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Technical Minimum size compressor for shop work?

Discussion in 'The Hokey Ass Message Board' started by 34Larry, Mar 5, 2020.

  1. Blue One
    Joined: Feb 6, 2010
    Posts: 11,459

    Blue One
    ALLIANCE MEMBER
    from Alberta

    There’s a joke that goes “I’m so old that I don’t buy green bananas anymore Larry :D

    A Harbor Freight compressor would probably be more than enough and affordable too ;):D
     
    dirty old man, K13 and Flathead Dave like this.
  2. glrbird
    Joined: Dec 20, 2010
    Posts: 601

    glrbird
    Member

    FDA5C217-F5C2-49FE-8D1D-5C3BB77535ED.jpeg
    bought a Lowe’s 80 gal, took 100.00 off for opening a charge and no interest for one year. Little noise but I can live with it.
     
  3. finn
    Joined: Jan 25, 2006
    Posts: 1,280

    finn
    Member

    Don’t get hung up on Quincy. They, like Ingersoll Rand and probably most other manufacturers (or marketers) have several quality levels of compressors. The cheaper ones probably aren’t much better than the box store compressors, while the top of the line units will run tens of thousands of hours, but the buy in price is very steep.

    For a hobbies, a top of the line compressor may be overkill.

    Also, there are other companies with product every bit as good as Quincy, notably Champion and Saylor Beal.

    I normally don’t recommend buying tools used, but I personally picked up a 5hp Ingersoll, albeit the obsolete version that had an aluminum Italian pump, and a new 5hp Marathon motor. Paid $300, and it works fine for light to moderate sandblasting.

    I later picked up a Champion with a professionally rebuilt pump. It’s an older unit and only has a 3 hp motor, but the 80 gallon tank hides a number of sins. That same compressor was sold with a 5 or 7.5 hp motor and rated at somewhere around 20-23 CFPB when so equipped.

    I have painted cars with the Champion with the small motor, but would recommend at least a 5 hp motor and ~15 cam if you are serious about painting and blasting.

    A serious blaster would rent, borrow, or buy a trailer mounted, engine driven compressor. Not practical as your only compressor, but I have seen them go cheap at municipal auctions.
     
  4. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 3,959

    Flathead Dave
    ALLIANCE MEMBER
    from So. Cal.

  5. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 3,959

    Flathead Dave
    ALLIANCE MEMBER
    from So. Cal.

    $500 is pretty good for a rebuild considering what a good new compressor will cost.
    Go to Harbor Freight. They have great deals on their shit.
     
  6. Early Ironman
    Joined: Feb 1, 2016
    Posts: 553

    Early Ironman
    Member

  7. b-body-bob
    Joined: Apr 23, 2011
    Posts: 555

    b-body-bob
    Member

    My BIL owns a quick oil change place, and one day he shows up out of the blue with a disassembled Champion 80 gal, 5 hp compressor in the back of his truck. He said it blows fuses, he couldn't stop working to have it repaired, so he just bought a new one. I said thanks.

    I spent maybe $50 on rebuild parts (since it was apart anyway) and about $250 on a new 5hp motor. This pump was cheap and easy to rebuild.

    [​IMG]
     
    Last edited: Mar 6, 2020
  8. jnaki
    Joined: Jan 1, 2015
    Posts: 9,291

    jnaki

    Hello,
    When I needed more versatility in my household construction projects, I needed a compressor to power some nail guns and staplers. There was space under the counter for the compressor and I was told that 6 gallons would do just fine for what I had planned. We are talking minimal compressor size other than a bicycle pump. But powerful enough to attach any air powered tool if needed.
    upload_2020-3-6_6-55-51.png upload_2020-3-6_6-56-5.png with accesories
    On our old house, this model lasted for several years, but I had to keep the compressor in the cabinet with the door closed, and the garage door closed. It still made a terrible racket. I never used it outdoors. This was strictly inside of the garage with the big door closed. I could stand on the sidewalk and still hear it running. Let alone using the nail gun(s). Speaking of which, those nail gun sounds are almost as bad as leaf blowers in our neighborhood.

