’s a long time since I used a cheap iron on a regular basis, but one of the things I remember about them was the tendency of their tips for erosion. Perhaps the condition of my iron’s tip is due to my use of decent quality solder and flux, but even so had I thought about it I would not have expected it to have lasted this well.
Replacing a Magnastat tip is a simple task. There is a knurled nut at the base of the tip which you unscrew, then withdraw the old tip before dropping in the new one and returning the nut. Despite a lifetime of heating and never having been undone before the nut undid readily without extra tools, another unexpected bonus.
So, I ordered a couple of new tips – might as well have more than one tip shape – and fitted one to the iron. Job done, you might say, except it isn’t quite. There is a snag, even though I’ve spent the majority of this article praising the Magnastat to the skies as one of my most useful and reliable tools.
I said earlier that you only really get the measure of a supplier or a piece of equipment when something goes wrong, and I’ve examined in detail the piece of equipment. How about the supplier?
Weller have made Magnastats for decades and they are still a significant part of their range. They make a large selection of replacement tips for Magnastat irons both young and old, in the system’s various different formats. If you have an older Magnastat as I do, you can buy all the tips you could when it was first made.
Unfortunately it is difficult to escape the impression that Weller do not want to make life easy for owners of their older products. All their tips are listed in detail, but with a glaring omission. When they list which irons the tip is compatible with, they only list the models in their current range. Owners of older models are left to guess, phone a friend, or fruitlessly search the Internet. It’s something of a surprise that this would have been an easier process back in 1992, then I’d have taken my old tip to the trade counter and the guys there would have brought out a selection of stock for physical comparison. The Internet has done wonders for product availability, but it’s not quite bridged that gap. In the end I solved my problem with the help of friends, I’m not the only person in my circle with an older Magnastat, and eventually we identified the current tip range that would fit my iron.
There are a handful of manufacturers who make products that are legendary for lasting forever, and who still support their products made a lifetime ago. These are usually those who set the standards in their field, and whose products are synonymous with what they do. People buy them even though they cost more than some of their competition because they know they will get the best product available, and they are unlikely to ever have to buy another one.
Weller I would have said are one of those companies. There are other soldering irons, there may even be better or more expensive soldering irons. If you buy a Weller though, I would have said, you can consider yourself to have solved your soldering problems, you may never have to buy another iron.
The trouble is, given my recent experience I now can’t quite put Weller completely in that category. They make great irons that last forever and they make tips for aged irons, but such a crucial and simple piece of the puzzle as maintaining the compatibility information that links the two is missing. If I could sit down in front of the boss of Weller in his office in Germany I’d suggest he rectify that situation. It needn’t be a difficult task, he could simply give a lucky summer intern a big name on their résumé by sitting them down with a spreadsheet and a big box of tips and old irons. If he did that, he’d be certain to reap the benefits as grizzled old engineers with decades-old irons extol the virtues of their new-found support to the ironless young buyers.
So if you are looking for a soldering iron, I can heartily recommend the Weller Magnastat as one that will last you a lifetime. Mine has, and so have those owned by countless other engineers. I’d buy another one without a second thought, they are that good. If your Magnastat tip eventually fails you needn’t worry about whether a new one will be available, though identifying which one fits your iron may for now be something of a challenge. Don’t let that put you off, you won’t be the only person who has faced this issue.