DIY Hot Air Soldering Iron

Also Available on my website

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

UPDATE
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.

Items Purchased

Aquarium air tubing: $1.13
Aquarium air pump: $6.97
"Chore Boy" Stainless Steel scrubber: $1.37
"Zebra F-301" pens: $4.73

Total: $14.20

Other items needed:
Super Glue
Soldering Iron, 40 watts or higher
Silicone Fuel Tubing

Tools:
Screwdriver
Scissors
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.

Comments

[carlitoscr]

Well, I think you can use a piece of copper solder wick as your heat exchange element. you can either place the piece of solder wick as it is (being careful it doesn't offer too much resistence to the air flow) or you can take your time to separate all the copper threads and then make a small ball with them (be carefull not to compress that ball, it has to be porous). Use the porous copper thread ball as your heat exchange element. Good luck!

[Ian01]

These wicks usually contain rosin flux, which could be detrimental. On the other hand, you might get vaporized flux that could help with the desoldering.

[conny17017]

How about using some of the woven copper or aluminum jacketing on coax cables

[Polymorph]

The aluminum will corrode quickly in the heat, don't know how much that will affect it. Good idea, though.

[Ian01]

The copper would probably work, but I wouldn't use aluminium because its melting point may be too low. That's why it isn't used for model rocket launch stands. Those have steel blast plates.

[beehard44]

i melted aluminum with the whoosh rocket once

[techno guy]

Can you use steel wool for the heat exchanger?

[Mirage_662]

Thermal lance anyone?

[charper]

I wouldn't. Steel wool can be flammable.

[charlieb000]

just an idea, perhaps it is possible to replace the tip with a tube and use that as an air duct. then you can use the iron as a iron again when you want. i have a 40W thats not really suitable for soldering but if i need it to burn stuff again then i can just put the old tip in.

[ledartist]

Amazing. Only if I knew this before I purchased my hot air tool...
Live and learn. Thanks!

[omnistructable]

Velleman TSS5 50W soldering iron works great. It is almost air tight. Use information in this instructable to make the nossle and heat exchanger. I didn't put a silicone tube inside the heater, I have just drilled a hole in the handle and connect the aquarium hose to it with an aquarium T-piece with the one end blocked.

[Bigfish_102390]

I have a soldering iron I'm curious as to how u get the sheathing loose without hurting the iron because it is riveted to the handle.

[Astinsan]

The epoxy your talking about is QuikTitanium Epoxy PuttyQuikTitanium Epoxy Putty. It can do a Service temperature -40 to 500º F (-40 to 260º C)(hd has it in the paint department) . There are also exhaust pipe patch kits for cars that will work, Then there is the stuff for fireplaces that is in a calk gun container made by 3m (hd has it in the paint department)

[soldering iron]

Recently, I had to replace the heater assembly for the TJ-70 Mini ThermoJet hot-air handpiece - this is part of  my Pace MBT250 soldering station. The cost of the part was $125.00 (without shipping charges). It is also possible to buy the complete ThermoJet hot-air handpiece assembly (TJ-70 for the Pace MBT250-SDPT) for $335.00.  You made  similar hot-air  soldering iron for much less money!

[DiscoElf]

What diameter / gauge is the silicone tubing please

[CalcProgrammer1]

I just built one of these using the RadioShack 45W desoldering iron. It's a lot easier to make, just pull off the bulb and slip on the air tube and stuff some steel wool into the chamber where the tip goes. I had to put a lot of steel wool in but I finally got it hot enough to remove and solder SMD components. Total cost was $11 considering I already had an old air pump and air hose, just had to buy the desoldering iron.

[charper]

That, sir, is an excellent use of pre-existing products. As a bonus, I'd imagine it's easy to remove the air hose and continue using it as a suction device.

[dphc]

I tried the RadioShack 45W desoldering iron (part # 64-2060), but couldn't achieve satisfactory results. I stuffed the tip with various amounts of copper speaker wire (chemically cleaned first) and connected the pump to a speed controller to slow it down, couldn't get it hot enough to melt solder that's already on a board.

I was sort of pissed after messing with it for 2 days, but then realized I might be better off giving this instructable a shot with the Hakko 503. I'm expecting better results since the Hakko is 60W and has fewer metal parts (which lose heat by transferring it to the surrounding air before it gets to the tip) when compared to the RadioShack iron. The only drawback I can see with the Hakko (so far - haven't picked one up yet) are those little vent holes in the sheathing, but I'm going to seal them with some JB Weld. That way I shouldn't have to run the silicone tube all the way up to the heating element.

