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[bigwig]

I need an air compressor for a new sandblasting station for my dad's shop.  Given the work we plan on doing, we're told that 5hp 60 gal should be sufficient for the most part.  Of course, bigger is always better.  I want something reliable that doesn't suck.  Budget is $500-1000, but I'd really like to keep it under $800.

Any first hand experience would be great.  I know Lowes, HD, Sears, Harbor Freight, Grainger, ect ect all have units that will fit the bill.  I'm looking for the best bang for the buck.  Craigslist is an option, but honestly, I'd prefer to buy new.  I'm buying my other sandblasting cabinet and blaster from HF most likely, so if I could pick up a compressor from any of the above places, I can do it all in one trip and save some truck rental costs as they are all within 10 miles of each other.

[turbob16hatch]

I have a 60 gal. ingersol rand 22v single stage compressor, I wish i had enough money at the time for a dual stage compressor but mine works pretty good for what it cost, just under $700.

If you have the chance and space for it look for a big ass old compressor, the bigger the better, so get as big as you can. Also dual stage over single hands down. If it is dual then tank size is less important.

[chris]

My hf compressors amazingly hold air perfect but they suck for running for bead blasting throttle bodies,manifolds.



I wouldnt get smaller than 60 unless you want to spend half your life listening to compressors running.

[onlyflash944]

dual stage is the way to go for something that is going to see any kind of volume demand.

[onlyflash944]

personally, ive wanted to get the hf air compressor motor/pump setup and go steal a large propane tankj and build my own for cheap. 

[bigwig]

Chris, What HF unit do you have?

I'd love a dual stage unit, but I have my doubts I'll be able to get a dual stage 60-80 gal unit for $500-1000 unless I get lucky with a used unit.  I will hunt on CL, but no matter what I'll have to rent a truck to pick up the unit.  That's going to be another $100 between gas and rental fees, so I have to figure that into the price.

If I buy new from any of the stores I listed below, I can do the whole pickup in one trip.  I also don't really want a 30-40gal unit with dual stage because I don't think I could stand to listen to the compressor all day.  I might be able to remote the unit to a degree, but I think power will become an issue.  I really don't want to pay an electrician $600 to run 150ft of line on a 220V line.  So I think a 60 gal unit will do me just fine.  Luckily, a lot of the blasting will be done at lower pressure on glass and crystal, but we will be doing some blasting on granite and other stones.

[ADSR]

you need high CFM for a pressure pot type. I have a 3cyl eagle that puts out 18 1/2 CFM at 100 PSI. 

[chris]

I have 2 21 gallon cheapo hf units. I bought one like 5 years ago and bought another one maybe a year ago just for bead blasting throttle bodies etc. One of them is used for the shop side motors etc. The other is setup just for the blast cabinet.



The 21 gallon unit just isnt enough for blast work for anything large. Throttle bodies or anything of that nature is fine since its so small but if your planning on doing wheels etc I would spend as much as you can on the biggest setup you can afford


Time is money.

[turbob16hatch]

Nice thing about the non-oil less compressors is how much quiter they run. I had a 25 gal oil less for years, and it was the noisiest POS ever, never will i own one of those again.

[nock]

this is my $250 craigslist pile, i got the tank and motor for free and paid $200 for the pump and ~$50 for a new pulley. anyway, its run like a top for three years and because its a slow running 4 cylinder single stage pump its the quietest compressor ive ever used. big slow pumps last last forever, and the timer drain keeps things dry.

the hf gun is kinda a piece of shit but it seems ok if you drill out the air nozzle inside as much as your air compressor will allow. i think you would be better off with a different gun if your going to be using it all the time.

[stealthiskey]

I also don't really want a 30-40gal unit with dual stage because I don't think I could stand to listen to the compressor all day. 

some truth to that, but 20 gal difference will blow through pretty quick, and take a while to recharge.  basically the compressor will be running all day either way, best invest in a good set of ear muffs, or remote locate.

[Corey]

grab a 20% off HF coupon and grab a 60 gallon HF unit.

i just checked and i cant believe how inflated the prices of compressors have become. home depot has an 80 gallon two stage for 1069 it was 869 a few years ago.

