# How to make a Heat Gun ?

#### q12x

Joined Sep 25, 2015
1,137
Hello.
I want to make a Heat gun. A very "quick and dirty" one.
I know there are heat guns to buy, but Im a cheap ass and I want to make one from stuff I have already.
I believe I can make it with what I have.
But I need your advice and your math, since I'm an artist and not an electronist at my base. I know some stuff but to a limit and im not afraid to admit it. So, if you think this is a project you can help me with, then you my friend are awesome !
Ok, so the practical reason is this:

I put two numbers on the image. They represent groups of boards.
|1| group = I recently find 2 full PC's on the dumpster. Near it, but they had some mud inside them already and some iron was starting to rust over 1 night in the rain. I clean them both of mud and dust, I actually put them inside a basin with water and wash them good. Also 2 LCD monitors as well and a old color CRT TV. The TV is not disassembled yet. But the PC's and the monitors are there in that num1 pile.
Some legs of some components I see some rust on them as well. I will sort them later - which is which.
|2| group = is actually a box of cardboard and in it some electronic boards from more than 20 years old. I never had the time to dissasemble them. But with this new pile of electronics I get, I think is the time for #2 to go the disassembling path.
In other words I have a ton of stuff to take out.
The only desoldering means I have are the 2 guys there in the picture
- the blue soldering iron and the red soldering pistol which I rarely use now. It will take me forever with them to desolder anything.
Now, the desoldering Heat Gun components that I have :
I know I need Nichrome wire and I have some stock with it specially planned for years for this heat gun tool to make, but I never had the courage to start it. I find my courage in this period, since im thinking for a couple of days already about it. Planning and scheming.
The diameters are in metric - in milimeters in the picture.
I converted those milimeters to inch for you:
1mm = 0.0393701 inch
0.30mm = 0.011811 inch
0.16mm = 0.006299213 inch
- I know I will need a fan as well. I have a bunch of 12V fans. (and probably 5V ill have to check)
Also from the new dumpster scrap, the 2 PC's, another 3 fans.

My question to you is how to test the nichrome wire. To make it heat to at least 250 degree Celsius, that is the soldering melting point.
This is the part I am not good at. If I can resolve this part then I am 50% done. Ideally is to get a higher temperature, like those commercial heat guns - 550 or 600 degree Celsius. Or even higher !
For my american friends here, fahrenheit is double of celsius. So 600gr C = 1200gr F basically. Not exactly, but very close to this value.
Thank you for reading and I hope we can make it ! I trust in you very deeply !

PS: I forget to mention what Power Sources I can use:
My variable power supply:
which I am afraid not to blow it up.
Since this is a bit unknown thing for me.
And a bag of transformers which I dont care about them too much. They can explode as they wish. They are all working fine.
I wish I can use them more, rather than my VPSU (variable power supply unit).

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#### strantor

Joined Oct 3, 2010
6,040
For my own sketchy mains-voltage nichrome experiments in the past I've used small engine spark plugs to bridge the gap between copper and nichrome and isolate everything from the metal case since solder can't be used.

Figuring out how much you need is pretty straightforward. Get it's ohms per meter either from the spec sheet or by measuring, find out how many meters you need in order to keep the amps under the value that will trip your breaker. From there, the amount of heat it outputs can be found empirically. it will depend on your fan, the shape of nozzle, and other factors.

This is dangerous stuff, file a will. I hope you aren't doing this in someone else's basement.

#### q12x

Joined Sep 25, 2015
1,137
thank you mister @strantor !
Find out how many meters you need in order to keep the amps under the value that will trip your breaker.
That is probably the most helpful idea ever. I never thought in this way, to be sincere.
Also, on the safe side, Im doing it in my sleeping and working room. Everything is under my constant supervision. No worries. Though the idea to make it under someone else roof is not bad. Not to torch my own roof. Hahahaha. Sorry , but i had to joke a bit. But yes, I get your point, I am very careful especially with red hot stuff, and especially in my sleeping room. And im aware of the fumes as well, but eh... maybe I will move in the kitchen or bathroom if the stuff is fumigating too much. Depends on the amount of heat as well I think. We'll see.
Thank you very much!

