Air Compressors for sandblasting

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

So I'm learning that there is no such thing as an air compressor that plugs into a 120v outlet that will make enough CFM for sandblasting. Huge tank, small tank, doesn't matter once the pump kicks on. Belt drive is quieter than direct drive but both flow about the same, 6-7 SCFM at 90 psi. 30 year old compressors and brand new ones are surprisingly similar (for belt drive at least), the technology hansn't changed much.

It's all limited to the power available on a 120v circuit. Even the most expensive 60-gal $1000 fancy-brand compressors really offer no additional pump flow.

So I'm wondering what others have bought or done for high-flow applications. Realistically I don't need or want a big tank -- 20 gal would do -- but I can't find a 240V compressor with a small tank. 99% of the time I don't need the flow rate, but I would really like big motor(s) for the occasional blasting project. I know, I can just wait for the compressor to catch up, but I'm impatient

Right now I have experimentally staged two 120v compressors together, with one old 20gal 6.3 SCFM belt-drive kicking on at 85-110psi and one newer 12gal 6.9 SCFM direct-drive kicking in at 80-105psi. So far this looks like it might work for getting 13+ SCFM but DAMN is is loud when both compressors are on.

Anyone been through this before? Recommendations for smaller-tank 12+ SCFM@90psi units? Or successful dual-compressor staging setups?

Scott Johnson · **Posted:** Tue Apr 22, 2008 12:32 pm

I have an Ingersoll Rand 2430 2 stage unit (230V). You are welcome to bring some sand over and try it out, or if you are really generous with the beer you could borrow it for the weekend (it weighs 400 lbs, so be prepared - I do have a wooden sled that it can be loaded on to).

I inherited it from my late uncle (my aunt was asking half price).

I've never done anything that the compressor can't handle, blasting, cutting, painting, die-grinding. Nothing. It will kick on and run continuously while blasting, but it keeps up just fine. I can change a set of tires and air them all up without even cycling the compressor.

It's this one:

The big belt drive units are also pretty quiet. If I mounted mine on rubber pads and made an intake muffler it would be even quieter.

Scott

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Just found this one which would be near perfect for me. Small tank (I don't care about long trigger time before the motor kicks in) with a big honking compressor and motor. 3HP motor delivers 13.8 CFM @ 100 PSI. Too bad it's $1400:

http://www.amazon.com/D55395-Heavy-Duty ... B0008KL79K

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Getting closer. Finally found a "cheaper" one that can still fit under my workbench with NICE specifications. 3HP, 10.3 SCFM at 90psi. Still $500.

http://www.cpocampbellhausfeld.com/air_ ... t6271.html

Donnie Barnes · **Posted:** Tue Apr 22, 2008 8:12 pm

I know there is a huge price difference, but that CH unit seems a good bit more sketch on actually meeting the numbers to me. Looks single stage versus the two stage on the DeWalt.

What do the little pancake and twin tank compressors do that are made for contractors? Not enough CFM? Seems like air nailers eat some air...

--Donnie

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Donnie Barnes wrote:

What do the little pancake and twin tank compressors do that are made for contractors? Not enough CFM? Seems like air nailers eat some air...

Pancakes and twin tanks are just like all the other 115v units -- 5-6 SCFM at 90 psi. Air nailers aren't very air-hungry, relatively speaking. If one was shooting nails machine-gun style, then yeah, but that pause of a second or so between blasts really relieves the requirement.

It's generally said that air sanding and sand blasting need 12-15+ SCFM at 90 psi to do the job.

Also, regarding single/dual stage, I'm finding dual stage is pretty rare in units under $1000. Most of the belt-drive units seen with a two-piston arrangement are just two pistons doing single stage. The CH compressor is nothing special compared to the myriad 2HP 115v belt drive units out there EXCEPT that it uses a 3HP 230v motor. The compressor is probably sized up to handle the higher RPMs.

Richard Casto · **Posted:** Tue Apr 22, 2008 9:35 pm

Mike,

What is the objection with the larger tank? I know you are talking CFM, but with the larger tank if you are blasting with a lower pressure you will cycle the compressor less often (less noise) and most of the larger tanks are not going to have a much larger footprint than a smaller tank. Granted they are taller.

I am using a Lowes "Kobalt" 60 gallon 220v unit. I swear that you can get the exact same unit at HF. Other than the HF is in black and the Lowes unit is blue, I challenge you to find a difference right down to the manufacture of the electric motor. HF seems to have remanufactured units for what looks to be great deals periodically.

