Air compressor - Assorted questions

Discussion in 'Off-Topic' started by atferrari, Dec 8, 2010.

  1. atferrari

    Thread Starter AAC Fanatic!

    Jan 6, 2004
    Planning to buy a small air compressor but not clear what exactly; it could be even one of those used to inflate tires.

    I want to clean PCs / equipment gently but effectively and I want it to have a small tank (reservoir?). It will be used for an aerograph and small air-driven machines.

    My questions:
    How do you call in English the valve regulating the pressure at the output?

    I want it adjustable so how to tell what range it should cover?

    Those 12V units, are they worth the expense?

    What else to look for besides a filter / water trap?

    Oil, is it a no-no for what I want it?

    Found what locally is called "dentist compressor", fitted with a tank and small in size.

    Always took for granted compressed air. Now I know that I know nothing about.

    Please, few short sentences preferred than googling and reading long articles. Little time available here. Believe me. :mad:

    The local tradition in the shipping business say that by December everything slows down. Not true. Full ahead as ever. Always. For years.

    Why people insist in repeating legends? :confused:
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    I have a small compressor with a medium size tank that can handle around 100 bar

    Pressure should be enuf to inflate car tires.

    This way I can tell I can have high pressure if I need to..

    Water trap is important if you plan to clean circuit boards.

    Pressure regulator is sometimes useful for sensitive blow.

    One thing I found useful was small cylinders that I can carry. I can top up with air.
    Use pressure valve and small high pressure air gun to dust away in hard to reach sites and places
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    Pressure regulator. There are single-stage and two-stage. For most purposes, single-stage is adequate. Two-stage gives better control of the output with varying input pressure.

    Up to 125 psi is common, but some go higher. You need at least 90 psi for some pneumatic tools, like big wrenches. For work like you describe, 125 or less should be sufficient. For cleaning and inflating tires, 40 psi is probably enough.

    Air compressor output (volume @ pressure) can be expressed in horsepower. A 12-volt compressor will be low volume. They are good for some things, like emergency inflating tires, but I would not consider one, if I had access to the mains.

    I think it might be, depending on what you mean by "cleaning." Removing oil is hard to do. Oil-less piston compressors and various turbine designs are pretty oil free. The turbine/screw designs can get pretty expensive. There are also low-pressure diaphram compressors that are oil-free.

    Don't know what that is. It may be a diaphram or small oil-less compressor. Fish tank compressors are often diaphram type.

    Remember, compressed air is hot and can contain lots of water. Continuous, high-volume production requires a cooler and drier (water remover). When I have done really sensitive spraying, I have passed the air through a multiple-turn copper coil immersed in an acetone/dry ice bath or just plain salt-water ice. Refrigerated coolers are becoming more practical now, as there are some cheap imports on the market.

    Last edited: Dec 8, 2010
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    You would be better off getting a marine trolling motor deep cycle battery and a decent 120volt inverter(600-1000W) and just running a small mains powered compressor off of that. Good for camp sites and off gird adventures. If you go mobile the inverter can be attached to the car battery and run that way. Then at home you just plug the compressor into the wall.
  5. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    there are compressed air refillable aerosol cans. using one of those without a fluid component would give you a portable/refillable canister of 'air'. you could refill it from the small compressor you have in your vehicle. ;)
  6. VoodooMojo

    Active Member

    Nov 28, 2009
    an air brush uses only a few cfm of air flow at 20 to 40 psi.
    the air driven machines are the concern
    you will need to know the cfm at what pressure ratings for the air motors you are going to be using. If more than one motor is being driven simultaneously, you will need to add the cfm totals to determine the delivery rate of the compressor you buy.
    never buy a compressor smaller than what you need and you will never be disappointed by purchasing a compressor larger than needed.

    regulators, dryers, and other assessories are available for purchase