Anyhow, thanks for posting this instructable; I'm hoping it will work out better for me :)

[Madcat Mayhem]

I too have tried the 45 desoldering iron from radioshack. Very disappointing because copper wire, steel or copper wool, nothing in the cavity works. I think the air pump from the pet store isnt good enough. I notice there isnt a certain kind of air pump mentioned just prices below $10.

Radioshack's desolder iron also has a bore. Im gonna try getting an air line through the handle similar to this one.

[cdousley]

could i veverse the polarity on the motor to make it suck air?

[beehard44]

why do you want it to suck air?

[cdousley]

to suck up the solder like a desoldering iron but now that i think about it it probably wont work

[PetervG]

I got a ColdHeat yesterday! XD

[Shark500]

i pray for your soul. the cold heat soldering iron is probably the worst soldering tool ever created. tips break too easy and are far to expencive. the entire concept of how the cold heat soldering iron works is completly retarded. go to radio shack and get yourself a butane soldering iron.

[YummyPancakes]

Yeah. I remember my first soldering iron was a ColdHeat... *shivers* Won't use THAT one ever again.

[disturbedreaper]

i have the cold heat my god its a complete mockery. it makes a complete disaster you cant solder anything smaller than an inch in diameter.

[beehard44]

cold and heat. Mix 'em together you've got a crappy product

[PetervG]

Yea, its hard to get it to work, i'm a beginner so I like having a wireless one and you dont have to wait. Anyways, good for fast jobs, sorta. I have to get the hang of it.

[static]

Personally I wouldn't recommend the Cold Heat tool to a beginner, because the way you you have to futz with it to get it just so to heat the connection. I have to consider the Cold Heat a tool for those who have already mastered soldering and, instinctively know when the job should be good. 30 years ago I had a Wahl rechargeable http://www.starkelectronic.com/wahl.htm and just loved it. Anyway if you already have it, no need to toss it in favor of another style of cordless iron.

[PetervG]

Yeah, that comment is old. The tip broke.

[charper]

Oh come on... if you use it for what it's really good for, it's great. Quick, short jobs where a low-power resistance soldering iron really shines. You're right about the tips, but I found that a nail file (black emory board?) works realllly well for re-sharpening and cleaning the melted plastic out of it. I've had moderate use out of my cold heat for about 2 years now and have never replaced the tip.

[Sync]

omg yes. cold heat ISNT that bad. ive been using mine for a while and nothings broken...

[Crash2108]

If you use it you know what it's good for. Nothing. The stripper it comes with is worth more.

[Shark500]

my stripper broke after 3 uses :/

[Crash2108]

You should put more money in her panties.

[_soapy_]

lol. I didn't even get a stripper with my ColdHeat, which was the worst £20 I ever spent. It takes longer to get the darned thing to solder than it does to get my great butane one, and fire that up, unless it is a *single* joint. It doesn't even heat the solder hot enough half the time, even with Duracells. I'd say it was just Cold.

[toogers]

lol, coldwarm tool. it solders 2 % of the time!

[lilshawn]

i had the cold heat, problem is... it's a resistive type of heat generator... if you slip (which i have done with it before) and bridge 2 connections, your dumping your electricity into the device.


Iv'e blown a couple of transistors and leds with the cold heat. I'm a regular iron user now.

[MaXoR]

lol, I always thought that could happen! I've never really used it, since mine couldn't even get solder to solidify on it's own, let alone attached to a metal post. I've always wanted to make it into a "wired" iron by giving it a battery pack, so it can have top amperage for the longest time. However since you mention this LARGE draw back (Because lets face it, what other application does the cold heat soldering iron have than to be used on small electronic parts), it's a failed product that sadly can still be purchased today.

If you are just soldering two wires together, then maybe this will be a practical tool for you, however those that need to do computer repair work, just go get a 90W and be done with it. A 90W heats up quickly, allows for almost instantaneous melting of the solder joint, so less time to transfer that heat to the parts.

As well, I want to make a side remark about de-soldering wick, it's made by "Goot" and a few other companies. It takes forEVER to heat up, you have to KEEP it hot enough to melt solder, and if you don't have a monster iron, you will likely just fuss with that sort of thing. I've long since learned a good cheap solder sucker is all you really need.