Tiny & Powerful Air Compressor Made With a Fridge & Extinguisher Tank

Hi Makers, I just finished making this compressor and i thought in publishing it on instructables just now. I'll try to explain the process the best cause i don't have photos of it.

I made this tool for my cousing as they had a broken fridge on their house and he told me they dont want to repair it. I also want to make one for myself, cause i saw videos of this compressors going over 40 - 60 bars, it is really quiet and it also works as a useful vacuum pump.

For my configuration I used:

- Fridge compressor

- Car extinguisher (You can use any tank, for example a propane tank)

- Air pressure hose (I bought three meters of one rated to 150 psi)

- X2 Pipe fitting, tee, 1/4" NPT female

- Pipe fitting,1/4" male x 1/8" male NPT hex nipple reducer

- X2 Pipe fitting, hex nipple, 1/4" NPT male

- Pressure gauge (mine has and input and an output)

- x2 Male hose barb

- Female hose barb

- x6 Hose Clamps

- X2 Long zip ties (mine are 41 inch long)

- x4 3 inch long screws with nuts

- Wood screws

- Wood board, mine is 1 x 4 inch (the length depends on the size of the compressor)

- Air filter

- Quick release compressed air fittings

- Electrical tape and heat shrink

- Teflon tape

- On-off switch (mine is for 20Amps, i used one rated for 10 but i think it would end up damaging)

- Tools for compressed air (i have an spray gun and an air nozzle for tires)

TOOLS:

- Screwdrivers

- drill with bits

- jigsaw

- Wrenches

- scalpel and scissors

- measuring tape

Get the compressor out of your fridge, you have to carefuly cut the compressor pipes as you dont want to chop it and get little pieces of coper on your compressor. Open the little wire box and you can clearly see the earth connected to the body of the compressor and other two wires. Connect it to AC and see if it works. Put your fingers over the pipes and see wich one is pressure and vacuum.

I used a car extinguisher as a tank, it is really small but my cousin already had it. You need to take the cap of the extinguisher off, i used a big wrench to do this. Remove all the stickers and clean inside and outside nicely. As it'll be exposed to air and humidity you need to paint it inside with an anti corrosion spray to prevent oxidation. As i didn't use an compressor pressure switch i just used a safety relief valve, as this fridge compressors can go to really high pressure and the tank was rated to 150 psi (10 bar aprox). The little pressure gauge of my extinguisher only mark as full or empty so i didn't use it.

Cut your wood according to the size of your parts to make the base, mine was like 12 x 9 inch. Put the longer pieces on top and put the wood screws from the bottom (put at least two on each corner and look that they are not in the way of the mounting holes for the compressor and leave space for the weels). Measure and drill the holes for mounting the compressor and mount the wheels on the corner with at least two wood screws.

On my case my extinguisher had one of the holes with a different thread so i had to put a screw to cover it and use the hole from the pressure gauge from the extinguisher. It had just a little hole for meassuring the preasure, i had to drill a hole so i can use it as an air output/input. Its thread was 1/8" then i had to use a male nipple reducer 1/4" to 1/8". You need to check all the parts for your tank configuration.

Mount your compressor with four screws and nuts. I almost leave the holes out of the board. You can see in the drawing as i assembled the pipes and the extinguisher's nozzle, use teflon tape to seal averything well. I had to use a liquid thread sealant on the screw on the extinguisher, cause it had a leak and that was the only solution.

Mount your extinguisher with everything already assembled and tied, use the zip ties to attach the extingisher to the board. Cut your hose to the right length from the compressor output to the tank input, use electrical tape around the compressor pipe to fit the hose better and tie with pipe clamps. I put an air filter on the vacuum side of the compressor and attached it with a little piece of hose and pipe clamps

I used a female quick release conector so i had to put a male hose barb on it, connect it to the tank output with a long hose and tie it well with pipe clamps.

Try to fit your switch on the wire box (if it doesn't fit you need to put it outside). drill a hole for your switch and connect it breaking one of the AC wires, install and close.

Hope you find my project interesting and it inspired you to make you own compressor. You'll probably use diferent materials as this was the materials i had and i was able to buy on my town.

If you have any question, just ask.

Hope to come back soon with another project. Thanks for your time.