Hot Air Pencil For Under $20


Here’s a project from back in 2001 that might be of interest to some of you. It is a guide on how to build your own hot air pencil for SMD soldering.  He is using a super cheap 45W soldering iron from “the shack” combined with a pump type desoldering tool and an aquarium pump. He says it works pretty well, and we don’t see why it shouldn’t. This is a pretty elegant solution. There are also some more recent versions of this mod, but the idea is basically the same.

[thanks Stuart]

36 thoughts on “Hot Air Pencil For Under $20

  1. These units work awesome all by themselves. No need to hack them. I have a vintage model (1980s) and it STILL WORKS. They take a bit of time to startup but are absolutely indespensible.

    Not so good for removing surface mount items but the through hole stuff comes off super easy.

    -=/ Daft Tech /=-

  2. Nice solution, but it worthless for anything larger than desoldering SO-8 from the board.
    Hot air station based on that needs a bit more oomph to work, air blowing through a small tube will not heat enough with big air flow, I’d opt for some kind of heat exchanger.
    On desoldering side I think it will do much better, provided the air after the iron is cooled and there will be trap for the solder. Soldering iron for the job should powerful so it wont cool.
    Solder trap could be done with a coffee filter or something like that (Weller & Ersa have similas solutions).

  3. @matt: probrably would. In fact, the ‘more recent version’ suggests as much by noting it’s got a lower wattage than the older one using the RS iron. I also think the RS hack is more elegant as the steel wool both captures heat AND restricts airflow. The ‘more recent’ dude’s implimentation attacked both issues independently.

  4. I actually bought a 12V compressor and a desoldering iron to do this hack a while ago… then I used the desoldering iron for it’s intended purpose and I ended up throwing a plug kit plus the compressor in the back of my truck in place of the spare tire… those cheap RS desoldering irons are actually pretty damn useful.

  5. Older than the internet.
    I tried this about a year ago. It’s a neat idea, but it doesn’t work well enough to be practical. It takes a very long time to warm up (the pump must be off during this period or else it never heats up at all) and when it finally does, its a really clumsy and difficult tool to use.

  6. Also, note that connecting the tube directly to the iron is a bad idea. It’s better to poke a hole in the back of the silicone bulb and insert the tube into that so that it is insulated from the heat.

  7. I have come to comment and I saw all people saying almost the same I come to say.
    There’s no way that works.
    it’s like trying to make some water heather, using one feet of cooper pipe and a Bunsen lighter.

  8. I live in the UK, and cannot find anywhere that sells these type of irons cheaply. That said, there is an instructable on turning a hot-air gun into a hot-air solder station which seem preferable to me. Now, if I can just find a large copper pipe corner…

  9. doesn’t work!
    i tried it as well, with increased air flow, with reduced air flow, smaller tip, better heat exchanger, a modification, where the air gets blown through the iron -still useless
    at least i now know more than i used to:
    if you want to heat up air to the temperature of a soldering iron and don’t have an infinite amount of time, what you need is not a soldering iron, but something that is hotter than a soldering iron- basic physics, duh! every heat exchanger is built that way.
    so what i learned is to trust my own knowledge, even if some bright bulb tells me about his great awesome hack, and forgets to mention the tiny detail, that it doesn’t work.
    my radio-shack version got disassembled, my new version at least works for welding soft-PE ;)

  10. I tried this over the summer. I don’t know if it’s the greatest thing for actual soldering but it is a pretty useful tool. I was able to desolder some SMD resistors and capacitors with it and solder them back on but it took a ridiculously long time to get anything hot enough to melt solder. However, it works really well with heat-shrink tubing, almost the perfect heat. It isn’t so hot as to burn the tubing quickly but it shrinks it very well. It can also be used to melt plastic and wire insulation. I added a ton of steel wool in the tip of the thing, jammed it in until I couldn’t fit any more and it still has good airflow. Steel wool seems to be a good heat exchanging material for this iron.

  11. oh bill, if something is posted as a great hack and five people who built it already think it’s junk, what should they do?
    a) voice their opinion
    b) stay quiet and let others find out for themselves

    i admit, option b) reduces the crybabyness-factor of this site. but info-tainment-amusement over learning? that’s only preferable for theoretical hackers. you know, the kind who read this and think “wow, cool all the stuff that’s out there. some day i might build something like that.”

    1. @tantris,
      Wouldn’t it also be possible for them to state that they’ve done it and explain that it didn’t work out in a positive manner? I know I appreciate knowing the pitfalls before I get started. But yeah, no need to bash the project.

  12. @Caleb
    agreed. the tone isn’t always the nicest here.
    but sometimes rude and irritated is hard to distinguish. and i admit, i got irritated: the original writeup goes through the steps, without mentioning that it kind of doesn’t work that well. Paddy’s blog ( mentioned as “more recent version” above) is much better: go through the steps and report whether that works or not.
    unfortunately, hackaday just linked to it as “more recent version” and forgot to mention, that’ it doesn’t work.
    i wouldn’t bash the project as a whole. (i am looking for curling irons and broken toasters right now..) but there are write ups that are bad and misleading, and good ones that are open to (constructive) criticism.

  13. This toll work great as desoldering tool but as hot air desoldering it just newer work, you will overheat and burn all components before you desolder them with this, trust me I tried to do this many times before buying hot air station

  14. Yep, made one a couple years ago according to the earlier Hackaday post, didn’t work terribly well. Some tricks to make it work:
    – Get a high-watt desolderer.
    – Include a footswitch to control the pump.
    – Severely restrict air flow.
    – That steel wool trick looks reasonable.
    I don’t use it for that purpose anymore; it still desolders, and I got a real SMD rework station for real work; it’s worth it.

  15. Tried it back in 07 and it didn’t work, I didn’t try too hard honestly. A hot air paint stripper or a hot plate works with less effort.

    I would like to see more DIY hot air irons, perhaps with temp control. You can buy a spool of nichrome wire from ebay or from

  16. I also tried this one out, over the summer, but it didnt work all that well. I tried changing it a bit, after the initial not working, by adding a thin brass pipe down the center of the soldering iron, to hold more steel wool, and adding a finer tip taken from a steel mechanical pencil, it still didnt work.

  17. what the fuck is the point of posting stuff like this when it doesnt even work???? hell,even the author of the “more recent version” states that point blank.

    and now,back to your regularly scheduled aurdino commercials.

  18. LOL; from the blog spot link “It didn’t work! At least not on the solder on the circuit board.” I hope you work from home Stuart, in my part of the world you get a large ration of shit when you get to the shop.

  19. When I first saw this hack I thought it was a good idea, and it will work in a pinch, but in the end I decided to buy a real rework station instead because this is just not good enough for anything that you’re trying to take serious.

  20. i was wondering if any knows if the pinout on the 968A+ if it is the same as the 474a+
    and if the pump is the same? i no the specs say that both 231air just wonder if you
    could hook up the replacment gun for 474a+ to 968a+and make your station desolder 2
    i welcome your input thanks

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