# Neglected 60gal compressor repair+testing (Quincy QE-5 1989)



## FliesLikeABrick (Jun 3, 2021)

Hi team,

This past weekend I was out at a persistent yard sale type of place near home, and found a compressor between two of the owner's outbuildings, near some of the decor/items they were selling.  I asked the owner if he was selling it - he said he wasn't, but he would sell it for $400.  He said the story we've all heard before -- last he knew it ran, it had been sitting for 4-5 years, he stopped using it because he didn't need one so big.

I asked him if I could go get my truck and some tools, and if he could move it closer to his breaker panel so I could test it.  He said sure, he had a forklift and it was sitting on a pallet.  He mentioned he had an open 30a breaker but I'd need to bring some wire.

I popped home after  we were done browsing, grabbed various hand tools and borrowed the 10/4 cable from my generator cordset, and headed back.

Unfortunately after 15 minutes, I found the following:
- He had an equally large compressor in his shop near the breaker panel....
- Cloudy oil full of water
- After removing the belt, the compressor would not make a full turn by hand (suspected rust in one of the cylinders)
- In the junction box, the wire nuts were melted right off the junctions...
- and the tank had at least 14 inches of water in it (water came out the plumbing that was near the bottom of the tank, and the drain cock was mostly clogged)

My prognosis was that it may have had a bad capacitor, failed to start, and sat drawing locked-rotor current long enough to burn something up in the motor.

I told him with all this, I wasn't going to try putting power on it, it would damage the compressor or burn up what is left of the motor.  I offered him $50, because I could spend more time on it at home, and worst case make a smoker out of the tank.

He agreed, since it had been sitting and I showed him evidence of all these issues (including one of the capacitors being substantially out of spec)

We loaded it up, I got it home, and spent the next few days dabbling with it.  There were of course 4 main things to figure out, in roughly this order:
- Can the compressor be repaired?
- Will the motor run?
- Can the tank safely hold pressure?
- Can the compressor build sufficient pressure?


Loaded up in the trailer - dropped in with his forklift (I also bought a few tools he had in his barn-o-crap for sale, an older set of 18" bolt cutters, vise grips, and small Krauter lineman pliers)




Once home, I was going to leave it on the trailer for a few days until I had my chain hoist set up to lift it off the trailer.  However, we ended up picking up some free used lumber from someone locally and needed the trailer for that.  So I used a manual winch to slide the compressor out of the trailer and onto my pallet jack - the tailgate of the trailer was resting on a pallet to keep the incline shallower, and I raised the pallet forks up to meet the compressor's pallet sliding out.  Doing this myself, I used ratchet straps to limit the possible travel at a single point in time, in case the compressor started to tip towards me.  Slow and steady, but limited personal risk...





I was eager to get my answer about the compressor, and sure enough, the 2nd-stage bore was rusted and limited rotation of the crank



I let that sit with some rags soaked in evaporust.  While that was sitting I turned my attention to the motor.




Here are the melted wire nuts.  I was optimistic when I realized that the conductors leading to the windings themselves did not feel brittle as if they had been overheated.  The feed wire coming in was 8ga aluminum -- I started to wonder if their under-sized wire nut was leading to a poor connection and arcing/overheating, at least once the motor aged?  Maybe the motor is ok....



I tested the windings, and found what seemed like reasonable resistances.  I believe it was approximately 1.8 ohms and 3.2 ohms -- seems reasonable for a start winding and main winding?    The 2 older capacitors tested within spec, but the newer metal one at the top was out of spec though not completely open or shorted.

Good enough to try giving it a run.  But wait a minute.... the compressor needs to rotate CCW.  The motor, when I received it, was wired for CW rotation.  Odd, another indicator the previous owner may not have taken proper care when making changes or repairs to this over time.  Maybe this got shelved due to some misunderstanding or concern and not catastrophic failure?

Testing the motor with the belt off, and I had to bypass the pressure switch which is in need of TLC or replacement -- 100a inrush, 19a no load.  A bit high for a motor rated at 21 FLA, but it runs -- and perhaps either the centrifugal switch is stuck or the capacitor being out of spec is causing inefficiency; both warrant further investigation later.




So the motor is healthy enough, let's look back to the compressor.

