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Old 02-27-2005, 09:25 PM
goleafsgo_12 goleafsgo_12 is offline
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Custom Air Compressor Guide

Ok guys, here is my brand new air compressor setup. I went to princess auto today, and bought 2 small compressors. The specs are: 2hp motor, 5.2cfm and 40psi, 4.2cfm and 90psi, one compressor has a 4 and the other a 5 gallon tank. They are the exact same compressor but I had got the other one a while ago, and this one was on sale now. So, with that said the 5 gallon was 144.44 (cdn dollars) and the 4 gallon 122.22 (cdn dollars).

I picked up a propane tank from a friend of mine. This tank was a 100lb tank, and was previously used for propane. This was used as an external tank to hold more volume of air. Then opened up the valve when nobody was around (becuase even an empty tank stinks something serious) and let all of the excess gas out of the tank. Then I removed the entire valve unit with a pipe wrench, tapping te wrench with a slede hammer when needed. DO NOT hit the valve with the hammer as you will probably do nothing but damage the tank. Anyways, I removed the valve so that only the threads that are cut into the tank were left. Since this tank was fairly large, it had 3/4" NPT (national pipe thread) threads. I left the tank with the valve off outside in the backyard for 3 days, at which point it still stank terrible. Filling it with soap and water, letting it sit and swish around, and dumping it does help.

Then I moved onto the compressors. Everything that I did was done to both compressors. I removed the regulator that control airflow to the tool so that maximum air could be sent to the external tank. I bought 2 air lines roughly 60" long with male ends on both. My compressor, like many, uses a 3/8" ID hose with 1/4" NPT fittings. So i bought a line for each compressor with those specs.

From the compressor, with the new lines, they run into a T fitting (1/4" NPT female ends). This connects both compressors together. From the T fitting it ran into a 1/4" NPT close nipple. From the nipple it ran into to a 1/2" NPT to 1/4" NPT reducer. From there I went from the 1/2" reducer into a 3/4" npt to 1/2" NPT reducer. I would have preffered to go right from a 3/4 reducer to a 1/4 reducer but they didnt have it in stock. So I had to make shift. However it all works the same, its just an extra fittng that you have to purchase. From that 3/4" reducer, it went into a 3/4" NPT, T fitting.

Out the bottom of the T fitting goes a 3/4" NPT nipple into the tank. On the other side of the T fitting, a 3/4" NPT to 1/2" NPT reducer, then into a 1/2" NPT to 1/4" NPT reducer. Out of the 1/4" hole goes the regulator that I took off of one of the compressors. This has an air preassure regulator, and a line cut off valve in one peice. I reccomend putting a quick connect nipple on the end of that, and a quick connect fittng (the one you pull back and slide on) to join the 2. I say this becuase there is no drain valve to remove moisture that collects in the tank. The moisture needs to be drained just like every other compressor. If you dont put the quick connect on, then you will have to remove the fitting by wrench every time. Spend the 2 dollars, buy a fitting, and be done with it. You connect your air line on to the end of the regulator.

Now, the great big tank gets charged by the 2 little compressors, thus giving me WAY more volume for extended air tool activity. The cfm capabillities also doube, now giving me 8.4cfm@90 and 10.4cfm@40psi.

Sure you can go out and buy a tank, with a say 5hp motor, and 30 gallon tank, and its gona cost you 550 bucks or whatever the cost may be. These compressors cost me 266.66 total (together) and they are pretty good for what they put out imo. The fittings were lets call it 20 bucks and the tank was free for me, but you can find tanks for free, usually the small ones just about anywhere. Even if you have to buy one, give it to your neighbour, let him use it in his bbq for a while until its empty and use a small one. Just use the fittings that fit it accordingly to make it work for your setup.. You can daisy chain tanks aswell for even MORE volume if needed.

I did have to remove the top cap that protects the valve to spin on all of my fittings. A word of advice, fill the tank RIGHT FULL with water before grinding off the protector. AND this is very important!! DO NOT GRIND THE WELD THAT HOLDS THIS PROTECTOR ON!!!! these tanks are preassure tested, and done so with this protector on. A lot of people will go to far with the grinder and remove to much metal, thus cutting into the tank and making it unsafe. I ground the protector off above the weld, so the weld seem is still there. I will probably remove it with a flap disc so its smooth, if I dont just put the protector back on in its spot that it was originally welding only ON TOP of the little tabs sticking off the tank. Weld quickly if you have to, but do not weld on the tank, tabs only. I thought the tank was emptied as it had been open for a few days and filled with water a couple times, so i stuck a torch to it. Residual gasses still lit on fire, and made one hell of a bang. However, do be sure that the tank is empty before grinding on it a little becuase its even worse when your face is over the opening and it goes off. This is why im saying fill it with water while grinding.

Tha tank will still stink of propane for a while, but it will clear out with the charging of the tank. AND make sure all joints are teflon taped (or thread sled with special sealent) for a leak proof seal. The best way to test is get it all set up, charge the tank to some sort of pressure, 30psi or 100 psi, doesnt matter, just something. Then pour soupy water over all of the joints, if it bubbles up, you have a leak. Then tighten or retape your joints if need be.

Pictures of this can be found here:

Its a clubphoto account so I cant put pics while I type, sorry guys.
Well, what do you guys think??

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