Who should I look at for a 15 CFM plus compressor?

[69daytona4me]

I am looking to start doing some rim refinishing in my home shop. My 20 year old compressor compressor will not keep up with the work I will need to do in the blast cabinet as it was only 10 CFM @ 90 psi new. I'm looking to get a compressor that is at least 15 CFM or more at a fair price. I have to admit, I don't even really know what to look for in compressors as I have never shopped for a "real" one that puts out a lot of air. Any constructive input would be appreciated. I'd also appreciate any links to 4th of July specials on really good/15 psi or better units.

 

[NOZZLEMAN]

I've had an Ingersoll-Rand consumer grade I got at Tractor Supply and it is going on 3 1/2 years now, with one motor change and the compressor unit has leaked oil since day one. Just got a Quincy from Northern Tool and it is EXCELLENT !! We use it commercially in the shop & have a blast cabinet & keeps up great. worth the extra $$ Good Luck !!

 

[md21722]

It takes about a 5 HP air compressor which will make about 17-18 CFM. Prices are across the board from $700 for a big box store one to $2,900 for your fully packaged Saylor Beall or Champion. In between there are the FS Curtis CT Series which for around $1,750 and the Quincy QT go for about $2000. I would look for one with an after cooler option since it will help eliminate water in the lines. The low oil safety on the pump and automatic tank drain are nice features, but you can save about $300 if you check your oil level & manually drain the tank. If the compressor is used in a dirty, dusty environment (i.e. grinding, sanding without vacuum equipment) look for one with a TEFC motor. Most motors are ODP which means they are cooled by sucking air through the windings. TEFC motors are "totally enclosed" and blow air around the motor. A TEFC will last longer in dirty and dusty conditions. This is a $100 add on on the better compressors.

My local compressor dealer likes to sell the FS Curtis CT series because they are competitively priced so they make some money and the customer is happy. They say most of the tire shops in town are using them now and they really don't have any problems. The 5 HP is about $1,750 and the 7.5 HP is about $2,300.

I am partial to Champion myself.

The cheapest thing you can do is buy another Home Depot Husky 3 HP and run both together which would give you about 20 CFM.

It all depends on what your budget is and what you really want.

Consider calling your local compressor dealers if your budget is over $1,500. You may be surprised at what they have.

Also consider going bigger than you "need" so the compressor cycles on and off. The compressors you'll be looking at generally have a 80/20 duty cycle. They are not meant to run 24x7x365.

 

[69daytona4me]

Great info! Thanks very much guys.

 

[bob15]

Look on Craigslist.

I bought an IR T-30 model 252 (20+ cfm) for three hundred. The catch is I needed to buy a new motor and pressure switch because it was 3 phase. With a total of $700 spent (compressor & motor), I now have 2.5-3k dollar compressor.

 

[jptbay]

I've had this 18.5 CFM 60 gallon unit for almost 15 years now. Sand blasting, painting, 3/4 drive air tools, all no problem. Been rock solid. Nice quiet unit. Fairly low RPM. Cast iron cylinders.

http://www.eaglecompressor.com/shop/single-stage/c5160v1/

 

[jptbay]

Code STARS16 gets you 15% off at CPO outlet.

For $849 plus freight you could get this: http://www.cpooutlets.com/industrial-air-ila5746080-5-7-hp-60-gallon-oil-lubricated-stationary-air-compressor/idanila5746080,default,pd.html

 

[MacMcMacmac]

I'd second the idea of checking out some local compressor shops. We used to have some really nice rebuilt stuff in the shop that no one would buy because it was "only 3hp" when they would have been getting a pressure lube Quincy for the price of a Harbor Freight/Princess Auto unit that made the same amount of air.

 

[PSYKO_Inc]

Was your compressor able to keep up at one point, but seems less effective now? Could be as simple as new gaskets and reed valves. I always try to fix something before replacing it outright.

 

[DSLTRK]

Great info! Thanks very much guys.

Your best bet is to look for a used quality unit. With proper maintenance, these compressors rarely break down.

Quincy, Champion, older IR are all good units that have repair parts readily available.

You don't need pressure lubed, but it is nice to have if you can find one with it. I've seen splashed lubed Champion pumps with tens of thousands of hours on them on their original parts and lasting through several motors. So I don't see a difference in lasting longer?

