INSANELY HOT DIY Hot Air Soldering Iron @ 15 Volts DC and 3.5 Amps...PART II




About: Geologist buff with a flair for photography and mad creations

359 degrees centigrade and with room for more ;) This is the permanent version to my earlier prototype. I have added adjustable nozzles, used a smaller heater element and of all things, butchered a scooter handle to hold it all together. If you look at this and my other instructable, you are surely able to make your own. Big improvement with this final model is that the heating element is thermally isolated from the main housing...a big change from the standard shop brought soldering irons. This isolation of heat allowed me to reach insane temperatures without cooking my hand. Here is the link click here to the prototype that started this off....

anyways...i have stated my experiences and since making the front page of MAKE, some people have their noses out of joint and have become quiet the TROLL...this is it for me and I merely posted my experience and did not baffle anyone with theoretical tripe...You make your own mind up....I am not into defending myself against TROLLS who think they know better than anyone else...You all have good weekend, and if I create another working project, remind me to proclaim that the world is not flat and give my accusers a bundle of stones

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Step 1: To Start, You Need One of These...

Hot air gun from the dump...or anywhere you can get your hands on one. Does not need to work. The down side is that you need to get one that has cylindrical ceramic tubing in the heater department - see later stuff for more of what I mean. The metal tube housing and all attached bitz such as motor is what you will need if you follow this instructable.

Step 2: The Fan Is Important

This style of fan compresses and forces the air out of the blower unit into and through a smaller opening such as the nozzle end of my DIY soldering iron. I had earlier made a fan that I thought would be good, but it dd not emit much air out of the narrow opening...I am thinking an air pump from an aquarium that has several internal diaphragms may be of use here...A simple 12 volt car air compressor would be great too, but they are too noisy, but worth a look at later.

Step 3: Choosing a Motor to Pump Your Air.

I had several motors I looked at and in the end, decided on using the assembly I had created from earlier instructable prototype, using the original motor and fan assembly from the heat gun I butchered. Of interest to me is the induction motors I have...brushless and will go on forever..and much quieter than the standard my own time I will figure out how these are wired, as I haven't a clue.

Step 4: Scooter Handle Was Just Ideal to Hold Everything.

I wanted a larger housing to hold the element in place with the idea of isolating the heating element from the metal main casing. It was not to be too large and not too small. I butchered this scooter handle from my parts shed and began to start work.

Step 5: Find the Ideal Length of Heating Element

This picture shows a way too long heating element to run from 12 volts DC. Using a small 12 volt battery, I downsized the heating element until it started to glow red...this was to be my starting point and choice of length. This heating element was taken from the heat gun I butchered...I had some other elements, but in bending the wires, they good, so I threw those ones out. This element had good ductile deformation properties...must have been a new hot air gun before it croaked it.

Step 6: Reshape Your Heating Element

Once you have the desired length of element, it may need some reshaping to remove any kinks etc, I used this dremmel bit to hold the element while I reshaped it.

Step 7: Ultimate Insulator...

This mica roll I removed from the inside barrel of the hot air gun...just perfect, to roll up into a smaller size and insert into my scooter careful in rolling it as this stuff is brittle. This would help shield the main metal barrel from the radiating heat emitted from ceramic tube shown later.

Step 8: Make Your Own Insulation Washers.

Needed to make heaps of washers as I did not have any insulated solid tubing to get the result I wanted. Fiberglass sheets were careful with this stuff as when you grind it with a dremmel, you are actually creating microscopic glass shards/powder. Wear a mask and gloves as this stuff makes you itch. These washers will help isolate the heating element from the main barrel. Here, I used a five cent piece as a template. The coin actually just fit inside the barrel of the scooter handle, so is the ideal size.

Step 9: After an Hour, I Made Heaps of These...

What you can create with a dremmel...what I did not have, I just took longer to get the job done!

Step 10: Tricky to Seperate the Heating Element From the Main Barrel.

