Compressor specs questions

[hellfish]

What are the specs required for a car hobbyist limited to 110-120v? I would need a compressor for sanding, grinding, cutting and maybe painting.

I'm looking at a DeWalt on sale with:
Air Delivery SCFM At 40 PSI 7.7 CFM
Air Delivery SCFM At 90 PSI 6.2 CFM
2 HP
175 PSI max
30 gal
120v

The description of the same compressor at Lowes says it's NOT good for most of the things I want it for, but from what (little) I understand, 6.2 @ 90 PSI would be.

I have a 20 amp breaker for the garage. Can I run a 120v compressor?

 

[KwikFab]

I run a dedicated 20 amp circuit just for my air compressor. Thing is, you can only get so much power out of 110v.

Since you mentioned painting, you're going to really want a 220v air compressor as you'll need plenty of filtration for your air setup.

Any filtering you have between the air compressor and the gun is going to act as an inhibitor.

 

[hellfish]

Painting is a distant maybe, and probably for one job. FWIW, this car was primered and painted with a 20 gal Craftsman in my 110 garage several houses ago. My box is maxed out, so I can't upgrade the garage electrics. An electrician quoted my $5000 to run 220 the 20 feet to my garage because it also involved a breaker box upgrade, new meter, etc. It's a hobby, so I can get away with 110. I don't use a compressor much, but would like one for the tasks I mentioned.

 

[KwikFab]

For everything else mentioned, it'll be fine.

You described the same Dewalt I've got.



Bought it new from Tractor Supply for $500.

 

[driftpin]

You can do anything you need to with that compressor, just not for very long.

Save-up and get something more-suitable for continued use/continuous use, and I bet you will be much-happier w/the time spent working where you need air volume.

 

[GeoBruin]

Yes, you can run that compressor on a 20 amp circuit. The best performance you're going to get from 120 volt compressor is about 7.4 cfm at 90 psi with a Quincy Q1214VPQ or any of the other brand variants (Chicago Pneumatic, Bellaire, Napa, etc). That's currently the practical max in the market.

In my experience, that is enough to do everything you describe, with some limitations as described by others above. If you are aware of those limitations, and comfortable with them, you're good to go. If you have specific questions about specific tools with specific air demands, we can provide more specific feedback.

 

[hellfish]

For everything else mentioned, it'll be fine.

You described the same Dewalt I've got.

Bought it new from Tractor Supply for $500

Same one, same place, but it's now on sale for $599... or $918 at Lowes.

Ideally I would save up and get a bigger, better one, but I'm limited to 120, so that only gets me so far. I've also built several cars without a compressor, so this is more of a want than a need. This one seems like a decent price for a US compressor. I'm not sure I trust the HF variants, but the store brands like Kobalt seem ok.

What specs should I be looking for in terms of SCFM? What's more important, Max PSI or SCFM? I'm borrowing a compressor now that's 200 PSI and 5.4 SCFM and seems ok

 

[KwikFab]

Same one, same place, but it's now on sale for $599... or $918 at Lowes.

Ideally I would save up and get a bigger, better one, but I'm limited to 120, so that only gets me so far. I've also built several cars without a compressor, so this is more of a want than a need. This one seems like a decent price for a US compressor. I'm not sure I trust the HF variants, but the store brands like Kobalt seem ok.

What specs should I be looking for in terms of SCFM? What's more important, Max PSI or SCFM? I'm borrowing a compressor now that's 200 PSI and 5.4 SCFM and seems ok

SCFM at a given air pressure.

I still take these ratings lightly, but they're better than back in the days of "7cfm at 90psi" on this tiny electric Craftsman where ratings were at the pump or whatever and not the actual air being put out for the end user.

The one I've got has been with me for over a year and a half now (November of '23) and I got it during a Black Friday weekend of some sort. Normally it's a $600 compressor like you said.

 

[tak1313]

That's pretty decent specs for a 110/120v IMHO. You will likely have to be intermittent on some things, but I have personally used a similar compressor for awhile (contractor CH rated at 6cfm @ 90 psi) until I got my 240 Husky (made by CH). You just have to patient sometimes and allow it to cycle depending on what tool you're using, but I PERSONALLY feel it's totally doable for DIY purposes. I even poly sprayed full kitchen cabinets with an HVLP conversion sprayer without a problem (other than having to occasionally stop for cycling) - never sprayed a car though. Attached are older pics before the doors were done.

