Tutorial - How to build your own silent air compressor -( Video Update )

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**KostasIII**

Hello everyone.
Today I’ll open a big tutorial.
How to build your own silent air compressor.
I have to say that I had no idea about compressors. That means it’s easy for everybody.

This time I updatd this post with a video tutorial that I made. I hope to help you

To build the compressor is not difficult but you’ll need some help from a local store that sells air valves and compressor parts.
The important thing is the main idea on how to build it.
Let’s begin!

1) Air compressor

This is the first and the basic thing that you’ll need.
You’ll need a freezer compressor from an old fridge or buy a used one. Why fridge? Because it’s almost free.
Depend on the size of the fridge the motor will have 1/8 Hp (93 Watt), 1/6 Hp (120 Watt), 1/4 Hp (180 Watt) and so on. A label usually on the side says the power. We’ll need 120w or more.
CAUTION: The fridge motor has to be degassed. It is extremely important to properly evacuate all refrigerant from your refrigerator's system. Many shops will do this for free (and add it to their inventory.) This is also a good time to make sure the compressor is working. If not an expert from a local store will help you

Once all the gas is out of the system, cut the copper tubes. There's one going in & one going out of the sealed compressor module. Use a tubing cutter for the job. Note that when cutting, leave as much length of copper tubing as possible with compressor. Try not to turn the unit upside down.
The compressor will have 3 copper tubes.
a) The one that is sealed if for the refrigerant – leave it as it is
b) The one with the smaller intersection (size) is for the suction (the air comes in).
c) The other one is for the supply of compressed air (the air comes out).

If the compressor if old put some very thin oil from any tube (mostly 200ml is full)

NOTE: every time you’ll use the compressor a very small amount of oil will come out from the tube that supply the air. So after a big amount of time you will need to add some oil again. (Don’t worry about the oil comes out. Is good to have oil! I’ll show you later why)

The power wires are two. One for power and the other goes to the thermostat. Cut the wires that go to thermostat.
Remove the wiring to everything else except the capacitor and pump. Connect corresponding power cord wires to the capacitor and green ground wire to base of pump.
Test if the compressor works ok.

This video will help (it’s not mine)

Put a filter on the tube that the air comes in (mostly for protection like a window screen)

Now that it is all ok we are ready to go on.

2) Air tank

Here is a variety of choices
a) A cheap and loud as a jet engine compressor from a hardware store and just change the compressor unit
b) Fire extinguisher CO2 (only)
c) Portable air tank
d) Pure oxygen or nitrogen tank
e) Any other tank that can hold at least 10bar pressure.
I have an air tank from a truck! (from airbrake system)

CAUTION: Do not use gas tank. It is not safe to use it.
NOTE: All air tanks must have at least 2 holes – inflow points (sorry but I can’t translate it)

If you choose the first option then the only thing that you’ll need is to remove the jet engine and adjust the fridge compressor on it.
If you choose the other ones then you have to make modifications .

Fire extinguisher CO2
This is the most difficult option you can choose because it doesn’t have 2 holes and you have to make the right thread.

a) Empty the extinguisher
b) Unscrew its lid
c) Wash and clean the inside of the bottle
d) Drill 1 or 2 holes 10mm diameter
CAUTION: Don’t drill holes empty extinguisher if you don’t remove firstly the lid.
e) Glues with electric welding 2 thick nuts ½ of an inch (1/2 inch is indicative, you place the size that the pressure meters of the plugs will be)
(I can’t find the right translation for nuts but I mean this…..)

Usually the small fire extinguishers can hold up to 16-20 bar pressure but because we have drilled holes its pressure resistance has decreased.

Now hold!

Portable air tank
Ready to use

Pure oxygen or nitrogen tank
If it has holes then go on else see fire extinguisher.

3) Other basic parts

a) Relief valve: when the pressure goes over the limit of safety we want it “opens” and releases the extra pressure. It is for safety reasons but if you don’t have it you will definitely BREAK something. Adjust it to 9 - 9,5 bar.
b) Air pressostat: This is the brain or your compressor. Buy the one with the 4 outputs and can connect with a one way valve. The pressostat is being connected between the electric power and the air compressor. Adjust it to open at 5 Bar and close at 8 Bar. This means that when the pressure in the tanks reaches the 8 Bar the pressostat “cuts” the power to the compressor. When the air pressure falls to 5 Bar the pressostat give the power again to the compressor.
Most of the parts connected here.
c) Manometer 10 bar: So you can see the tank pressure
d) One way valve or check valve: This goes between the air compressor and the air tank. For safety reasons the air compressor does not start if it indicates pressure inside it. So the one way valve pressure help the compressor by not letting the air goes back and went the pressostat stops it release the pressure inside the compressor. Without it the compressor will not start until the pressure goes to 0 bars.
e) Pressure regulator: Please buy a good one. This is one of the most important and useful thing you should have. This regulates the pressure you’ll have at the airbrush. The good one has also a manometer (must have) up to 3 bar and an air filter (must have) that traps the moisture and the oil.
f) Drain valve: This is used to drain the water and the oil that the air tank has trapped inside. Don’t freak out about the oil. It will prevent your air tank to rust and there is no way to reach at your airbrush.
g) Spare parts: like on-off small valve and connection parts like lot of teflon tape, rakors, a high pressure tube etc. Ask your local store who sells air compressor parts to help you.
h) Base: This is up to you. Use your imagination … your favorite tools and create one. Prefer adjust your air tank vertical and not horizontal. It is best for the rust.

