Charper's Hot Air Soldering Iron
An easy DIY project on a college student budget
This project stemmed from the desire to remove (and perhaps one day re-solder) surface mount components. In it's entireity (pictures and all), it took less that two hours and $20. Even if you have to buy everything, I believe the cost could easily be kept under $30. Comparatively, I could not find a hot air soldering iron retain for under $200. Every entrepreneuring young electrical engineer needs to work on some project to satisfy curiosities and take things apart... right? Well, at least I do!
Step 1: Purchased Items
I can't remember where this soldering iron came from, and I've been asked questions about it - if somebody could send me a link or tell me a location where a similar iron could be purchased, I would greatly appreciate it.
Update 2: A reader, Daltore, suggests the "Hakko 503" soldering iron. His full suggestion and reasoning is in the comments below.
Also, there has been a lot of comment on the heat exchanger. Instead of the stainless steel, you could try stripped copper wire, solder wick, or purchase actual copper mesh somewhere.
Aquarium air tubing: $1.13
Aquarium air pump: $6.97
"Chore Boy" Stainless Steel scrubber: $1.37
"Zebra F-301" pens: $4.73
Other items needed:
Soldering Iron, 40 watts or higher
Silicone Fuel Tubing
Dremel (or similar drilling/grinding tool)
The silicone tubing is used as a fuel line in model airplanes, it's reasonably cheap and I'm sure you could find it easily at a local hobby shop or from Froogle, Amazon, or Ebay. Fortunately for me, Aerospace Engineering is big here at MSU, so it wasn't hard to find a friend that didn't mind giving me some. Feel free to come up with a substitute for this if you can - but this stuff seems to hold up extremely well to the heat of the soldering iron.
Step 2: Take Soldering Iron Apart
Luckily, the entire thing is hollow! Every single part of it - including the heating element. It's almost as if this thing were made to be modified.
Step 3: Add heat exchanger
Note: Stainless Steel can catch fire... Use copper if at all possible
Step 4: Pipe air into the heating element with silicone tubing
Step 5: Put the aquarium tubing in the handle of the soldering iron
This shows the tubing through the hole I created in the soldering iron. The placement of this hole actually seems superior to running the line straight out the back of the iron. The air flow can be crudely regulated with a little bit of pressure, pinching the air hose against the handle.
Step 6: Splice the two hoses together and re-assemble
After putting the soldering iron back together - this is what we are left with. What woud be a fully-functioning hot air soldering iron, missing only one small piece: the nozzle. Another pen tip is unscrewed and cut using the dremel cutting accessory shown in this picture.
Step 7: Make a tip
Step 8: Final assembly
Step 9: Final Results
So, how well does a hot air soldering iron really work?
Light on both time and money, I found this project a worthwhile investment, especially for a college student on a budget. Not only can it remove surface mount components, but I found it works really well as a general use soldering iron because of its less-intense heat. For example, a transistor can be soldered in only a few seconds, without the need for the usual soldering heatsinks. For anything but heavy wires, this is a vast improvement over the soldering iron I started out with. In fact, if it weren't for the heating time typical of soldering irons, I would greatly prefer this for general use even to my Cold-Heat device.