    When that model went out, a neighbor said he would take it and try to repair everything. So, I bought a similar model, but slightly quieter. Same tools, same enclosed cabinet, same household projects. But, since our neighborhood is very quiet, I felt awful using this compressor to do any work. So, it went to our niece and her family.
    upload_2020-3-6_6-56-51.png
    Bostitch 6-Gallon Single Stage Portable Electric Pancake Air Compressor still 80 decibels
    I was able to use all air tools, but still made 80 decibels and had to be used inside of a cabinet/garage door closed.

    Now, I was stuck without any compressors for any simple jobs like filling the car tires and when our granddaughter was a little toddler, blowing up various sizes of inflatable, swimming pools.

    Jnaki

    But, as we get older and even back then, in the prime time, 3 car garage, giant workspace areas inside of the garage, noise was a factor in our neighborhood. So, I had to choose when I used the power tools, the air compressors and other equipment, like table saws and band saws.

    Luckily there is our favorite tire store just down the hill and they fill up our tires anytime as a courtesy service. We have always bought our tires from them and it is handy for any repairs or quick services.

    So, now, this new unit is one I have kept in mind as one of our contractors has one and it is super quiet. Lightweight at 35 lbs and only 60 decibels. Remember the original pancake compressor was 80 plus decibels, years ago. At 18.5 x 14 x 13.5 inches, it will fit perfectly inside of our new thicker construction panels of the garage cabinets. That should help the noise factor. But, those future projects are slowly going by the wayside in these relaxing times. So, the new compressor may take a nap for a while in my head.
    upload_2020-3-6_6-58-24.png

    Remember, this is MINIMAL garage usage, not for the full blown dismantling and rebuilding of a rusted out wreck of a car.
     
  9. Gearhead Graphics
    Joined: Oct 4, 2008
    Posts: 3,890

    Gearhead Graphics
    Member
    from Denver Co

    For what a decent replacement is going to cost, 500 to repair the old one thats overkill is probably a good idea
     
  10. Pats55
    Joined: Apr 29, 2013
    Posts: 554

    Pats55
    Member
    from NJ

    Check out Universal Electric Motor in Hackensack New Jersey. You might be better off just changing out the motor.
     
  11. deathrowdave
    Joined: May 27, 2014
    Posts: 3,518

    deathrowdave
    ALLIANCE MEMBER
    from NKy

    I have 5 HP older Quincy , 80 gal horizontal tank . I bought it at a School auction . Rebuilt the pump , and it’s going strong . Quincy , is one of the best , if not the best . Pressurized oil system . 100 % cast iron . I worked on and operated many pipeline compressors in my job. A few were 1750 Hp synchronized electric motor . 250 mcf per hour per end at 8 ends per compressor . By far the most efficient compressor to buy is a screw compressor , they are expensive , but move major amounts of air continuously . Look at the MCF produced , and not the advertised HP when purchasing .
     
  12. MeanGene427
    Joined: Dec 15, 2010
    Posts: 2,307

    MeanGene427
    Member
    from Napa

    If the rest of the compressor is good, why not just replace the motor? Around 1995 I found an I-R T30 in great shape, a pretty good unit, on cl pretty cheap, as it was 3-phase- got it for $300. Next day I found a NIB 5hp Baldor motor, identical except single phase, on epay for $200. Instructions for rewiring are inside the switch box. Still chugging
     
  13. mrbeetle
    Joined: Jan 30, 2017
    Posts: 9

    mrbeetle

    Has anyone else looked at the scroll compressor from Eastwood? Specs show it to be about 12 cfm at 90 so I realize it’s low based on some of the recommendations here, but they also show it being used for soda blasting. I would think a big engine driven compressor would be better for serious blasting, but this one seems like it’d be fine for a home garage and holy cow is it quiet! (There’s an Eastwood store near me, so yes I’ve seen it in person)

    https://www.eastwood.com/eastwood-elite-qst-30-60-scroll-air-compressor.html


    Sent from my iPhone using H.A.M.B.
     