Then I got into battery (Milwaukee) for tools, and turbine HVLP for spray, and haven't touched the compressor for at least 7 years or so.

 

[GeoBruin]

Same one, same place, but it's now on sale for $599... or $918 at Lowes.

Ideally I would save up and get a bigger, better one, but I'm limited to 120, so that only gets me so far. I've also built several cars without a compressor, so this is more of a want than a need. This one seems like a decent price for a US compressor. I'm not sure I trust the HF variants, but the store brands like Kobalt seem ok.

What specs should I be looking for in terms of SCFM? What's more important, Max PSI or SCFM? I'm borrowing a compressor now that's 200 PSI and 5.4 SCFM and seems ok

Quick clarification that the Dewalt is not a "US compressor" in the way that you might think. The tank may have been made in the US, and the whole thing may have been assembled in the US, but the pump and the motor were not made in the US. Not that it matters, but just so you don't think you're getting something different by buying a Dewalt than a similar thing at Harbor Freight.

For most things, higher CFM is going to matter more than higher max pressure. That said, a max pressure that is too low, can cause it's own issues, but 175 PSI is quite comparable to the max pressure for many two stage compressors, so you shouldn't have any problems there. As mentioned above, the most flow you're going to get out of a 120 volt compressor is around 7.4 CFM at 100 psi and that's going to be closer to $1,000 before shipping, so the 6.2 CFM at 90 PSI of the Dewalt you're looking at is a pretty good deal.

Again, if you can tell us the actual air consumption of a tool you're looking to run, it's pretty straightforward to figure out how long you'll be able to run it.

 

[hellfish]

Quick clarification that the Dewalt is not a "US compressor" in the way that you might think. The tank may have been made in the US, and the whole thing may have been assembled in the US, but the pump and the motor were not made in the US. Not that it matters, but just so you don't think you're getting something different by buying a Dewalt than a similar thing at Harbor Freight.

True. What the label actually says is "Made in the USA with global materials" which I take to mean that it was assembled here, but steel and other parts (maybe assembled pump, etc) came from elsewhere. I, at least hope, that is better than something completely manufactured in China, although they may be getting better.

 

[mikedodge]

It's all lies the made in USA label, the listed HP.... I think mine say assembled in USA or North America or something actually...

 

[rust in the eye]

Painting is a distant maybe, and probably for one job. FWIW, this car was primered and painted with a 20 gal Craftsman in my 110 garage several houses ago. My box is maxed out, so I can't upgrade the garage electrics. An electrician quoted my $5000 to run 220 the 20 feet to my garage because it also involved a breaker box upgrade, new meter, etc. It's a hobby, so I can get away with 110. I don't use a compressor much, but would like one for the tasks I mentioned.

Sounds like hoo-ha from here, a sub-panel would cure that.

 

[dnschmidt]

Dream on. We get these questions about twice a month and the answer never changes.

Air tools: Impacts yes, air hammers maybe
Sanders: Not a chance
Spray gun: not a chance in hell unless you're only doing one panel at a time with a mini-gun
Die grinders: FORGET ABOUT IT.
Belt files to grind away plug welds: No way

I have a 5 HP Quincy that puts out 17.5 SCFM and I sure as hell wish it had more output. These small compressors are for nail guns and pumping up tires and basketballs and that's about it.

Yea, I know I'm an old ***** that crushes dreams and that's all true. I also took a lot of Physics classes and Physics doesn't give a **** about what you can afford or what you want to do. Physics is heartless. SATA, Iwata, DeVilbiss and Sagola all need at least 15 SCFM for their guns and unless you're really into cutting and buffing out orange peel that's what they need. They're just as heartless as Physics.

 

[gimpyrobb]

You could always go with a gas powered compressor...

 

[KwikFab]

Dream on. We get these questions about twice a month and the answer never changes.