[t_cel_t]

grab a 20% off HF coupon and grab a 60 gallon HF unit.

i just checked and i cant believe how inflated the prices of compressors have become. home depot has an 80 gallon two stage for 1069 it was 869 a few years ago.

its called obama

[bigwig]

grab a 20% off HF coupon and grab a 60 gallon HF unit.

i just checked and i cant believe how inflated the prices of compressors have become. home depot has an 80 gallon two stage for 1069 it was 869 a few years ago.

You can use those 20% coupons at HD and Lowes as well as both should take competitors coupons.  Some will argue that HF isn't on their list, but it is.  I've read a lot of good things about the Kobalt 60 gal.  It was only 300 a few years ago.  If only I had a time machine.

[patsmx5]

grab a 20% off HF coupon and grab a 60 gallon HF unit.

i just checked and i cant believe how inflated the prices of compressors have become. home depot has an 80 gallon two stage for 1069 it was 869 a few years ago.

You can use those 20% coupons at HD and Lowes as well as both should take competitors coupons.  Some will argue that HF isn't on their list, but it is.  I've read a lot of good things about the Kobalt 60 gal.  It was only 300 a few years ago.  If only I had a time machine.

I has a kobalt 60, it's great. Got it for free too.

[malichite]

grab a 20% off HF coupon and grab a 60 gallon HF unit.

i just checked and i cant believe how inflated the prices of compressors have become. home depot has an 80 gallon two stage for 1069 it was 869 a few years ago.

You can use those 20% coupons at HD and Lowes as well as both should take competitors coupons.  Some will argue that HF isn't on their list, but it is.  I've read a lot of good things about the Kobalt 60 gal.  It was only 300 a few years ago.  If only I had a time machine.

I has a kobalt 60, it's great. Got it for free too.

Same one I got, picked it up for $340 last year.  Thing is great.  Has the same motor as the 2 stage 80 gallon.  I may end up switching the pump out later on it for a two stage but for now it is great.

[snm95ls]

this is my $250 craigslist pile, i got the tank and motor for free and paid $200 for the pump and ~$50 for a new pulley. anyway, its run like a top for three years and because its a slow running 4 cylinder single stage pump its the quietest compressor ive ever used. big slow pumps last last forever, and the timer drain keeps things dry.

the hf gun is kinda a piece of shit but it seems ok if you drill out the air nozzle inside as much as your air compressor will allow. i think you would be better off with a different gun if your going to be using it all the time.

Very cool.

I would love to change the pump on the one we have here at the house.

I had an old C-H single stage 2 cylinder that was insanely loud.  We had it in the baesment at the old house, and it would shake the floor above it.

[nock]

i can hardly hear it running in the house, just get a big ass pump and run it slow.

[HiProfile]

I want to hook a big elec motor to a d16 engine/trans. Welded diff & partial CV joint for motor, unfiled rings for max pressure, fill most the combustion chaimbers with jb weld for 15:1 cr, then make a cheap log that outputs to a big one-way valve and then into the compressor setup. Adjust the exhaust valves so there's no overlap, very near 100% possitive displacement.

Locked in 5th on a DX cable trans would net you 27cfm with a 3000rpm elec motor. Or for real ballers, have a d15 with a cheap carb setup connected to that instead, and crank it to 5 grand.


Yeah, just a dream. I actually have an oil-filled compressor head lined up, I plan on adding that in parallel to another compressor to double the cfm.

[buk9tp]

Hook n/a mike's wife up to an air tank.

[snm95ls]

I want to hook a big elec motor to a d16 engine/trans. Welded diff & partial CV joint for motor, unfiled rings for max pressure, fill most the combustion chaimbers with jb weld for 15:1 cr, then make a cheap log that outputs to a big one-way valve and then into the compressor setup. Adjust the exhaust valves so there's no overlap, very near 100% possitive displacement.

Locked in 5th on a DX cable trans would net you 27cfm with a 3000rpm elec motor. Or for real ballers, have a d15 with a cheap carb setup connected to that instead, and crank it to 5 grand.