After evporust rag treatment (which I was too impatient for), I hit it with a stainless steel brush and then a small engine cylinder hone with some penetrating oil as lubricant.  I stopped a couple times to freshen up/unclog the stones on a coarse diamond stone.  This turned out reasonably.  I went over it 5-10 times with light oil and a rag, turning the compressor by hand to try and get as much rust and stone debris out of the cylinder and rings.  If this runs well and I can get a gasket set for this compressor, I'll pull it apart and give it a proper cleaning further in the future.



So now the tank.  Rated for 200 psi MAWP (the compressor was rated for 175 psi cut-out when it was new), I am skeptical of trusting a pressure vessel this large inherently.  I wanted to use Keith Rucker's approach -- using water and a pressure washer to DIY re-certify it.  I decided I would like to take it up to 225-250psi in such a test.




Long story short, I set it up with a 3/8 pressure washer quick connect adapted onto the outlet hardware. I disconnected the tank inlet and pressure switch, replacing them with a plug and reliable gauge, respectively.  Filling the tank from the pressure washer, I closed the top plug once water started coming out.  At 1atm I estimate I had well under 1/2 gallon of air remaining in the system.  At 200+ PSI, this was a level of stored energy I was ok with albeit still leery of.






The compressor was moved just outside the garage for the test, so I ran a 3/8 hose to a compression tester gauge just inside the door.  I built ~40 psi of pressure and confirmed that the two gauges agreed, to avoid any bad readings/assumptions about the state o the system.

With earplugs, a face shield, a heavy shop apron, and a garage door as protection - I built pressure to ~240 psi and let it hold for 20 minutes before relieving pressure and draining the tank













OK! All major components are showing promise.

The last step is to test the system -- can the compressor build respectable pressure?
As the water was draining out of the tank, I started reattaching the compressor to the tank and running power from the breaker panel back to the motor.

Assuming the same position behind the garage door, but this time with the multimeter showing the current as load built (so I could cut it off if it became unhealthy), I began running the compressor.   There was one false start where the safety valve or the unloader valve on the pressure switch (which I had reattached) started leaking around 100psi, so I removed them again and plugged that orifice temporarily instead.  Resuming my position in the garage, behind a structural element next to the garage door -- just in case...




Built pressure steadily to 160psi -- and it held,  as it should after the 240psi water test.




I bled off some pressure and ran the compressor more, with the dipstick removed from the crankcase.  I did not feel any significant blowby coming out - just a pulse due to the asymmetric piston sizes between the separate stages.

So at this point I should have a working compressor, which I'll probably run 125/150 psi instead of the original 175 psi that it was rated for in 1989.

Remaining steps:
- A couple oil changes to eliminate the moisture from the crankcase
- New belt and filter, then reinstall guards (Which I do have, but were removed during inspection at the seller's place)
- The motor drew more current than I'd like under load, up to 28-29 amps.  I will get a new capacitor for the one I am skeptical of, and see if I can find specs for the windings in this motor.  The motor bearings feel/sound fine.
- Pressure switch is missing its cover and needs cleaning+adjustment after being exposed to the elements.  I will probably replace it instead
- One or both safety valves may need to be replaced.  I may do this anyway, since I'd install 175 psi safety valves (it probably came with 200, and after being exposed to the elements for years I'm not sure I want to trust them).
- I have talked to a Quincy dealer about parts availability and am seeing if I can get a gasket set so that I can tear this down for full cleaning of the 2nd stage cylinder+rings without worrying about damaging the gaskets.  However, this is expensive and may not be readily available -- so we'll see.
- I would like to time how long it takes to build from 0 to 50psi and see if it gets better over the coming weeks (rings conforming to the 2nd stage cylinder after honing), or worse (I left behind grit/debris that is damaging the cylinder), but this difference may be too little to measure.
- When I get ready to plumb this into the shop, I'll pull the previous owner's output plumbing off and stick a borescope in to see what the inside of the tank looks like.  Hopefully we'll see surface rust and no major flaking or structural risk.

Thanks for reading, I am open to any constructive criticism and welcome any insight/knowledge!


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## FOMOGO (Jun 3, 2021)

There is a place in Washington state that has complete rebuild kits for any Quincy compressor, for reasonable money. Cant remember the name off hand, but I'm sure they would be cheaper than a dealer. Should be able to find it with a little Google search. Those are great pumps, should last you a lifetime. Mike


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## Papa Charlie (Jun 3, 2021)

Very nice find. Once you have gone through it, you will have a unit that will most likely out last you. 

