compressed air an idiots guide

since compressors and air tools go pretty much hand in hand with car modifying i thought i would post a guide(?) to help people get the most from them
first an air tool setup is going to be expensive so have you considered the alternatives
such as this for an alternative to a DA sander
www.argos.co.uk/static/Product/partNumber/0073312/c_1/1|category_root|Garden+and+DIY|14418702/c_2/2|cat_14418702|Power+tools|14418763/c_3/3|cat_14418763|Sanders+and+grinders|14418766.htm
and this as an option for paint spraying
www.argos.co.uk/static/Product/partNumber/7113024/c_1/1|category_root|Garden+and+DIY|14418702/c_2/2|cat_14418702|Wallpaper+and+decorating|14418953.htm
i don't know if this type of product is any good for automotive work as i haven't used them myself so if anyone has could they please add their comments,
but back to the chase for compressed air nirvana
choosing a compressor is pretty much biggest is best but with a couple of points to be wary of
3 hp is (AFAIK) the biggest you can operate from a 13 amp household socket
if you are using an extension lead to supply electric ALWAYS unwind it fully or you run the risk of it catching fire
a large receiver is useful when you are using tools or spraying but a pain if you just want to pump a tyre and have to wait ages for pressure to get up

deciphering the technical specs
CFM=cubic feet per Minuit=how much air pumped
FAD=free air delivery what the compressor pumps against no load
PSI=pounds per square inch
BAR=metric version of psi (1 bar = about 14.5 psi)
most air tools cfm is rated at 90 psi but most compressors are rated fad so if your tool needs 4 cfm you will need a compressor rated higher IE my 2.5 hp compressor which is rated at about 8 cfm will only just keep up with tools rated at 4 cfm
most hobby compressors operate at 120psi but some run at 145psi and the higher pressure will give you more oumph to your tools and more reserve
my compressors peak at 120psi so to get the best performance i run the tool until the pump kicks in then stop to let the pressure build then before it reaches its cut off point i start again so the pump is running whilst i am working
but anyway here is a picture since you must be bored of reading by now

these are the two compressors i use. a 2hp 50liter and a 2.5 hp 25 liter i bought from aldi
i found the 2 hp couldn't keep up but the aldi one does (just) but if i get really keen i will run both together
a couple of points to get the best from whatever compressor you use
the air filter they come with is pretty poor so try and fit a better one (aldi one still to be done!)
when operating they need plenty of fresh air so don't box them in

next bit is the connections

this pic shows some of the types available
the top one is a hose tail for connecting flexible pipe to your choice of connector
the second down is a pcl (common garage/body shop connector)
next is a uni(?) often supplied with hobby air tools etc
finally a couple of less common ones bayonet and schraeder
but remember buying fittings can eat a pretty good wedge so allow for this in your pricing
also some of the cheap connectors/airlines can be small bore and so restrict airflow and hamper tool performance


here we are getting to the toys
cannot really say a lot about spray guns as it is a bit of a dark art to me but the degreasing gun is also useful for spraying waxoyl
and if you get a DA sander there are two types of pad available one for sticky disks and another for Velcro type which are more expensive but seem to last better

here we are with a few die grinders/sanders
the trick about these is the range of attachments
the 90 degree one on the left is fitted with an ata disc holder which sanding and polishing disc's clip too

these are available in a range of sizes from 3" down to 3/4"
with different grit sanding disc's and grades of scotchbrite
the straight ones on the left have different grades/sizes of flap wheel


will come back and bore you some more with hot air about compressed air
ttfn Glenn