Making two washers with the same outside diameter but different inside diameters, I was able to use some non conductive metal cement and glue the two washers together. Then Repeated the same procedure for the other end. This will actually separate the heating element from the main body. To see if my idea worked, I place a lighter on one end of a washer and held the other side of the washer with my hand while a lighter flame heated the washer up...heat did not travel (conduct) to my fingers. Ideal stuff!!!

Step 11: The Heating Element Complete

This is the idea I wanted to get. Do this and you are off to a great start. My earlier prototype had the ceramic tube flush against the main barrel. While still cooler than a standard soldering iron, I wanted better efficiency and more heat out of the nozzle end, so I created the washers to help reduce heat conduction.

Step 12: Cose Up View of Output End

As the washers are going to be stacked and glued to create the tubing I wanted, I had to make sure the heating element wire was recessed into the washer . This just makes less obstructions, turbulence inside the barrel from the passing through air and also help to isolate the hot air from comming into contact with the main outer housing scooter handle.

Step 13: More Electrical Isolation and Heat Protection.

Close up view of the element and some sheathing I added to the wire running up outside the ceramic barrel. You can see some of the interchangeable nozzles here that I use later to control air dispersion at the output end.

Step 14: More Washers

These washers were made to allow room for the wire to exit the heating element to the power supply connector bit. As the washers are going to sit flush together and stacked to form tubes of different lengths, this is essential step.

Step 15: How to Connect Element to Power Supply.

I recycled some connections from the heat gun and used those to create the essential connection between the element and power wires. I later discarded this rivet idea, as I wanted something later that would allow easy removal and replacement of a stuffed element. I opted to use super thin bolts and nuts and small spring washers to join the two ends together. There is nothing preventing this idea of the rivets holding the wires together if you can not find nuts and bolts small enough to do the job. Remember that they must be small enough to clear the outer metal don't want an electrical contact

Step 16: Close Up of the Rivet Joining

This is a close up of the rivet idea...As i said, i ended up using thin bolts and nuts attchacing the wires here.

Step 17: The Nozzle End

One end of the scooter handle I created a flange to mechanically seat the nozzle. I first dremelled the edge to a 45 degree angle and the bashed the end with a hammer, turning the tube with each hit to create the inverted flange that will prevent the nozzle from falling out here...I worried about the other end

Step 18: The Nozzle

This is the important end. You can see the thermal isolation created by the washers I made. The main nozzle is a brass tube from a weed sprayer. I cleaned it up of course before using it here. This weed sprayer was from the local dump and I ended up getting some extra nozzles that will come handy.

Step 19: Heat Sheild

This mica sheeted roll was ideal for isolating the ceramic barrel housing the element from the scooter handle and the effects of radiant heat. Without it, I noted the heat of the barrel was similar to that of a typical soldering iron...not the effect I wanted...So I added this shield, butchered from the heat gun

Step 20: Fitting the Power Connection

This is the rivet idea still and how it all fits into place...the idea I used was much cleaner than this, where I discarded the rivet method and used nuts and bolts instead.

Step 21: How It Was All Going to Be Joined Together...

This is the idea I came up with to house the unit together. The washer to the far right was going to be held in place by three metal screws drilled into the scooter handle...I liked using the thin bolts idea as it discarded the need for all of this seen here.

Step 22: How It Would Have Looked

Using rivets instead of nuts and bolts...this is the effect you should aim for!

Step 23: Electrical Insulation

This is how i solved the housing problem inside the unit...the spring pushes everything up nicely against the nozzle. The flexible insulation tubing seen here adds further protection of the power leads from the main spring. The perfect wire I found was butchered from an old metal halogen light fitting. It was thick and insulated and heat resistant. I held a lighter to the wire I salvaged and it did not burn, melt or smoke...excellent. It even had the ring connection on one end that is exactly the same size as the ones shown previously at the ends of the white and blue wires. Because the wire is so thick, it actually was used to push everything flush against the nozzle, kewlies

Step 24: I Got Just Over 360 Degrees Celcuis, But Missed the Capture...damned Slow Camera

Wickedly hot air ...and concentrated ....and controlled.... everything I had ever wanted during this past week of making this beast. Changing nozzles changes the width of the heated air being forced out...changing the voltage in conjunction with the air flow changes the temperature. That is, increasing the airflow allows me to reach even more insane hotness by increasing the voltage. The element was glowing red at this point and I still could place my fingers onto the barrel without hurting them...If I laid my fingers there for too long it got a bit hot though.