4) Assembly
a) place the air compressor and the air tank to the base
b) connect the air pressostat with the air tank
c) connect the air pressostat with the power and with the compressor
d) connect the one way valve with the compressor and the air pressostat
e) plug relief valve to the air pressostat
f) plug the 10 bar manometer to the air pressostat
g) connect the pressure regulator to the air pressostat
h) connect the pressure regulator with an on-off valve.
i) connect the air compressor to the air tank with the rakors or the high pressure tube.
j) plug the drain valve to the air tank.
NOTE: use to connection lot of Teflon tape.

This is the one way valve

Connect the air pressostat with the power and with the compressor

And ready to go!!!

5) It’s ALIVE
This is the final stage!!!

a) Check that you have assemble the relief valve (VERY IMPORTANT)
b) close the on-off valve so as not to lose air pressure
c) turn on the air pressostat
d) try to hear air leaks
e) check the pressure if it stops at the 8 bar

If all it’s ok then …………………… YOU’VE MADE IT

Now you can paint at 3.00 in the morning!

Finally I have to say I don’t have any responsibility for mistakes you make … bla, bla, bla You must take all the protections bla, bla, bla …

I hope to help you guys.
Sorry again for my English but I really tried.

see ya
bye

**Jaeger wulf**

Wow, all credit to you, but you can paint at 3am with an air compressor from eBay for about $99...

**SilverMK2**

Very involved but I suppose quite useful if you are skilled and have an older, or larger compressor which is noisy.

However, most modelling compressors are reasonably quiet now. Mine is only 49dB and is about as loud as a quiet conversation - only about £40 too...

However, thank you for posting - I am sure someone will find it useful

**Ulterior**

Great tutorial. I was a refrigeration mechanic for a good while, and this tutorial is wonderful from both a layman and a trades person point of view. Thanks for documenting the process!

**Maxstreel**

This is inspiring... I'll have to give it a shot. Thank you!

**hayabura**

thank you

air compressor

**morfydd**

Extreamly usefull ..cheap rebuild for my older small compressor thats used for airbrushing etc..and keep my wife off my back about wasting money ..when what she wants is a new fridge ..(she gets her new fridge the olde one hits the garage the one in the garage gets taken apart for my air compressor and the balance sold as scrap..

**Ouze**

I strongly suspect the parts for this project, even used, will cost more then simply buying a low-end compressor and yield a less desirable end result for our purposes.

Perhaps if you have access to a local junkyard....

**Adam LongWalker**

Damn I got to respect the man for his ingenuity. Great editorial on the creativity of the project.

**KostasIII**

Hello everyone and thank you very much for your comments.

I have to add some things
1) The relief valve, is also knows as a blow off valve or safety valve
2) Checking for air leaks is easier using soapy water
3) 1 Bar = 14.5 PSI

About the cost I can't say that this compressor is the cheapest compressor but...
- You get a SILENT air compressor not "like silent"
- The air tank can be as big as you want. OK so what?!! Small or none air tanks makes the compressor works all the time. That will soon overheat the air compressor and you will have HOT air to your airbrush!!! With air tank you avoid it.
- It is your creation!

**Spyral**

Pretty funky but I'd be keen not to mess with a refridgeration unit with its freon or whatnot inside.

**KostasIII**

Pretty funky but I'd be keen not to mess with a refridgeration unit with its freon or whatnot inside.

There is no need to afraid. You can just call a refrigerant (or a friend who knows) and take away the freon. (I think they do it for free)

**Dullspork**

I have a small noisy compressor and I have a small fridge in my basement that hasn't been used in years. I see a new project in my future.

**KostasIII**

Hello to all. This is an update for the building tutorial I had already made about a year before.
Thanks a lot

**psnmario**

This is very cool, I might have a project to do

**Bi'ios**

It's not very practical, but a really interesting project. You could buy a compressor for cheaper that this costs to make, but it's cool.

**Dullspork**

Bi'ios wrote:
It's not very practical, but a really interesting project. You could buy a compressor for cheaper that this costs to make, but it's cool.

I doubt you could buy a silent compressor that's cheaper than this.

**Boba Fett**

Cool idea! Might give that a try
Upcycling!thanks for sharing this great idea

**KostasIII**

Bi'ios
Post 18/08/2014 05:37:28 Subject: Tutorial - How to build your own silent air compressor -( Video Update )
It's not very practical, but a really interesting project. You could buy a compressor for cheaper that this costs to make, but it's cool.

Dullspork
Post 23/08/2014 22:22:51 Subject: Tutorial - How to build your own silent air compressor -( Video Update )

Bi'ios wrote:
It's not very practical, but a really interesting project. You could buy a compressor for cheaper that this costs to make, but it's cool.

I doubt you could buy a silent compressor that's cheaper than this.

I totally agree. The cost here in Greece is about 80-100euros or 100-120 dollars.
At this cost you can only buy the cheapest air compressor from amazon or ebay. Also them are not silent and they don't have always steady pressure.

Boba Fett
Post 24/08/2014 01:50:12 Subject: Tutorial - How to build your own silent air compressor -( Video Update )
Cool idea! Might give that a try
Upcycling!thanks for sharing this great idea

Please if you try it let me know or post a photo. Thank you

**dreamcompressors**

Thanks for sharing,i think that just used small air compressor or Non - industrial air compressor.The Larger Industry High Pressure Air Compressor which is noisy.