Yeah, just a dream. I actually have an oil-filled compressor head lined up, I plan on adding that in parallel to another compressor to double the cfm.

I hope you have a hell of lot of electrical service to run the motor required to run that setup.

[mandrel-bends]

How much power you got?

[bigwig]

How much power you got?

I'll have to check tomorrow.  I know I have at least 220V 30A.  I can't comment beyond that.

[t_cel_t]

5 automotive air-conditioning compressors ganged together powered by 2 washing machine motors

[onlyflash944]

5 automotive air-conditioning compressors ganged together powered by 2 washing machine motors

true rhmt right there.  someone wants to do this, i have at least 3 layign around

[HiProfile]

I hope you have a hell of lot of electrical service to run the motor required to run that setup.

Accelleration is what would require a big ass motor, but actual pumping wouldn't need much more (if any) than a regular compressor. You could actually remove the cam completely, replace the intake valve springs with weak units and limiters. Then they'd work like a compressor's one-way inlet valve(s) and double work per rev. That means even at 60rpm (starter speed), you are pumping ~3.3cfm @ ~200psi. A dinky 12v starter can spin a d16 for several minutes on a decent battery. Given a civic batt averages ~300 amps for 30 seconds (300 cca) and only uses ~6 ga wire max, it's less than 60 amps. That means at 120v, the equvalent would hardly need more than 8 amps for a POS AC motor. And that assumes the starter indeed sucks a huge 60 amps.

Now since you're only needing 90psi for a sandblaster, that rating would be more like 7.3 cfm @ 90psi (60 rpm). Use a larger motor, double the speed, and you'd get ~14.5 cfm. Use the tranny, a big Baldor motor (say 15 amps) that will do 2000rpm which the tranny converts to 667rpm in 5th, and you'd have ~37cfm at 200psi. That would be somehthing like 82cfm @ 90psi - and your air pump isn't even at it's engineered idle speed.

Now, this is with an engine/trans you can get for $100 at most (y7), a $50 baldor motor, and some welding. Try to find a compressor head that will come close to 82cfm @ 90psi for $150. Hell, even if your motor can't do 1/2 that rpm from the load, you're still >41cfm @ 90psi, or 21cfm @ 175psi. Grainger charges $881 for 14.5cfm @ 175psi Of course, my math will suck since I'm tired as hell atm.




I was actually thinking of a cooler compressor - an couple of Eaton blowers. You'd have to stage them to get 150psi, but it would work, not to mention look and sound fucking awsome.




BTW Here's something funny I found recently, almost as cool as that home-made welder:

http://www.flickr.com/photos/whiteafrican/162677862#

[HiProfile]

This is for the portable engine-based compressor (real!):

http://www.dunnrightinc.com/


Given the specs, I guess my 10amp blador/82cfm model is a bit underpowered. Still, that would be the cheapest air pump you could find. I also just realized that instead of an entire tranny, you could just put an alternator belt on the elec motor and use the crank pulley to supply power.

[onlyflash944]

This is for the portable engine-based compressor (real!):

http://www.dunnrightinc.com/


Given the specs, I guess my 10amp blador/82cfm model is a bit underpowered. Still, that would be the cheapest air pump you could find. I also just realized that instead of an entire tranny, you could just put an alternator belt on the elec motor and use the crank pulley to supply power.

shits pretty neat.  wonder how many they have sold

[nock]

that thing has been around since before jesus. Dunn-Right Inc. must have bought out volks air or something, they were selling these things in old hot rod magazines from the 70's. people would say that was the only thing a bug motor was good for.

[mandrel-bends]

We ran one of those Black Craftsman "Pro" series which was a dual stage 7.5hp 60 gallon, and it really couldn't keep up with blasting. It would piss in the lines so bad that the traps would get full at an irritating rate and then we'd go through nozzles.

If you had more power you can pickup some smaller industrial compressors off craigslist for cheap. I bought our 25hp ingersol 3ph 200 gal monster with a brand new 3 piston head for $1500. Still cost me $500 for a starter, but it was just a fraction of the cost. I see 5 hp 3ph guys on there all the time.