Air tools: Impacts yes, air hammers maybe
Sanders: Not a chance
Spray gun: not a chance in hell unless you're only doing one panel at a time with a mini-gun
Die grinders: FORGET ABOUT IT.
Belt files to grind away plug welds: No way

I have a 5 HP Quincy that puts out 17.5 SCFM and I sure as hell wish it had more output. These small compressors are for nail guns and pumping up tires and basketballs and that's about it.

Yea, I know I'm an old ***** that crushes dreams and that's all true. I also took a lot of Physics classes and Physics doesn't give a **** about what you can afford or what you want to do. Physics is heartless. SATA, Iwata, DeVilbiss and Sagola all need at least 15 SCFM for their guns and unless you're really into cutting and buffing out orange peel that's what they need. They're just as heartless as Physics.

Dang, I should go return mine then because my die grinders and belt files shouldn't work at all even though I've been running mine for over a year and a half.

 

[Steve_P]

Dang, I should go return mine then because my die grinders and belt files shouldn't work at all even though I've been running mine for over a year and a half.

A Dynafile/belt file uses 20+ CFM when in use. If you use it for 15 seconds and stop for a minute while your compressor catches up, fine, but they're not running on 6 CFM for long. RO/DA sanders all use well over 10 CFM. You can look up real specs for air consumption on the Dynabrade website as they do not assume a 20% duty cycle, or whatever nonsense, like other manufacturers do. Most full size HVLP guns use well over 10 CFM unless something has changed. I won't argue this, so I'll end it here.

Dynabrade Power Tools | Made in USA

Air and electric power tools, abrasives, industrial vacuums, automation, and more for every industry. Learn more about our tool solutions.

www17.dynabrade.com

 

[ohhimark]

I have a compressor about that size (currently running on 220) and it has to catch up a lot when cutting/grinding/porting. I've been kind of waiting for it to burn up so I can upgrade it. I'd honestly look into a sub panel as mentioned above, or replace some of your breakers with ones that combine breakers into the size of one to free up space for a 220.

 

[908Jim]

It's a MAT Industries compressor. Manual even says so. It's a good quality machine sold under a lot of different brands. It's no industrial compressor, but it's better than some screaming oil free unit of yesteryear.

Back at OP, as others have said, you're limited by physics here. 5.7 is about all you're going to get out of a 120v circuit and there isn't much you can do to change that. With that being said, you can always compensate a bit with storage volume. The higher tank pressure of this compressor helps, and an Industrial air 20 gallon 200PSI tank is about $250 give or take. It would nearly double your storage capacity, meaning you could run tools a little longer with the tradeoff being longer time to resume work.

Years before I had access to 240v I had two small tanks plumbed together and longer run time made waiting for tools to catch up more tolerable. Edit: Usually just got coffee or a snack or something.

 

[joe_padavano]

Dream on. We get these questions about twice a month and the answer never changes.

Air tools: Impacts yes, air hammers maybe
Sanders: Not a chance
Spray gun: not a chance in hell unless you're only doing one panel at a time with a mini-gun
Die grinders: FORGET ABOUT IT.
Belt files to grind away plug welds: No way

I have a 5 HP Quincy that puts out 17.5 SCFM and I sure as hell wish it had more output. These small compressors are for nail guns and pumping up tires and basketballs and that's about it.

Yea, I know I'm an old ***** that crushes dreams and that's all true. I also took a lot of Physics classes and Physics doesn't give a **** about what you can afford or what you want to do. Physics is heartless. SATA, Iwata, DeVilbiss and Sagola all need at least 15 SCFM for their guns and unless you're really into cutting and buffing out orange peel that's what they need. They're just as heartless as Physics.

^^^THIS! I struggled with too-small compressors for years. About 10 years ago I finally assembled a frankenpressor with a Rol-Air K30 pump (23.5 SCFM) and a 7.5 HP single phase Baldor. Wow, what a difference. Media blasting is almost pleasant now (well, except for that grit where it don't belong thing). It doesn't even breathe hard with the highest-use air tools I have. By the way, I have less than $1000 into that compressor (used tank, used pump, brand new Baldor and other small parts). Yes, I had to run a 50A circuit for the compressor. Of course, now I want 30 SCFM.