Step 25: Power Consumtion

Basically nearly at full steam....15 volts DC and 3.4 amps. Use a voltage regulator if you can or tinker with an old computer power supply abd adjust the length of your heating element to your desired voltage input

Step 26: The Old Blower Unit From My Instructable Prototype.

It was a bummer that I could not use the motor I wanted to as the fan was not compressing the air enough into a smaller I used the blower assembly I butchered from the heat gun and created this masterpiece.

Step 27: This Is It !!!

The final unit with power and air nozzles exiting from the handle...thank you old scooter, you served me well ;)

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    81 Discussions

    GO chispa GO

    3 years ago

    Today in 2016, there are options more easy & cheap:ón-De-Soldadura-Por-Aire-Caliente-15/

    to all those people commenting about the current availability and low price for a tool of this kind, beware, as is it not the same in other countries, you all are blessed to be in a first world country, for those of us living in the outside,aka third world, this is an excellent post for something with such a prohibitive price. thanks for posting this instructable.


    8 years ago on Introduction

    I guess this would be ok if you have a heat gun with a ceramic encapsulated element that has a broken handle or something, but before you spend any time or effort, realize that you can buy a hot air rework station for about a hundred dollars new. It will have all kinds of safety features that this does not, and temp and air flow controls, digital displays etc. Actually my ten year old Steinel heat gun will do things that this cannot and you can pick up a nice used one for 30 on ebay or even less if you are patient. This is not even close to insanely hot. My old Steinel still goes to 820 C which is fairly standard and not at all insane, and has infinitely adjustable heat and air (within parameters) I got it for about $50 ten years ago. By the way, some of the people you are in some kind of flame thing with are right, you should take the word of professionals with twenty years experience who are trying to clue you. Here is a link to a video of a professional hot air rework station being built. It has both an iron and hot air.

    1 reply

    Reply 5 years ago on Introduction

    Thanks for the link. Very high efficient production. I can see the whole hot air rework station to be assembled within 9 minutes. To find out more about this topic, you can check out the hot air rework station reviews here. BTW, a professional hot air station costs around $50. For safety concern, most of us should consider buying one other than making it by yourself.


    9 years ago on Step 10

    where i can find a ceramic tube like that???


    Reply 10 years ago on Introduction

    400 degrees Fahrenheit is enough to melt solder 359 degrees Celsius is 678 degrees Fahrenheit that's about 200 degrees over solder's melting temperature


    10 years ago on Introduction

    Just thought I would leave a comment here.. Ozzy, your instructable is a good one, and you've done a wonderful job in making this hot air soldering/de-soldering gun. It is an ingenious project.

    However, those whom you are calling Trolls (and who are doing nothing in the realm of trolling) are actually correct. These devices have been around for ages... you have not invented anything new here. I know you don't necessarily claim to have done so...however I have to point out that some of us have had a lot of experience using devices like this, and you are jumping to some wrong conclusions.

    This doesn't mean you did a bad job in making your device, or that it is worthless, etc.; it only means that this device has some specific uses in which it excels, and normal everyday soldering is no one of them. Yes it can do that job, but not as good as the traditional metal tipped soldering irons.

    A google search can easily reveal the commercially available devices like this, and some online research will equally readily reveal the fact that they are not the best thing for traditional soldering.

    That doesn't mean it cannot be used for such, only that it is not as good as a normal soldering iron.

    1 reply

    Reply 9 years ago on Introduction

     It used to solder SMD components and BGA chips and not intended for hole through technology.


    12 years ago on Introduction

    That's comprehensive. How does hot air compare to hot metal, with regard to frying components on the board? I guess you'd be mainly using the underside? L

    2 replies

    Reply 12 years ago on Introduction

    Transfer of heat to desired object is obviously much quicker with air from what I have experienced using this tool.


    Reply 12 years ago on Introduction

    What about heat transfer to other objects? Again, I guess you're using this on the underside?