View Full Version : Air Compressor

08-21-2005, 02:41 AM
Hi Guy's To operate a Bead Blasting Machine I intend to purchase the Machines instruction brochure states to run the machine successfully it needs to be supplied by an Air Compressor capable of suppling 5 CMF. at 85.PSI

The question is how do I decide what size compressor I need with a little in reserve ???

Most Cataloge list Air-Compressors as so many H.P.& the Tank Capacity in Litres here in Australia

Is there a standardised reconised rating for Air -Compressors dependent on the requirements of the Machinery it is intended to operate.?????

I look forward to your advise & Many Thanks for same.

Best Regards. Jack
www.jackerskine.com (http://www.jackerskine.com)

08-21-2005, 04:12 AM
Look at page 856 of http://www.mcmaster.com/

Just type 856 into the "find" box.

They give the CFM rating of the compressor at the max PSI. Since the max psi they show is more than you'll need, you can use one with a little less CFM. They also give the HP of the motor. You can use that info to get an idea of the size unit you'll need.

Hope that helps.

08-21-2005, 08:12 AM
SCFM @XXX PSI give you the actual delivery of a given unit.

From taking the shop tour on your website (nice btw)I see a guy who is going to need more air in the future.If you can swing it I would look at a 5hp two stage compressor on a 40-60 gallon tank.If you got the room(outside the building under it's own roof is best IMHO)that's what I would go for.

Forrest Addy
08-21-2005, 01:00 PM
Here's standard prectice for specifying compressor delivery. Pick one having twice the delivery of your heaviest use. Conpressors that run continuously have far less than half the rated service life than when run ar 50% cuty cycle.

A bead blaster could be considered a heavy air user depending on the size of the air orifice in the nozzle.

In your case you'd need at least 10 CFM for your 5 CFM bead blaser (a very small rating, one that make me skeptical of its rated consumption).

10 CFM @ 130 PSI would correspond to about 2 US honestly rated HP (label plate rated at 10 Amps at 230 volts single phase) or 1.5 KW (rated metric motor output).

The compressor wlll not sigificantly increase its delivery just because it feeds into a lower pressure eervice. If you want to increase delivery so the motor works to its ratings for a lower pressure you need to speed up the compressor pump so it makes more strokes pwe minute.

Speeding up a compressor must be done with the motor's available mechanical output and electrical ratings in mind. Boyle's Law enters the equation.

Dr. Rob
08-22-2005, 02:12 AM
Been thinking about the same thing. About your thought on extra capacity Jack, consider connecting an extra storage tank from anything anywhere (okay, maybe not anything) but just something that holds more air at your compressors max PSI.

That's what I do... I have only a tiny little airbrush-sized compressor, but a HUGE extra tank. Takes forever to fill, but it works for me since I only use it sporadically to blow chips off parts and such.


I was also considering upgrading myself to a bigger unit for sandblasting and such. BUT I have a problem with noise. The compressor I have now sounds like a refrigerator, brrrrrrrrr. My buddy has one from the auto parts place that sounds like a darn M-16 on full auto, BABABABABABAM. Unacceptable!

So what are the different types (piston vs what?) of compressor, and how do they fit in price / performance / availability wise?

(Hmmm... My neighbor has a big quiet one... maybe I can run a looong hose from his)

08-22-2005, 04:10 AM
Hi Guy's Many Thanks for all the greatly appreciatted advice re the Air -Compressor at least I have a clue on where to start.
Best Regards. Jack.

Your Old Dog
08-22-2005, 06:03 AM
sorry, double post after correction

[This message has been edited by Your Old Dog (edited 08-22-2005).]

Your Old Dog
08-22-2005, 06:05 AM
No expert here on this matter for sure but would seriously advise against "pancake" style compressors as they are the really loud ones. I have an old fashioned one that needs oil periodically but has a very muted note to it. My friends oil-less job will cause you to go deaf with it's staccato noise!

Nice shop/product line........

08-22-2005, 06:05 AM
for less noise from an air compressor you will want a belt driven instead of a direct drive, also you can get a muffler for the intake that will decrease the noise level

Matt in AK

08-27-2005, 01:58 AM
Hi Guy's My search in our town has brought me to the point that I'm about to purchase on very strong recommendations from the Mfg's an Air Compressor to run the Blast Cabinet as previously discussed,

The infomation is the Machine is made in Italy-- Belt Driven & rated at 15CFM.-- 3hp Cast Iron V Twin- FAD:251L/min. price $695.00 (Australian $) $460.00.US. approx.
Am I on the right track or need to re consider,?????

Many Thanks in Anticipation

Best Regards. Jack .

08-27-2005, 12:50 PM
Your in the ball park. I went through this a couple of years ago. I actually did a limited amount of bead blasting with a small 1 hp compressor on a 20 gal tank. It worked but nor very good. I went with a 5 hp single stage compressor and it will cycle off while I am blasting. The point someone made regarding noise has surprised me. I located the compressor and rotophase outside under cover to get the noise out of the shop. When the compressor comes on you can hear it 100 yards away on the patio. The other surprise that I got regards the moisture that travels throughout the system. I drain my tank reguraly. I laid galvanized pipe from one bilding to another. This was buried because fork lift and heavy equipment runs over it. Acouple of the access points are hard to purge of moisture that collects in this buried metal pipe. Good luck with your blaster. You will find a lot of uses that you never thought of before you got one.

Alan in Oz
08-28-2005, 07:32 PM
I think you are on a winner with that set up and the price is good also compared with Perth where its about $200 more. Maybe I'll have to move. Allthe best.

08-29-2005, 07:30 AM
Hi Alan . Many Thanks for the re-confirmation , hopefully now I'm all set up-
As you know the type of small work I'll be doing , similar to John D. what do you suggest in the size or gauge ??? of the Glass Beads. I should use.???
Also hopefully I'll be in Perth latter this year to visit John , & hopefully we may be able to hook-up,

Best Regards. Jack.
www.jackerskine.com (http://www.jackerskine.com)