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#### Ya’akov

Joined Jan 27, 2019
6,276
I feel compelled to point out that you are trying to build something that uses electricity in a way that is very likely to cause fires and electric shocks. It's really not simple to build something safe. If the fan fails, there's fire, if the insulation fails, there's shock. I know how to do this and I wouldn't. Making something that is both safe and useful is more challenge than a cheap commercial version that will be both.

I wouldn't do this for myself and I really think you should consider the potential adverse outcomes.

Good luck.

#### BobTPH

Joined Jun 5, 2013
5,493
If I were doing this, I would start with a hair dryer. Maybe picked up at a garage sale.

Bob

#### BobaMosfet

Joined Jul 1, 2009
2,008
Hello.
I want to make a Heat gun. A very "quick and dirty" one.
I know there are heat guns to buy, but Im a cheap ass and I want to make one from stuff I have already.
I believe I can make it with what I have.
But I need your advice and your math, since I'm an artist and not an electronist at my base. I know some stuff but to a limit and im not afraid to admit it. So, if you think this is a project you can help me with, then you my friend are awesome !
Ok, so the practical reason is this:
View attachment 237450
I put two numbers on the image. They represent groups of boards.
|1| group = I recently find 2 full PC's on the dumpster. Near it, but they had some mud inside them already and some iron was starting to rust over 1 night in the rain. I clean them both of mud and dust, I actually put them inside a basin with water and wash them good. Also 2 LCD monitors as well and a old color CRT TV. The TV is not disassembled yet. But the PC's and the monitors are there in that num1 pile.
Some legs of some components I see some rust on them as well. I will sort them later - which is which.
|2| group = is actually a box of cardboard and in it some electronic boards from more than 20 years old. I never had the time to dissasemble them. But with this new pile of electronics I get, I think is the time for #2 to go the disassembling path.
In other words I have a ton of stuff to take out.
The only desoldering means I have are the 2 guys there in the picture View attachment 237451
- the blue soldering iron and the red soldering pistol which I rarely use now. It will take me forever with them to desolder anything.
Now, the desoldering Heat Gun components that I have :
I know I need Nichrome wire and I have some stock with it specially planned for years for this heat gun tool to make, but I never had the courage to start it. I find my courage in this period, since im thinking for a couple of days already about it. Planning and scheming.
View attachment 237453 The diameters are in metric - in milimeters in the picture.
I converted those milimeters to inch for you:
1mm = 0.0393701 inch
0.30mm = 0.011811 inch
0.16mm = 0.006299213 inch
- I know I will need a fan as well. I have a bunch of 12V fans. (and probably 5V ill have to check)
Also from the new dumpster scrap, the 2 PC's, another 3 fans.
View attachment 237455
My question to you is how to test the nichrome wire. To make it heat to at least 250 degree Celsius, that is the soldering melting point.
This is the part I am not good at. If I can resolve this part then I am 50% done. Ideally is to get a higher temperature, like those commercial heat guns - 550 or 600 degree Celsius. Or even higher !
For my american friends here, fahrenheit is double of celsius. So 600gr C = 1200gr F basically. Not exactly, but very close to this value.
Thank you for reading and I hope we can make it ! I trust in you very deeply !

PS: I forget to mention what Power Sources I can use:
My variable power supply:
View attachment 237461 which I am afraid not to blow it up.
Since this is a bit unknown thing for me.
And a bag of transformers which I dont care about them too much. They can explode as they wish. They are all working fine.
I wish I can use them more, rather than my VPSU (variable power supply unit).
View attachment 237462
@q12x First, slow down. Think. SAFETY FIRST. Nichrome wire is a resistance wire. You an burn yourself or burn your house down if you aren't handling it properly BEFORE you send power through it. You cause it to melt or fry and you don't have something safe for it to fall on, and something to deal with an lingering gases (don't want a fire alarm going off), you could be in a world of hurt in a matter of minutes.

As I work with Nichrome doing such things, and other wires, I had the pleasure of going through all the physics and math associated with conductors in order to verify NEC standards, and where they got their arbitrary limits from (published and non-published)*.