If you must buy new, the best value is going to be a Quincy Qt-5 or Champion VR5-8. Although a little bit more, the Champion has a superior pump that is equipped with disc valves vs reeds for the Quincy, the bearings are also tapered roller vs ball.

Good luck, both will serve you well

(Avoid newer IR like the plague.)

 

[CompressorPros.com]

15 CFM is a sweet spot for lower cost two stage air compressors. The BelAire 216V and the Chicago Pneumatic RCP-561VNS continue to be two of our top sellers. Both are built by Atlas Copco on the same assembly line, just paint and decals make them different. You can't beat the warranty...2 Years on everything. Most manufacturers do not cover valves past one year as they consider them wear parts, but even belts are covered on these for the whole two years.

BelAire 216V

CP RCP-561VNS

 

[BK13]

15 CFM is a sweet spot for lower cost two stage air compressors. The BelAire 216V and the Chicago Pneumatic RCP-561VNS continue to be two of our top sellers. Both are built by Atlas Copco on the same assembly line, just paint and decals make them different. You can't beat the warranty...2 Years on everything. Most manufacturers do not cover valves past one year as they consider them wear parts, but even belts are covered on these for the whole two years.

BelAire 216V

CP RCP-561VNS

Do you gain much if you go from a 60 gallon tank to an 80 gallon tank, given the same pump, or is it just added cost and bulk? (Given that usage would probably be impact wrench, ratchet, air hammer, die and angle grinder, and DA sander, maybe sand blast cabinet in the future)


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[motofool33]

the bigger question is what are you blasting?, how long are you trying to blast at one time, and what size nozzle are you using?>

i thought 5hp was enough to keep up with my blast cabinet it really did not even with smallest nozzle available. so i moved upto a 7.5hp 120gallon tank

 

[xbeatles4x]

Man. This thread is eye opening. I was planning to get a compressor to power a sand blaster for my project car to clear up some rust. Maybe even get a cheap paint sprayer to lay some primer too. Now this is making me second guess my thought process. I thought I could get away with a 5 or 7 hp compressor and maybe a 60 gallon tank. My use is strictly for hobby though.

 

[motofool33]

Man. This thread is eye opening. I was planning to get a compressor to power a sand blaster for my project car to clear up some rust. Maybe even get a cheap paint sprayer to lay some primer too. Now this is making me second guess my thought process. I thought I could get away with a 5 or 7 hp compressor and maybe a 60 gallon tank. My use is strictly for hobby though.

if your not trying to blast the whole car you'll be fine you will just have to wait for the compressor to catch up. my 5hp 60gallon T-30 did fine on painting. but lots of blasting it could not keep up without having to stop.

 

[CompressorPros.com]

Do you gain much if you go from a 60 gallon tank to an 80 gallon tank, given the same pump, or is it just added cost and bulk? (Given that usage would probably be impact wrench, ratchet, air hammer, die and angle grinder, and DA sander, maybe sand blast cabinet in the future)


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If it were me, I wouldn't spend the extra just for 20 gallons of air storage. The compressor makes the same amount of air regardless of tank size, so I would go with the 60 gallon.

These units could handle 1/2" impacts with not problems. Sanding and sand blasting can take a lot of air, so you would just need to be make sure it is not running constantly.

 

[DSLTRK]

Man. This thread is eye opening. I was planning to get a compressor to power a sand blaster for my project car to clear up some rust. Maybe even get a cheap paint sprayer to lay some primer too. Now this is making me second guess my thought process. I thought I could get away with a 5 or 7 hp compressor and maybe a 60 gallon tank. My use is strictly for hobby though.

A bigger tank helps with less frequent stop/starts of the pump. That will lengthen the life of the motor.

The pump will run longer between cycles though.

 

[CompressorPros.com]

I put together a generic sizing guide. There will always be exceptions, but this might help some...

Sizing Guide

 

[xbeatles4x]

if your not trying to blast the whole car you'll be fine you will just have to wait for the compressor to catch up. my 5hp 60gallon T-30 did fine on painting. but lots of blasting it could not keep up without having to stop.

Eventually I plan to blast the whole car but at the rate I am working I will be blasting the pieces I am working on at a time. I figured blast a not so great area, access the area, weld in new metal. Use the same compressor to primer over the area and wait until the next weekend to work on the next area.

