Hi Cary,
Capacity that I will need. With the sandblaster I only need a
1/2 hsp motor with a small tank, I figured that if in the
future I would possibly be running both machines it would be
better to buy a bigger machine to compensate for this, I
figured that I needed double the size.
The size of your compressor should be based on the requirements
of the tools, applications it will be used with. In the US, most
pneumatic tools list the air consumption in terms of cubic feet
per minute (cfm) and maximum pressure, pounds per square inch
(psi). In other counties other units of measurement are used,
but the idea’s the same, a way to measure volume of air used per
unit of time & maximum pressure. Check the specifications of the
tools you want to use with the compressor. If they require
different pressures (psi), use the highest pressure. If more
than 1 tool will be used at a time, add the cfm requirements of
all tools. Double the cfm requirements for safety.
To power a tool, a compressor must be capable of producing air
at the require volume (cfm) and pressure (psi). The 2
requirements are at opposite extremes, as the required pressure
goes up the compressor’s ability to produce the volume at that
pressure goes down (and vice versa).
Using sandblaster is similar to keeping a compressed air hose
open (to the size of the nozzle) 100% of the time. This
application requires lots, cfm, of air. A wax injector on the
other hand, requires a relatively small amount (about 1 cu. ft.)
of air, just enough to pressurize the wax pot to a given
pressure.
One characteristic of compressors with small tanks and low cfm
outputs, is they run a lot. The compressor running for extended
periods can be annoying and the unit may not be rated for that
large a duty cycle. Some may not be able to keep up with the cfm
requirements of sand blasters.
The horsepower rating of a compressor is an indication of the
maximum pressure & cfm output. The lower the hp rating the lower
the capacity of the compressor. Getting the larger hp (within
reason) unit will prevent future frustration when using it.
Sandblasting requires the use of ‘dry air’. When air is
compressed, it looses some of the moisture it was holding. This
moisture accumulates in the compressor tank as water. If not
drained periodically, you may get water mixed with the air &
this ‘wet air’ might affect the performance of the tools being
used. Be sure the compressor tank has a drain valve on it. The
drain valves are usually located on the low spot of the tank.
Sorry, I can’t give you any personal use reccomendations for
Coleman of CH, I use a larger industrial type compressor.