One recommendation, I would create a pad outside of your shop to mount it and put a cover over it. With the tank being this old and filled with water for some time, your hydro test will only tell you at this moment that the tank is good. But not how long it will be. You could have pin holes that may hold pressure now and will continue to bore into the metal and well you know what happens. By placing it outside, away from your work area, you add a level of safety just in case. These tanks rarely give you any warning. 

The compressor and motor, are hardy enough that you could easily rebuild or service and not have any worries. I would assume that if you break down the motor you will find there is a lot of debris that is causing the additional load. A simple cleaning of the windings, rotor and stator could go a long ways to correcting some of your issues, along with the capacitor and wiring.


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## brino (Jun 3, 2021)

I really appreciate your logical and methodical and safety-minded approach.

Thanks for posting with such detail and photos.

-brino


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## FliesLikeABrick (Jun 3, 2021)

Papa Charlie said:


> One recommendation, I would create a pad outside of your shop to mount it and put a cover over it. With the tank being this old and filled with water for some time, your hydro test will only tell you at this moment that the tank is good. But not how long it will be. You could have pin holes that may hold pressure now and will continue to bore into the metal and well you know what happens. By placing it outside, away from your work area, you add a level of safety just in case. These tanks rarely give you any warning.


Indeed, I have considered this.  I think it will go in the garage for now (which is not a primary shop work area).  However in the future if I have a storage container outside (which may partially provide a paint booth), the compressor could get moved out there.  We have pretty high humidity in Northern VA in the summer though, so I do prefer to keep it indoors where the dehumidifier is for longevity -- but that may be over-optimizing. Or maybe I put a dehumidifier in the storage container, who knows! \o/



Papa Charlie said:


> The compressor and motor, are hardy enough that you could easily rebuild or service and not have any worries. I would assume that if you break down the motor you will find there is a lot of debris that is causing the additional load. A simple cleaning of the windings, rotor and stator could go a long ways to correcting some of your issues, along with the capacitor and wiring.


Can you share a bit more about what to look for in the motor, and how those findings contribute to higher load?


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## Papa Charlie (Jun 3, 2021)

Excessive dirt, grit, oils, etc that are in the air in shops gets pulled into the motors through their cooling fans. This builds up creating an insulator and causes resistance.
It doesn't take much to pull the end caps and double check if there is an issue in the motor and then to clean it should you find anything. There are plenty of examples on YouTube on how t do this.

Here is a link to an interesting report:


			https://www.energy.gov/sites/prod/files/2014/04/f15/mc-0381.pdf


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## FliesLikeABrick (Jun 3, 2021)

Papa Charlie said:


> Excessive dirt, grit, oils, etc that are in the air in shops gets pulled into the motors through their cooling fans. This builds up and causes resistance.
> It doesn't take much to pull the end caps and double check if there is an issue in the motor and then to clean it should you find anything. There are plenty of examples on YouTube on how t do this.


Yep make sense - I have overhauled a handful of motors before so I'm happy to pull it apart and see.  This is new to me, that buildup of dust/debris can cause enough resistance to increase current draw significantly, thanks for the insight


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## Papa Charlie (Jun 3, 2021)

FliesLikeABRick said:


> Yep make sense - I have overhauled a handful of motors before so I'm happy to pull it apart and see.  This is new to me, that buildup of dust/debris can cause enough resistance to increase current draw significantly, thanks for the insight


I have seen so much build up in a motor that when we first tore it down, we thought the bearings had locked up. It turned out that there was just too much dirt mixed with the air borne oils from the shop over years that was preventing it from turning. We actually used a steam cleaner on it after we picked at it for a while to get the big chunks out. Then we let it dry in the hot Central California sun for about a week to ensure that everything was good and dry.

The motor shop that we used for rebuilds, use to put them in an oven to bake out any moisture at a fairly low temp, maybe 200F. But they were in a hurry. 

You have to be careful on older motors as they used paper and cloth in the construction. So not always possible to use the steam cleaner with the pressure turned way down, a good soap and of course the hot water.


