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Minimum Compressor Size for Automotive Use

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angelfj1

angelfj1

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I have an opportunity to pick up a new compressor at Lowes at a closeout price. I want something to use in my home shop for air tools, painting and for media blasting. The unit I am considering is a Kobalt brand with the following ratings
Model k7045v
45 gallon
135 psi max
3.5 HP, 230 volt
2 cylinder, single-stage cast iron pump
10.1 scfm @ 90 psi
12 scfm @ 40 psi

closeout price $299.

Question, will this be sufficient for my needs?
 
Yes, this unit should do the job and then some. I had a 20 gal and it would run out of poop using a DA sander. The 60 I have now will run it forever. The 45 is a nice compromise without spending BIG bucks. (A sander will probably be the biggest air used you will run into). Bob
 
CAUTION!!!

I think my 6.5HP is only good from 11 CFM @ 90 and 13 CFM @ 40. I'd check the ratings against a couple of other brands before trusting them.

My compressor will keep up with a DA sander, taking no more than the normal amount of breaks to check your work, change paper,...etc. It struggles a bit with my long-board, but that just forces me to take a break that my body needs anyway.

Those two sanmders are probebly the worst-case scenario, unless you want to start sandblasting large things. That's a different league.

That's my $0.02. Your mileage may vary.
 
if it's a Kolbalt, don't buy it. The pulleys come off the motor's shaft and eat the shaft and pulley up.
Been there, done that and replaced it with a Campbell Hausefield.
 
Personally, I'd want a 2-stage unit. The output of the single stage units drops off dramatically above 90 psi; and many air tools want at least 90 psi for proper operation.

I've limped along with a single stage for way too long; next one's got to be 2-stage.

Don't forget that, at 90 psi, there is about a 7:1 ratio between SCFM and ACFM (which is what air tools are rated in). That means your 10.1 SCFM hasn't a hope of keeping up with, for example, a 4 ACFM (roughly 28 SCFM) die grinder. And 135 psi just doesn't give you that long before the tank pressure drops below 90 and tool performance starts to drop off.
 
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