  14. Finn Jensen
    Joined: Dec 20, 2008
    Posts: 675

    Finn Jensen
    ALLIANCE MEMBER

    I'm not a big fan of Harbor Freight, but I wouldn't sell their motors short. The motor in my 2hp Sears compressor, that I bought in 1974, died in 2002. After looking for a replacement motor that I needed quickly, I bought a 3hp motor from Harbor Freight. I wired it for 220 volts. It has operated flawlessly over the last 18 years.
     
  15. 57JoeFoMoPar
    Joined: Sep 14, 2004
    Posts: 6,138

    57JoeFoMoPar
    Member

    I bought an IR 5hp, 80 gallon 220v compressor from Tractor Supply last year. It has been great, and even rigorous use of air sanders hasn't run it down. For $999 new with a warranty, I don't think it can be beat.
     
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  16. 34Larry
    Joined: Apr 25, 2011
    Posts: 1,701

    34Larry
    Member

    I'm digesting what all of you have advised. Yes when the motor dumped it was one of the capacitors. I had that replaced, it ran fine for 30 seconds or so and then smoke appeared like a coal powered locomotive. I wired it just like it came out. I took it back, the winding was cooked. Went looking for the same motor and not being an electrical genius had all kinds of trouble finding one.

    At my age, I won't be using one all that much but you know how it is, when you need one, then you need one. (One note. It is pretty risky for me to get out and about with this coronavirus in our area and being well, well over 60, being diabetic and with heart disease, (replaced aortic valve, 3 way bypass and a stint), the experts are telling me I'm really at risk. So I'm being overly cautious and not leaving the house and yard that much. I've never been in a situation like this and believe me it is extremely concerning.:eek::eek::eek::eek::eek::eek::eek::eek:

    It will however give me some time to A) find the right motor and where it is, or B) decide on a compressor and cost, and compare the two and then make a decision. I, like many have here have suggested would prefer to just replace the motor. The old one is kicking around behind the seat in the Silverado and later I'll go out and bring it in and post what it is and get more advice about replacing it. (I have to have something to do while semi quarantined to my residence). My sincere thanks and I'll be back for more on the motor later. :):D
     
    dirty old man likes this.
  17. MeanGene427
    Joined: Dec 15, 2010
    Posts: 2,307

    MeanGene427
    Member
    from Napa

    In your searching for a motor, you will need the voltage and phasing, and the frame number to match
     
  18. 34Larry
    Joined: Apr 25, 2011
    Posts: 1,701

    34Larry
    Member

    Thanks MeanGene427, when searching before I learned that and I appreciate you reminding me.
     
  19. winduptoy
    Joined: Feb 19, 2013
    Posts: 3,318

    winduptoy
    ALLIANCE MEMBER

    I suspect that the centrifugal switch has stuck contacts (closed, if they were open the motor would just hum and not start). The motor is a capacitor start and when the motor speed spools up, the contacts are supposed to open and take the start capacitors out of the circuit.
    I'd index the motor ends to the case and pull the thing apart, unstick the contacts, file as necessary, lube the switch lightly with some silicone grease (on the shaft). Then I would take my hypodermic needle on the end of the grease gun and work it under the bearing seals and give them a shot. Reassemble and run.
    I'd then take all my buddies to lunch and have $450 dollars left....don't have many buddies
    but that just me....
     
  20. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,589

    Blues4U
    Member
    from So Cal

    When I read these posts of how long some of you have had your compressors, it reminds me of the inspections that were required on air compressor tanks used in commercial applications, and why. When I worked in heavy equipment repair we had to have the tanks fo every compressor on every service truck inspected periodically, any that didn't pass inspection had to be replaced. Exploding tanks is a thing, and it can really ruin your day.
    [​IMG]
    [​IMG] [​IMG] [​IMG]
     
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  21. 34Larry
    Joined: Apr 25, 2011
    Posts: 1,701

    34Larry
    Member

    I'm not much on electricity and electric motors especially but I thought when it smoked out that it somehow did not come off the starting capacitors as you have said. Thanks for the suggestion, but that is just a smidge beyond my knowledge, and I'd gladly take you to lunch if you want to meet half way between Seattle and Zuzax, New Mexico.:)
     
    winduptoy likes this.
  22. One of my mom's neighbors had a compressor go off in their garage years ago... thankfully no one was in the building at the time but it put a large dent in the side of their new car. And they had an old battery sitting on the floor in front of the compressor so found out the hard way what acid will do to paint.
     