Of course I can't find either model on the HF or Lowes website right now.

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Richard Casto wrote:

Mike,

What is the objection with the larger tank? I know you are talking CFM, but with the larger tank if you are blasting with a lower pressure you will cycle the compressor less often (less noise) and most of the larger tanks are not going to have a much larger footprint than a smaller tank. Granted they are taller.

Good question and great observation on the low-pressure use. My allocated compressor space is a nice spot under my workbench

Hence my desire for a horizontal unit. I also plan to add some sound-deadening under there, it's a perfect spot.

Mainly though, I don't want a big huge tank in my garage. Realistically it's overkill. I never "need" that much quiet trigger time. Just need the rare high-flow-rate that the motor provides. So the big tank is just overkill, looking for something "right sized".

Now if I ran air tools every day I would be looking at a big one. But for sandblasting 10 times a year I'm trying to keep my floorspace in the garage at a maximum.

steve remchak · **Posted:** Tue Apr 22, 2008 10:07 pm

Richard Casto wrote:

Mike,

What is the objection with the larger tank? I know you are talking CFM, but with the larger tank if you are blasting with a lower pressure you will cycle the compressor less often (less noise) and most of the larger tanks are not going to have a much larger footprint than a smaller tank. Granted they are taller.

I am using a Lowes "Kobalt" 60 gallon 220v unit. I swear that you can get the exact same unit at HF. Other than the HF is in black and the Lowes unit is blue, I challenge you to find a difference right down to the manufacture of the electric motor. HF seems to have remanufactured units for what looks to be great deals periodically.

Of course I can't find either model on the HF or Lowes website right now.

if the Lowes website is any indication Richard, Kobalt is out of the compressor business. i have the 30 gallon, but it only pushes 5.5 or so @ 90psi.

Donnie Barnes · **Posted:** Wed Apr 23, 2008 10:33 am

Mike, why the requirement for it to be inside? I've gotten to where I hate compressor noise, so the further away I can get it, the better. Just note that if you do mount one on a pad outside that you need to use a piece of flexible hose in your plumbing to the building so that vibration doesn't break your pipe. We also bought some big poly bushings from an auto parts store to set it on and bolt through to the concrete, which helps deaden sound a lot.

I know, you're going to go inside. I just through that in for folks finding this thread later. Scott already mentioned the bushing thing, but I thought I'd add it, too.

My two stage IR compressor once ran for several days solid due to a busted line in the shop (over a holiday) and never seemed worse for wear.

--Donnie

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Donnie Barnes wrote:

Mike, why the requirement for it to be inside?

My neighbor's master bedroom is close to my garage, so I'm trying to minimize noise outside. Although I'm helping him prep his M3 for track use, so he should just shut up and put up with it

BretLuter · **Posted:** Mon Apr 28, 2008 9:16 pm

OK, so what did you buy?

(I saw the 2 smaller compressors you have in the FS section........)

Bernie Baake · **Posted:** Mon Apr 28, 2008 10:42 pm

Why don't you feed the two compressors into a common manifold and use the output of the manifold when sand blasting. Use the smaller one for all other low flow requirements???

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Bernie Baake wrote:

Why don't you feed the two compressors into a common manifold and use the output of the manifold when sand blasting. Use the smaller one for all other low flow requirements???

I did that for a while but decided I didn't want the extra complication of hoses, floor space, pressure valve setting, and tank drains. Plus it gets damn loud when both compressors kicked in.

BretLuter wrote:

OK, so what did you buy?

Richard and Scott talked me into a big one ... they are cheap at big-box home stores, and I got a good discount on a better-than-it-should-be model -- bought a the Husky 60 gal upright for $399-$60 off special promo at HD.

The tag was for the 3000hr, louder, "VH6314" with a v-twin compressor, but what they had stocked was the VT6314, an inline-twin (made by Campbell Hausfeld) which sells online for $500+, and very similar to the VT6275. Comes with a 4-year warranty and the compressor is rated for 5000 hrs. Should last me a while

230v, 15 amp, 10.3 SCFM@90 psi. Still not enough for continuous duty sandblasting but much better than I have been using.

Sean O'Connell · **Posted:** Tue Apr 29, 2008 9:48 am

So mike what is the limiting factor, the motor or the compressor? If it is the compressor I could see the need to upgrade the entire unit, but if it is the motor why couldn’t you just buy a bigger more powerful motor and attach it to the old compressor and tank? I know if haven’t done the research you have so maybe you know something I don’t.

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Air Compressors for sandblasting

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