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z28camaro69
08-26-2013, 10:27 PM
I bought a Kobalt 3.7HP 60 gallon compressor about 3-4 years ago, mostly because it was convenient at the time. Now I would like to have more cfm's. Anyone know if I could just buy a two stage pump and use my existing motor and tank? Is 3.7HP 230V SP 15A motor too small for a two stage pump?

GregWeld
08-27-2013, 07:20 PM
The tank is a tank --- as long as it's RATED for the psi you plan to make....


The reason that twin piston compressors come with higher rated motors -- it takes more motor to make more air....


Here's the trick that most people miss. You must look at your air tools - owned and planned to own -- and see what CFM @ what PSI they require to operate. It's easy enough to find with Google etc these days....


Here's my personal feeling about what you're thinking about doing... it may end up costing you more effort and dollars and you might still be sadly lacking. I'd SELL the current compressor --- and just buy one that will do what you need it to do. Look for a compressor rated to make the PSI @ the CFM you're going to need. They're not all that expensive -- but my guess is -- it'll be 220V.
A decent compressor is something you're going to use for the rest of your life -- and always has some value if you decide to sell it.

BBC71Nova
08-27-2013, 07:40 PM
I just went through similar decision process. I sold my old compressor on craigslist within hours. I probably had 20 inquiries afterwards to. They bring good money as long as they are in good operating condition. You may be surprised that you can get about what you probably paid for that Kobalt back out of it. I wouldn't be surprised at all if you could get 300 or so for it.

Spend some time over on GarageJournal. Tons of compressor info over there.

They say Quincy makes a really good compressor if you can spring for it. A 2 stage 5hp(running) would be a nice setup for a home shop and likely more than anyone would ever really need. You just have to make sure your wiring is able to support the draw of the larger motors.

GregWeld
08-27-2013, 07:48 PM
I personally have a single stage 5hp commercial compressor.... so the right single stage will do just fine IF it's rated for what your equipment needs... that's the key.


Most home guys are never going to wear out a compressor -- so as far as I'm concerned -- it's not necessary to spend big bucks on a high end brand (I did only because I have a buddy in the compressor business!) --- just as long as it makes the air needed.

z28camaro69
08-27-2013, 09:02 PM
I think you guys are right, probably not worth the effort to try and upgrade mine and chances are I wouldn't be happy with the air output. Better off spending the money and being done with it. Thanks

GregWeld
08-28-2013, 06:14 AM
That's the proper conclusion. Sell one - buy what you need. Painful because it's not actual car parts - but it's a tool to be used for many many years to come. Think of it as an investment in your hobby.

jonna
09-13-2013, 08:34 AM
A bit on the topic, but we are contemplating replacing our existing compressor, it is an upright\vertical Craftsman compressor (I belive we got a 30 gallon), works very well for us, but it is sooooo noisy:headspin:

Any suggestions? Goal is noise reduction, and stay within similar pressure and volume range. Normally just used for air tools, and plasma cutting, not paint.

Thank you!

J.

renegade6
09-13-2013, 10:18 AM
It sounds like you have a pistonless compressor and those things are crazy noisy. I decided up upgrade and found a used but, unused twin stage 80 gallon for $500.

What a difference! I can hear myself think even with the compressor running and I can normally get a lot of air before the compressor kicks on. I suppose this is a long way of saying; buy as big of a compressor as you can afford, the power savings and not having to wait for it to air up will make it worth it.