Air compressor fun with free stuff

My wife doesn't get this but I figure people here will. I've been having fun with compressors.

Last spring a buddy of mine moved his construction company into a new (to him) shop. The previous tenants had left quite a bit of junk in the place including 3 lower end 80 gallon air compressors in various states of disrepair. My buddy was going to dump the lot of them so I got my father out their and we took all of them back to his place.

I can't figure out why someone wanted to just dump them. One is a 4hp (12 cfm @ 90) 2 stage V-twin Husky. The other two were Coleman single stage, 3 cylinder 4.7hp models. Looking them up the Husky ran about $1200, the other two about $900.

My father used to have a large compressor (80 gallon, true 5hp Champion I think) but for the last 20 years or so he's been using a much smaller compressor that's starting to die. Since he was already thinking about a new compressor, a free upgrade to something that's about 80% of what he used to have was a winner.

So what was wrong? Well the compressor used to have a regulator and air fittings on the front under the pump. Those had been smashed the supply line to that panel was never capped. With a simple cap, some cleaning and the addition of a tank pressure gauge (smashed with the panel) the thing is up and running.


My brother and I put one of the Coleman's back together last weekend. As best I can tell one was dropped on the pump (cracked pump) while the other had a replacement 2 cylinder 3hp HF pump and a smashed pressure switch. So we mixed and matched parts to get the 3 hp paired with the good pressure switch. Net result was something that is about as powerful as the "3hp", 60 gallon home improvement store stuff but with an 80 gallon tank.

These aren't big projects but they were fun and satisfying when completed. I'm trying to decide if I want to build up the last compressor. I've got a good 4.7hp motor and tank. I would need a new pump, the various bits of connecting plumbing, a pressure switch and odds and ends. I figure that would cost me $200.

Sadly, for the moment I have neither the space nor sufficient electrical running to my garage (the buried cable is 12/3 with only 120V connected... anything more than 20amp, 240V is a big project). I also really have no need for such a big compressor... but I'm sure if I had it I would invent needs

Anyway, just felt like sharing!

It's amazing what people pitch!
Glad you were able to salvage them!

We need pictures !

I don't have after pictures but here are some before (mostly shot so I could look up the model numbers etc).

What I don't get is why they were taken out of service. The one that had the damaged pump was obvious. The one with the damaged pressure switch seemed fine after clean up. Yes, the pressure switch was damaged but I'm not sure that happened in use. The old company might have run them too hard (hence the HF replacement pump) but if that was the case I would expect the pumps to be shot. I pulled the head on the HF pump just in case since it sounded a bit odd when I turned it by hand at first.

Well it looks like you made out great.

Congrats on the nice saves! Common sense, a willingness to work, and a father and son working together. Best damn story I have read all week. Thanks for posting.

Well we got the system up and running in my brother's garage and did some air distribution on the cheap. Before judging the system remember he has likely less than $50 in this entire install and prior to this he was, other than noise, generally happy with one of these:
https://www.searsoutlet.com/7-gal-A...k/d/product_details.jsp?pid=14525&mode=seeAll
However, it was overwhelmed (but surprisingly not by much) when he was trying to spray a guitar he was making. Anyway, here are pictures of the install. Note these aren't good and some are screen captures from a shaky video.

The replacement finger guard (white) is made from some wire shelving. The black part is the original guard. The wall switch is a 30A switch that is redundant. The primary switch is the one on the pressure switch. Hey, this is a low end 80 gallon compressor so it doesn't have a fancy magnetic starter. The motor is rated at something like 18 amps and we aren't using the wall switch to actually switch the motor in use.

Hydraulic hose goes to the manifold on the wall. There is a shut off valve and regulator. Since this was a system on the cheap we used a PCV air hose (not PVC pipe) to "plumb" the remote fittings. The hose is threaded into the manifold (no coupler losses). The run through the rafters is done so there is a single high point and any water will drain either to the drain leg by the compressor or in the filter/trap at the other end. The PVC hose was 50ft but we cut it down to about 30ft. The remote end hangs about 7 feet off the ground so its above the head but easy. I would like to add some rope/cord to it so tension on the couplers is carried by something other than the air hose and it's joints. We're realistic about the flow restrictions in our "plumbing". Most of the stuff is 1/2" or 3/8" but I figure the losses are no worse than running a 50' air 3/8" air hose (well, depending on the restriction due to that in line filter).

Given the tools he is thinking about using I don't think any of the restrictions will be significant unless a blast cabinet is in the future.

Anyway, it was fun to freecycle the compressor and do the rest for a price low enough that we don't have to justify it. I'm sure new air tool needs will be invented.

I'm going to post a follow up to this story. I started with three compressors. One went to Dad, one to my older brother. The third now lives out west with my little brother. The one with the 3 cylinder pump took the hardest hit of the bunch. The pump had damage, some of the plumbing was missing and the pressure switch was gone. My younger brother wants to get into some fabrication work and figured a "free" compressor would be a great upgrade from his 120V model. So the tank and motor went out West. He added a new pressure switch, plumbing and the like. For a pump he decided to use the "5hp" HF pump but run it at a lower speed and lower peak pressure to avoid overloading the "4.7 hp" motor (18A so probably around 4). I haven't seen the pictures but he said it works nicely. Always nice to see tools get put back into service.

Incidentally, I thanked my buddy for these compressors by giving him a 4 gal DeWalt/Emglo compressor I had fixed. Sadly some #@%! stole it from his shop in short order.