DIY Silent Air Compressor

This article is posted on behalf of Adam and details how he built his silent aircompressor.

After getting tired of not being able to airbrush at night due to a very noisy compressor I set off on a task to build a nearly silent one. I built this compressor about two years ago.

Here is a list of the major parts I used in building my compressor.

Refrigerator compressor (I salvaged mine from a mini fridge that wouldn’t stay cold) (left)

A pressure regulator (110Psi was more than enough for hobby painting) (left)

Pressure cut off switch  (left)

Air Tank (left)

If you are salvaging a compressor from a refrigerator, It is extremely important to properly evacuate all refrigerant from your donor refrigerator's system. Many shops will do this for free.

Cut the two copper tubes coming from the sealed compressor, Make sure to leave as much of the tube as possible. Once cut, avoid turning the unit upside down. Or the oil will spill out.

Follow the power cord into the wiring harness tracing the wires to their separate terminals on the capacitor. Mark both wires and terminals with masking tape or a marking pen to keep their proper configuration. Make note of wires at this location that will go to another set of terminals on 110v sealed compressor module (or "pump"), tape and mark these wires and terminals as well.

Remove the wiring to everything else except the capacitor and pump. Remove the compressor for the donor refrigerator. Save the rubber feet, they will help reduce noise and vibration when you mount the compressor to its new frame. Connect corresponding power cord wires to the capacitor and green ground wire to base of pump.

Gently bend both copper lines on the pump to point vertically. This will help keep the oil from spitting out or making its way down your feed line into your pressure vessel once it’s attached. Make sure the compressor is secured to prevent "lurching" or pulling wires loose from vibrations.

Plug it in and listen for motor sound: If the unit does not run, unplug it at once and check power cord wires. Note, one copper tube may spit oil at first. This is normal mark this tube as the supply line.

If no oil blows out as the unit is running, put a finger tip on the end of one of the copper lines and feel for the side blowing air. The line blowing air is the supply line and should be marked as such. 8

Following the diagram below and using the appropriate brass fittings and air hose connect the compressor supply line to a 3 way tee. On one end of the tee you will have your air tank with safety pressure release valve. On the other end connect air hose to a second tee with the Pressure Switch and pressure regulator. Finally, attach a quick disconnect to the pressure regulator.

Follow the wiring diagram for your pressure switch and connect the wires from the compressor as well as a grounded power cord.

For The air compressor intake you should install an air filter.

Or if you’re in a bind a wiffle ball at the end of the copper intake pipe with a coffee filter wrapped around it. This worked for me for the first few weeks.

Using the original rubber mounts and making it as level as possible, bolt the pump to a sturdy frame or base plate. I decided to make a nice wood box that sits over the 10 gallon air tank.

This compressor won't win any awards for its looks, but it's silent, cheap and fun to build. I plan to use what I have learned from this project on my next DIY, a silent vacuum chamber for investing.

Running water!

I now have a deep well sink with running water in my shop!!! This is going to make casting and cleanup so much easier!

Project Status 1

I am going to do a weekly readers digest version of the status of my projects! This will not have any pictures and is just an idea of when stuff will get done.

Ruined Castle Gate:

The air compressor has stalled my progress here however the piece is done other then painting and final detail work. I am borrowing an air compressor and hope to have the piece done in the next couple days.

Gardens of Morr:

I have 2 of the buildings finished painting and almost complete with the main gate, just a couple details to add there. Once the air brush is working again I plan to do the first 2 coats of paint with the air brush for the remaining pieces which should save me time overall. Hopefully I will be done with the piece middle of next week.

Minas Tirith:

Working on designing the Citadel. I hope to have some sketches up soon of this and begin construction.

Gazebos:

I am still working on the dome pieces and have not made any progress here. Been focusing on casting blocks and working out kinks in that process.

Workspace:

I have more poly bins to mount to finish sorting. Also this weekend I will be installing a sink basin and running water to the shop. This will make things a lot easier. Also need to mount some peg board by my new bench.

Tools:

I made a couple table tops for casting on which are working well. I have the foam to use as a dampener for the vibration table but have yet to fix that. Might get to that this weekend but probably won't happen till next week.

Lots of stuff going on time to complete some of it!

More poly bins required

I have 40 but probably will need close to 100 to sort all of these blocks.

Weekend Update...

Quick weekend update. I have spent most of my time organizing and casting. I am borrowing a few molds from a fellow wargames terrain enthusiest. This puts me at 16 molds being cast at a time. Below are some pictures of one of the casts and the workspace updates. Here are the molds all layed out ready for pooring.

Here is the bowl of plaster ready to poor...

And all the molds filled but not scraped yet

The corner of the shop where I built a new bench.

New bench and some poly bins are installed.

Tons of blocks ready to be sorted.

Success!!!

So the problems I was having with the UltraCal30 seem to have been solved. I made the mix incredibly thick, a little bit thicker than pancake batter and the pieces were able to be demolded without breaking the details!!! Awesome Sauce!!! I still have some issues with air bubbles but nothing I am not also experiencing with the Merlins Magic. Also some of the pieces I cast earlier with the UltraCal30 have gotten incredibly hard. So it looks like I just need to refine the curing process to get the results I want. I am thinking about using some heat lamps in my paint booth to cure the blocks faster.

With all that said I realize that trying to do this project at my hobby desk in my home office is just not possible. So I will be cleaning up and re-organizing my shop to make this process better.

Hump Day Planning

So it is Wednesday this means I should probably plan out what I want to accomplish by the end of the weekend. Most of the work will likely be done this weekend but I will probably try and knock out a few things tonight and tomorrow if I have time.

1) Finish Vibration Table Project (2hrs)
2) Mount organization bins to workspace (30min)
3) Move Cable Organization (45min)
4) Mount peg boards in workspace (2hrs)
5) Pickup Dental Plaster from post office (1hr)
5) Begin casting pieces (21hrs)
Note: I have calculated I will need to do at least 42 casts of the octagon tower to build the gate checkpoint. This is because of the number of floor sections I will need. Obviously this will provide me with plenty of extra bricks to do other projects. I will likely work on completing the organization tasks while the casts are drying to save time.

Looks like I have a lot to do this weekend...

Workspace: Before

I am going to be doing a series of posts on organizing the workspace. However before I go into step by step details of those projects it is probably important that you see some pictures of how my workspace is starting out.

As you can see there is not a lot of space to work with here. The overall dimensions of the workspace are 32" x 47" which is just big enough to fit the small desk you see. This will be my primary workstation as it is in my house and warm. I do have some space in the garage that I will be using for some of the projects.