  23. jaracer
    Joined: Oct 4, 2008
    Posts: 2,419

    jaracer
    Member

    The CFM required for a home shop is the most you can afford. I have a really old Curtis 2 stage out of a filling station on a vertical 80 gallon tank. I traded for it about about 40 years ago and it was at least 30 years old then. It doesn't have enough CFM to keep up with body tools but it keeps on working. I work with body tools till it drops to maybe 60 psi, then let it cycle. Impacts don't really affect it. Painting isn't a problem, but I use the old style Devilbiss gun.
     
  24. I bought a used IR, 5 horse, 220v single phase, 60 gallon vertical tank, 15 years ago and am happy to keep replacing parts or repairing it. I added an IR automatic oil-water dropout valve to the tank and another one in the piping before my spray area and more oil and water control. Piping is rigid copper, 1-1/4”, 1”, 3/4” as it gets further from the tank, with 1/2” service drops.
     
    Last edited: Mar 10, 2020
  25. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,522

    Roothawg
    Member

    57JoeFoMoPar likes this.
  26. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,215

    ekimneirbo

    If you want a decent compressor, first thing to look at is the electric motor. If its a "small" one that says its 5 HP, leave it and run away quickly. The size of the motor and whether it operates at 1725 rpms or 3450 rpms will tell you a lot about the compressor too. The small motors are either overrated or misstated. If its got a "large" motor and runs at 1725 rpms, THEN look at the pump. If you get an aluminum pump, it will look nice and shiny. It most likely won't have real bearings in it and probably won't be a 2 stage pump. It will probably need a pump replacement in the future if the electric motor doesn't fail first. Cast Iron is the best pump and that still doesn't guarantee quality unless you buy a decent one like Quincy,Kellogg,Saylor Beal.
    Bottom line is that if your old compressor works well, I would just look on Ebay for a decent electric replacement motor. Otherwise plan on spending about $2200+
     
    rusty valley and 1934coupe like this.
  27. The way I made my small cheap compressor, all I could afford at the time, act like a big compressor was to go to the scrapyard and buy 3 of those outside propane tanks used at many farmhouses.
    I don't know the gallons etc, but they were the ones that stood about shoulder high, and were about 14 inches diam ? or so.
    I mounted three upside down about halfway up on the shop wall to make sure they never collected water.
    When connected into the air lines on my wall, they gave it enough reserve to imitate a big compressor capacity for a good while, as long as I gave it time to recharge every once in a while.
    If I didnt mind waiting a while for a small compressor to charge a big tank, it would act just like a big air supply for a good while until I needed to let it recharge again.
    That let me run big tools and actually paint a couple of my cars without buying a big compressor I couldnt afford.


    WHY BE ORDINARY ?
     
    caseywheels likes this.
  28. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 5,215

    2OLD2FAST
    Member
    from illinois

    You can replace the motor with something smaller ,gear it down so the compressor runs a bit slower , just slows down the recovery time ,at least until you find a more suitable motor.., you'll have pressure..
     
  29. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 5,215

    2OLD2FAST
    Member
    from illinois

    Another place to look for motors is on farms , some of the conveyor motors are pretty beefy , around here I've found more than one that was good but replaced so the conveyor would go faster ...
     
  30. bigdog
    Joined: Oct 30, 2002
    Posts: 761

    bigdog
    ALLIANCE MEMBER

    A compressor is like a shop building-never big enough. I've got a 5hp, two stage, 18.5 cfm and when I'm sandblasting it isn't big enough. Size matters. More is better.
     

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