From what I gather I will need 15 cfm capacity for the sand blaster.

 

[BK13]

If it were me, I wouldn't spend the extra just for 20 gallons of air storage. The compressor makes the same amount of air regardless of tank size, so I would go with the 60 gallon.

These units could handle 1/2" impacts with not problems. Sanding and sand blasting can take a lot of air, so you would just need to be make sure it is not running constantly.

Thank you!

 

[md21722]

Do you gain much if you go from a 60 gallon tank to an 80 gallon tank, given the same pump, or is it just added cost and bulk? (Given that usage would probably be impact wrench, ratchet, air hammer, die and angle grinder, and DA sander, maybe sand blast cabinet in the future)


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When going vertical, 80 gallon is about the minimum for the industrial air compressors because the extra bulk helps with stability when you're putting 250-500 pounds on the top plate. On the smaller, lighter compressors like the OP's 3HP Husky it isn't as important. The motor and pump weigh 70 pounds combined.

Part of sizing the air tank is how the compressor will cycle given normal workloads. When blasting the compressor is probably going to be running constantly, so tank is not a big deal. I would get the after cooler option. With out the after cooler, that tank is going to get hot pretty quick and you are going to be dealing with water.

Most folks who paint or blast end up getting an after cooler, a wall of copper to serve as a radiator, air dryer, multiple tanks in series, or other means to keep the air cooler and remove the water before it gets to the blasting and paint nozzles.

 

[CGT80]

I recently upgraded from a 3hp 60 gallon single stage 135 psi 10 cfm to an old pressure lubed cast iron LeRoi Dresser 5hp 80 gallon two stage 175+ psi.

80 gallons is much nicer than 60 and having to pressure switch set for 150 psi vs. 135 on the old compressor means I have a ton of air stored. I can run a die grinder for 5 minutes or more without the compressor turning on. It takes 60 seconds to fill from 115 psi to 150 psi, and 5.5 minutes from 0-150. It is rated at 17.2cfm @175psi, but an online calculator shows 20 cfm average for the fill. Also, I installed a bigger pulley to set it at the proper speed for a 5hp motor, and it could be a few rpm higher than the 800rpm target. This thing is very quiet compared to the average 3hp aluminum oil lube compressor that home depot or sears would sell. I can stand next to it and talk by just slightly raising my voice (it is outside) and at 50 feet away you hear it, but it is a nice chugging sound that blends in with other city noises. Even right next to it, the noise is there, but it isn't harsh or annoying. Just the sound, even from 75' away, of the old cheap compressors was nerve racking.

At 100 psi at the blast cabinet, it will catch up and shut off for a few minutes. This is a HF cabinet that I rebuilt and installed a skat blast gun into, but I don't remember the size of the nozzle. It is small and it can take a while to blast heavy rust or large parts with medium grit glass bead.

TLDR: 17-20 cfm seems great for a small cabinet and running die grinders. 80 gallons is absolutely worth having if you have the space and want to run tools without cycling the compressor all the time, but 60 would work (I wouldn't go back to a 60). At first I was worried this compressor would not be big enough (it was only running at 600 rpm, 3/4 speed, when I got it), but at full output it is impressive. Big, cast iron compressors can be very quiet and they run much cooler than a small 10 cfm aluminum unit.

PS: there is no way I would think of blasting a whole car with less than 100 cfm. 200cfm would be much better and a 1/2" nozzle and a couple hundred pound capacity pressure pot. My uncle's father blasted the inner bed and tailgate (and the hood at a different time) of my truck with 220 grit aluminum oxide. They blast power plant turbines for a living and have big equipment. He knew how to not warp the panels and it turned out fine for a daily driver. I would do all the repairs on the car and then have it blasted by someone who does cars all the time, or better yet, have the car and parts blasted before you repair them so you have clean metal to work with. My family also has large blast cabinets and they run a 20 or 25HP 75 cfm LeRoi dresser compressor to run those in the shop. 5hp is very small. With a small machine it will be many hours of wear and tear on the machines and user plus lots of electricity, but I am sure it is possible if you are up to it.