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## markba633csi (Jun 3, 2021)

Definitely put a protective shroud/wall around the tank, in case it decides to grenade on you
Great find!


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## Tinkershed (Jun 5, 2021)

One thing that might stand you in good stead twice.  I would build a little frame enclosure around it and maybe some standard house insulation  Not only would it protect you in case the the tank decided to let go,  but also it would hold down the noise from the compressor.  If you go this route my recommendation would be to double the code for framing on the side toward the shop, e.g. a stud every 8 inches,  followed by 3/4 inch plywood on the outside.  If the tank lets go it would provide some protection against the fragments getting you.  Obvously a formal pressure test would be better and running it under spec at a max of 125 Lb  would also be a good idea.  Just my 2 cents!


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## jwmay (Jun 6, 2021)

I really never realized people did this.  Thanks for a very interesting and informative post.


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## Papa Charlie (Jun 6, 2021)

jwmay said:


> *I really never realized people did this.*  Thanks for a very interesting and informative post.


Did what? Test air receivers?


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## Cadillac (Jun 6, 2021)

FYI that aluminum foil garage door won’t due a DAM thing if that tank decided to blow.


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## Hellkell (Jun 7, 2021)

Has anyone ever tried putting OSPHO inside a tank? I’ve considered putting it in my Quincy tank but haven’t yet. 

If you built a protective blast box for it I don’t think wood do a bit of good. I think it would be best to use cement blocks filled with concrete.


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## Eddyde (Jun 7, 2021)

I agree that any containment structure built out of wood, would only result in more projectiles...
A well constructed concrete structure with three walls so that the energy would be focused in one direction might work but that kind of hassle makes a new tank a more viable option, IMHO.
That being said, I was a licensed air compressor supervisor in NYC (yes it's required there) for almost 20 years. Our shop had 2 compressors with 3 tanks, one of them ancient. We had the tanks hydrostatic tested roughly every three years. The technician that preformed the tests would fill the tanks with water then hook them up to a tank of nitrogen, pressurize to 300 psi and wait 30 minutes. He'd calmly stand right next to the tanks while doing the test saying that when they go they just make a little pop and the water gushes out, and that was extremely rare.


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## Papa Charlie (Jun 7, 2021)

Eddyde said:


> I agree that any containment structure built out of wood, would only result in more projectiles...
> A well constructed concrete structure with three walls so that the energy would be focused in one direction might work but that kind of hassle makes a new tank a more viable option, IMHO.
> That being said, I was a licensed air compressor supervisor in NYC (yes it's required there) for almost 20 years. Our shop had 2 compressors with 3 tanks, one of them ancient. We had the tanks hydrostatic tested roughly every three years. The technician that preformed the tests would fill the tanks with water then hook them up to a tank of nitrogen, pressurize to 300 psi and wait 30 minutes. He'd calmly stand right next to the tanks while doing the test saying that when they go they just make a little pop and the water gushes out, and that was extremely rare.


That seems logical. The water is much more dense and would restrain the release of energy compared to air.

Here is a comparison between Hydrotest and Pneumatic Test failure. Pretty dramatic comparison.


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## FOMOGO (Jun 7, 2021)

You could just put your compressor in one of these. Lots of them for sale. Not really at the top of my list of things to worry about. Evaluate once and fagitaboutit. I do isolate them for sound reduction. Mike


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## Papa Charlie (Jun 7, 2021)

FOMOGO said:


> You could just put your compressor in one of these. Lots of them for sale. Not really at the top of my list of things to worry about. Evaluate once and fagitaboutit. I do isolate them for sound reduction. Mike
> 
> View attachment 368455


I would like to have one of those to go to the grocery store and the tool auctions. Would make parking and negotiations a lot simpler.


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## jwmay (Jun 7, 2021)

I thought when a compressor stopped working, people put them out in the alley to rot. I didn't realize other people came along and made them work again. I never even considered the possibility.


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## Tinkershed (Jun 8, 2021)

I bow to greater experience when it comes to deflecting fragments although I still believe that some obstacle is better than none.  I expect the real key would be running it a lower than spec pressure.   Considering that the tank was probably tested at over 200 lbs of pressure, running it at 125 or so would likely be fine.  I would certainly do so with that setup.


