This video on building a DIY desoldering iron says it all right up front: this is stupid and dangerous, and you shouldn’t do it. But that doesn’t mean it doesn’t work, or that it doesn’t have potential to be turned into something else.
The story begins, as it often does these days, on the pages of Amazon as [AnotherMaker] shopped for a real desoldering setup. Despite a case of sticker shock, he took the plunge on a nice Hakko vacuum desolderer, but as is also often the case, it failed to arrive. Rather than accept defeat, [AnotherMaker] purchased a cheap-o soldering iron and a brass tee fitting for small-bore tubing that would chuck nicely into the spot where the stock tip once lived, giving him a way to both melt solder and move air.
Unfortunately, rather than applying a vacuum, he chose to blast 100 PSI compressed air through the tip, which certainly moves a lot of solder, perhaps at the cost of burns and eye injuries. The potential for accidental short circuits is pretty high too, but c’mon — it’s not like we all haven’t flicked or dropped a board to desolder something. Is this really much different?
A dedicated desoldering station is a fantastic tool if you’re in the business of harvesting components from old gear. Having heat and suction in a single tool is far more convenient than futzing with spring-loaded solder suckers or braid, but only as long as the suction in the desoldering tool has a little oomph behind it. So if the suction on your solder sucker is starting to suck, this simple VFD can help restore performance.
Luckily for [Mr. Carlson], his Hakko 470 desoldering station is equipped with an AC induction motor, so it’s a perfect candidate for a variable frequency drive to boost performance. He decided to build a simple VFD that boosts the frequency from 60-Hz mains to about 90-Hz, thereby jacking the motor speed up by 50%. The VFD is just a TL494 PWM chip gating the primary coil of a power transformer through a MOSFET. Duty cycle and frequency are set by trimmers, and the whole thing is housed in an old chassis attached to the Hakko via an anachronistic socket and plug from the vacuum tube days. That’s a nice touch, though, because the Hakko can be returned to stock operation by a simple bridging plug, and the video below shows the marked difference in motor speed both with and without the VFD plugged in.
My introduction to electronic manufacturing was as a production technician at Pennsylvania Scale Company in Leola PA in the early 1980’s. I learned that to work on what I wanted to work on I had to get my assigned duties done by noon or thereabouts. The most important lesson I had learned as a TV repairman, other than not to chew on the high voltage cable, was to use your eyes first. I would take a box of bad PCB’s that were essentially 6502 based computers that could count and weigh, and first go through inspecting them; usually the contents were reduced 50% right off by doing this. Then it was a race to identify and fix the remaining units and to keep my pace up I had to do my own desoldering.
It worked like this; you could set units aside with instructions and the production people would at some point go through changing components etc. for you or you could desolder yourself. I was pretty good at hand de-soldering 28 and 40 pin chips using a venerable Soldapulit manual solder sucker (as they were known). But to really cook I would wait for a moment when the production de-soldering machine was available. There was one simple rule for using the desoldering station: clean it when done! Failure to do so would result in your access to the station being suspended and then you might also incur the “wrath of production” which was not limited to your lunch bag being found frozen solid or your chair soaked in defluxing chemicals.
[borgartank] is starting a hackerspace with a few guys, and being the resident electronics guru, the task of setting up a half-decent electronics lab fell on his shoulders. They already have a few soldering stations, but [borgar] is addicted to the awesome vacuum desolderers he has at his job. Luckily, [bogar]’s employer is keen to donate one of these vacuum desolderers, a very old model that has been sitting in a junk pile since before he arrived. The pump was shot, but no matter; it’s nothing a few modifications can’t fix.
The vacuum pump in the old desoldering station was completely broken, and word around the workplace is the old unit didn’t work quite well when it was new. After finding a 350 Watt vacuum pump – again, in the company junk pile – [bogar] hooked it up to the old soldering station. Everything worked like a charm.
After bolting the new and outrageously large pump to the back of the desoldering station, [bogar] wired up a relay to turn on the pump with the station’s 24V line. Everything worked as planned, netting the new hackerspace a 18 kg soldering station.
[Sable Wolf] tipped us off to his DYI desoldering station for under $70. We know we have seen this conversion before, but it hasn’t been featured on Hack a Day. [Sable Wolf’s] hack is unique and has added features that make building, cleaning and the overall longevity sounder. However, some kind of sound deadening housing would have to be built around the pump as it seemed uncomfortably loud in the video.
Some Chinese made desoldering stations are getting quite cheap so maybe it’s not worth the effort unless you can salvage more components for the build. Thanks to [Sable Wolf’s] detailed blog you can browse through his BOM and scrounge up the majority of these items from your salvage bins. A cheap but reliable desoldering station would be an extremely handy tool to have on your bench.
Hot on the heels of our post about reading passwords from EEPROM, [n0th1n6] tipped us off about a similar hack used to resurrect an Eee PC from a bad bios flash. After discovering that a factory repair for a dead bios costs about $200, [CutenaCute_7] took on the challenge herself. She disassembled the computer and desoldered the bios chip from the board. After writing a program to flash the chip using C#, she temporarily soldered jumpers to make sure the flash worked. Looks like this is a zero cost hack, plus the time savings from not having to ship her computer somewhere. Bravo.
Our reader [Damir] built a home made soldering pot. It can be used to solder and desolder components. To remove a through hole component, the solder side is placed in the bath. Then the component is removed with pliers. It is also possible to solder components, by placing the leads in the molten solder; similar to wave soldering. Another common use is tinning self stripping wire. The insulation of the wire is designed to burn off, allowing the strip and tin phase to be single step. This solder pot would be a nice addition to the hacker’s soldering station we had covered in 2008. For more pictures, check out the photo gallery. In the video embedded below, a transformer is easily removed from a modem.