 

[CGT80]

Most folks who paint or blast end up getting an after cooler, a wall of copper to serve as a radiator, air dryer, multiple tanks in series, or other means to keep the air cooler and remove the water before it gets to the blasting and paint nozzles.

I agree, but will share a method used for large scale blasting.


Run the compressor balls to the wall so that the air is so hot that water never condenses. My family runs diesel compressors that are 175-250 cfm. They try to use the smallest compressor and run it wide open. It might be hard on equipment, but it seems to work for them. They blast at a power plant in Arizona where it is 120+ degrees outside in the summer and the blast hose stays much hotter. It burns their skin a bit through gloves and clothing, but water isn't a problem. They offered to let me work with them, but that isn't my cup of tea. The blasting they do at the shop (mostly outside in the open) would have been fun, but I only blasted an office chair that I restored and they have blasted the other projects I have taken in. For these small projects, humidity hasn't been a problem and they don't always run the compressors at full power, but the climate is pretty dry and that type of compressor is different from the piston units we use in our shops, on the forum.

 

[md21722]

I recently upgraded from a 3hp 60 gallon single stage 135 psi 10 cfm to an old pressure lubed cast iron LeRoi Dresser 5hp 80 gallon two stage 175+ psi.

80 gallons is much nicer than 60 and having to pressure switch set for 150 psi vs. 135 on the old compressor means I have a ton of air stored.

Upgrading from a single stage to dual stage solves a lot of issues. The higher pressure gives you a lot more breathing room. As an example, my dual stage cut in at 130-135 and cut off at 170-175. The eliminates all the issues I had with pressure drop with single stage compressors. Also, dual stage compressors don't "slow down" as pressure increases. In other words, using a dual stage it will take the same amount of time to pump from 80-100 as it will from 150-170. On the other hand, single stage compressors often drop off after 105-110 psi. So a single stage rated at 10.3 CFM @ 90 PSI may only pump at 6.5 CFM @ 120.

I'm not sure there's a great difference between a 60 and 80 gallon dual stage tank. Most of the difference seems to come from the higher pressure which results in more storage anyway.

I will say that I have 2 x 60 gallon Champion 5 HP and a 3rd 60 gallon tank as extra storage and do really notice the 60 gallon extra. Yes, they do run longer when they run to fill that extra 60 gallons of tank, but I can go longer between cycling using impacts, ratchets, drills, and die grinders. Angle grinders are single biggest user of air that I have. They are rated at 35 CFM @ 90 PSI free speed. With a wheel on and in use, they use about 20% less so my compressors can both supply working pressure and build up tank pressure when they cycle on.

For the other poster that talked about huge diesel compressors, that is what some people do when they are blasting. These are typically powered by stationary Cummins 6BT engines (same as in old Dodge trucks, back hoes, ...) and can produce anywhere up to 400 CFM.

Personally I think the OP will be happy with a 7.5 HP or even a 10 HP single phase air compressor. The 5 HP is somewhat marginal for blasting if you only have one of them.

 

[xbeatles4x]

Sorry for kind of taking over this topic but my question is a bit similar. My use would be sanding a few spots here and there on my VW and I am still looking at the compressors that you guys recommend. Even second hand they put me in the $700-1000 area. Is there a possibility that for light duty sand blasting and waiting more for a tank to fill up I could get by with a less expensive tank?

Maybe something like this?
http://miami.craigslist.org/mdc/tls/5615941381.html

and this

http://www.harborfreight.com/1-liter-abrasive-blast-gun-92857.html

I am still trying to learn what I can on this topic but I didn't want to fork over much more if I can get by with that.

Other than sand blasting there is a possibility that I would use the same tank for light priming of the spots that I sand after addressing some body work and possibly also using a pneumatic palm sander for the same areas. This is purely a hobby for me.

 

[md21722]

DA's usually use 15-17 CFM. If you want to use air you need to open your pockets. A 3 HP single stage ain't going to cut it. If you're patient let us know how it works out for you!