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## FliesLikeABrick (Jul 31, 2021)

For what it's worth/to close the loop with the group here - after further inspection of the tank, I have decided to try and track down a new 60 or 80 gallon tank that I can transplant all these parts over to.


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## extropic (Jul 31, 2021)

FliesLikeABRick said:


> For what it's worth/to close the loop with the group here - *after further inspection of the tank*, I have decided to try and track down a new 60 or 80 gallon tank that I can transplant all these parts over to.



You successfully hydrotested it to 240 PSIG. What further inspections did you perform and what were your findings that lead to your decision to replace?

I'm not criticizing your decision. I (and I assume others) might learn something from your inspection and decision processes.


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## FliesLikeABrick (Jul 31, 2021)

Thanks for asking --

When I had drained water from it previously, including after hydrotesting it, the tank drain at the bottom kept becoming clogged with pieces of rust or other debris.  I decided to stick my cheap borescope in one of the tank openings and take a look, and saw two things:
- The walls of the tank near the bottom, particularly the welds, didn't look great
- There was so much sludge (presumably 100% rust debris) that I couldn't even find the tank drain at the bottom

I ended up hooking together a bunch of fittings to feed water in, agitate it, and drain out the bottom of the tank.  After doing this with probably 30 gallons of water, I finally got it to run clear -- but not until I had a *lot* of pieces of debris come out with the rust.  Presumably the rusting was more than just surface rusting inside over time leading to rusty water/discharge... but actual solid pieces of rust that made me think bigger pieces were flaking off.

Here are pictures:

junk in bottom of tank before flushing (borescope):




more of the same, notice the larger chunks.  These were large enough to clog the 1/8 NPT boss at the bottom of the tank, even after I removed the fittings







Some of the junk in a bucket after pouring the water off:


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## Flyinfool (Jul 31, 2021)

Are there places to find used 60-80 gallon tanks that are safe? New ones are so expensive.


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## FliesLikeABrick (Jul 31, 2021)

I found a surplus site online that has them new at a reasonable price, but the freight is the killer.  I'm working on trying to find a local business that will let me have it delivered to their place (and drop it in my truck with a forklift) for $50, so that I can save $180 of the freight charge by not needing a liftgate and delivery to a residential area.


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## matthewsx (Jul 31, 2021)

Tinkershed said:


> I bow to greater experience when it comes to deflecting fragments although I still believe that some obstacle is better than none.  I expect the real key would be running it a lower than spec pressure.   Considering that the tank was probably tested at over 200 lbs of pressure, running it at 125 or so would likely be fine.  I would certainly do so with that setup.



I have an older compressor I got from a customer. After talking with the local compressor shop I dropped the max pressure down to 125psi and don't really worry about it.

Yes, they are horrible when the let go but it's a lot more likely with a horizontal tank (more area exposed to water) than a vertical one.

I would run it outside if that's possible with your setup just because it's nicer.

John


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## lordbeezer (Aug 1, 2021)

I cut a lot of compressor tanks open to make grills,smokers. Some are scary rusted thin. Lots of big chunks of rusted metal. I think you made the right decision. Tank would make a good smoker or grill


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## extropic (Aug 1, 2021)

FliesLikeABRick said:


> I found a surplus site online that has them new at a reasonable price, but the freight is the killer.  I'm working on trying to find a local business that will let me have it delivered to their place (and drop it in my truck with a forklift) for $50, so that I can save $180 of the freight charge by not needing a liftgate and delivery to a residential area.



Perhaps you could have the tank delivered to the carriers terminal nearest you (save the $50 and the LTL freight should be the lowest possible). Find out which carrier the seller will use and see if their nearest terminal makes sense for you. They have always loaded onto my pick-up. YMMV.


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## FliesLikeABrick (Aug 1, 2021)

extropic said:


> Perhaps you could have the tank delivered to the carriers terminal nearest you (save the $50 and the LTL freight should be the lowest possible). Find out which carrier the seller will use and see if their nearest terminal makes sense for you. They have always loaded onto my pick-up. YMMV.


Thanks this is an option I had not considered


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## rwm (Aug 1, 2021)

If I ever build my dream shop, I am going to plan on a metal cage to situate the compressor and the dust collection vacuum in a separate closet.
If you watch the video of catastrophic tank failures they do not seem to fragment. More like one or two large flaps of sheet metal to contain.


Robert


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