Code:
mm       AWG    NEC_Amps       MAX(Slag)_Amps
------------------------------------------
0.3      28     0.228          8.7
0.16     34     0.056          4.3
1.0      38     0.022          2.7
This is for 1ft of conductor at the given AWG for Nichrome 60 (might be 80). WARNING: MAX(Slag) values are approximate (calculated). Wire derates as it heats, so be aware. Here are some long-haired resources:

https://mycableengineering.com/knowledge-base/calculation-of-k-factor

*You alone are liable and responsible for the use/misuse of this information- I provide it merely for pure informational purposes.

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#### AlbertHall

Joined Jun 4, 2014
12,120
If you want to melt solder with the hot air then you need the air temperature to above 220C and to do that the wire will have to be at a higher temperature than that.

#### q12x

Joined Sep 25, 2015
1,137
This is an update for the Blower Fan case that i'm working on.
If you have any idea how to contain securely, not to tremble, that heating element, now is a very good time to be genius about it. Seriously, I need ideas for securing that heating element. Not be fragile inside it.
I have multiple small videos inside this large video where I show diferent aspects of the project progress.

#### shortbus

Joined Sep 30, 2009
9,532
I don't think you are understanding the difference between a fan and a blower. Your muffin FAN is made to move air through a computer or other device, it is not made to make pressure, but to remove air slowly and very quietly. It creates a negative pressure in what ever it is attached to. A fan usually takes it's air in and out of the blades across the whole of the blade using the air foil principle.

A BLOWER is usually some sort of a squirrel cage or turbine instead of a fan blade. They are made to pressurize a device and create pressure. A blower usually takes in it's air in the center of the blades a moves it out of the edges of the blades to a scroll shaped housing.

A common blower is a hair dryer, compare it to your fan.

https://mechaengineerings.wordpress.com/2015/06/01/difference-between-fan-and-blower/

#### q12x

Joined Sep 25, 2015
1,137
I don't think you are understanding the difference between a fan and a blower.
Oh, I do understand the difference. But what im saying there is that im converting that Fan, into a blower. Im refering to the quantity of air it shout out through the end nozzle. Thats all im trying to make. And so far , it is a blower, more or less. I still have to patch some holes here and there, but by all means, now is something else than a simple fan, because of that special custom case I made. You get me now?
But you probably spotted some typing mistakes I made (for exagerated clarity perhaps in my mind), where I named a "Fan Blower". Haha, yes, that part is wrong, I can see that now.

#### shortbus

Joined Sep 30, 2009
9,532
Oh, I do understand the difference.
You will never get a true blower from that fan, they are two different things. You may get some air but not very much, any restriction on the output of a fan stalls the air flow through it. Sorry but that's just how things work. But then it's your project Just tried to help.

#### q12x

Joined Sep 25, 2015
1,137
You will never get a true blower from that fan, they are two different things. You may get some air but not very much, any restriction on the output of a fan stalls the air flow through it. Sorry but that's just how things work. But then it's your project Just tried to help.
I am aware I will not be able to make a TRUE blower. Not even close. But it will blow some air, through that nozzle suffice to my needs. And If this thing will not work as I want it, then I will find another way, possibly with a real blower, that I actually have and I am trying to make it work:
If this will not work as well, then I will have to find or make a real blower like you are suggesting.
But until that stage, I am happy to get some air flowing, for start.
If you have any suggestion (preferably a cheap one) please put it here.

#### q12x

Joined Sep 25, 2015
1,137
Another update here:

#### q12x

Joined Sep 25, 2015
1,137
The other movie with the circuit idea for this thing:

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#### q12x

Joined Sep 25, 2015
1,137
New failure but Im pushing it to success !

#### q12x

Joined Sep 25, 2015
1,137
And in the end, I cheated.
I buy a new heat gun and that is all. Hahahaha. But really, the experience with the thing I wanted to build, and never could make it... oh boy.
This is a very long video of 1 hour. But it has some funny moments in it.

#### q12x

Joined Sep 25, 2015
1,137
PC Motherboard components scrap - original time length (1h25m)

#### shortbus

Joined Sep 30, 2009
9,532
I buy a new heat gun and that is all.
What kind of "fan" as you call it does it have?

#### q12x

Joined Sep 25, 2015
1,137
Very good question, mister @shortbus !
I didn't open the heat gun, I had absolutely no reason to open it. But you kind of making me curious with your question now. I will open it up and make some pictures or a movie, with its internal motor and probably its circuit(s).