 

[xbeatles4x]

Was this any better? Single phase but it is a 7.5hp motor. The only downside is I think it is an oil free motor.
https://offerupnow.com/item/detail/101586995/craftsman-air-compressor-7-hp-175-psi

 

[motofool33]

Was this any better? Single phase but it is a 7.5hp motor. The only downside is I think it is an oil free motor.
https://offerupnow.com/item/detail/101586995/craftsman-air-compressor-7-hp-175-psi

that is a 7.5hp peak compressor not the same as one that is 7.5hp all the time.

a true 7.5hp would be like a 15hp peak

 

[xbeatles4x]

Just so that I know. Would this be the type of compressor I would need then? Price is a bit beyond what I wanted to stay at and I doubt they would budge to where I wanted to pay but I wanted to know if this is more or less what I should be looking for.

http://miami.craigslist.org/brw/tls/5660484049.html

 

[Xicaque]

Look at Quincy QT 7.5. Top notch for a hobby driven need. I am very pleased.


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[motofool33]

Just so that I know. Would this be the type of compressor I would need then? Price is a bit beyond what I wanted to stay at and I doubt they would budge to where I wanted to pay but I wanted to know if this is more or less what I should be looking for.

http://miami.craigslist.org/brw/tls/5660484049.html

that would be the perfect compressor for you for 700 new that would be a 2599$ compressor on compressors direct site.

 

[Rossco]

Ah. Meh.

Ide recommend a 'Devilbiss - Devair - DV Systems' 247 - 80gal with a 5hp Baldor.

Can be had for very reasonable $$$ used and weighs 690lb. 7 year warranty on a new'un.

 

[md21722]

Just so that I know. Would this be the type of compressor I would need then? Price is a bit beyond what I wanted to stay at and I doubt they would budge to where I wanted to pay but I wanted to know if this is more or less what I should be looking for.

http://miami.craigslist.org/brw/tls/5660484049.html

This one is more dirty than the ones I see around our area. When clean they start listing them at $1300 - 2000 used and the ads drop off. Make sure there is an air filter in there and it will probably be a decent compressor for you. If the motor ever fails, look to eBay for a new one before you freak out. Use #6 Romex or #8 THHN when you wire it up. Upsize if it's more than 50 feet from the panel.

 

[xbeatles4x]

Ugh. The guy said $600 would take it. Now I'm really tempted. Let me see if I can scrape the funds for that since I wasn't planning on needing one that big or expensive.

 

[xbeatles4x]

Assuming I were to be more interested in that compressor and wanted to transport it home, how would I do that? The guy claims if you drain the oil out it can be stored on its side. Is that actually the case or ill advised? Realistically what does it weigh?

I'm thinking I'll need to rent a uhaul.

 

[md21722]

It weighs about 600 pounds. No joke. This isn't a 3HP Home Depot special that weighs 260.

Yes you can drain the oil and lay it on its side. Or you can stand it up and use a bunch of strong ratchet straps (preferred).

 

[xbeatles4x]

Damn. That is one heavy sob. I would have to bring a floor jack and maybe my furniture dolly.

 

[xbeatles4x]

I was doing some googling from what I can find and assuming this is the same one, it says it requires 3 phase power ( not for residential homes). I am ignorant on that front too but I do know in our garage we have a 230 volt power. Am I looking at the right unit?
http://www.homedepot.com/p/Ingersol...t-3-Phase-Air-Compressor-2475N7-5-V/203751642

How would I tell? It looks like this one is single phase.
http://www.aircompressorsdirect.com/Ingersoll-Rand-2475N7.5-Air-Compressor/p707.html

Both seem the same to me.

 

[DSLTRK]

I was doing some googling from what I can find and assuming this is the same one, it says it requires 3 phase power ( not for residential homes). I am ignorant on that front too but I do know in our garage we have a 230 volt power. Am I looking at the right unit?
http://www.homedepot.com/p/Ingersol...t-3-Phase-Air-Compressor-2475N7-5-V/203751642

How would I tell? It looks like this one is single phase.
http://www.aircompressorsdirect.com/Ingersoll-Rand-2475N7.5-Air-Compressor/p707.html

Both seem the same to me.

3 phase comes in 120/208 or 230/480. The first voltage listed is a single leg to ground voltage.

Split phase (which you have, commonly called "240v") is what you need. 230 volt is the sum of two voltages. Most compressors are identified using a 1 phase or 3 phase rating. (1ph or 3ph)

your second link you listed is the proper unit.

 

[xbeatles4x]

Is there any way to determine from the photo in the ad that it is indeed single phase?