I have a 14cfm, 100 litre tank compressor which is great for air guns, ratchets and so on, but even it struggles with needle descalers and such like so definitely the bigger the better. Mine is 3 hp so it's hard wired. Most airline connections are 1/4 BSP and the internal diameter of the hose is very important, use 10mm if you can but not less than 8. Losses are high from coiled hoses too!
John
I think you could be disappointed with the small stuff.....a small air receiver would be empty in no time when using a ratchet driver. They are ok for tyre inflation and blow guns, but not too much else.
Why not call into Machine Mart and see what they say?
John
A typical job for me would be a pads/discs change.
Perhaps air tools are an extravagance for that. Another consideration is getting an air ratchet into awkward areas. The neighbors may not appreciate the noise either.
I think you'd be dismayed about the performance of a ratchet wrench, to be honest.....they are rather low torque and therefore undoing tight bolts just doesn't work. You will get a higher tightening torque performance though.
The only time I use mine to any extent is when I'm using spring compressors for example - when there is a lot of turning to do, the work is speeded up.
I think in your case a battery impact driver would be the way to go, or at least consider......I don't own such a tool (yet) but they can do most things that air spanners can, sometimes even better.
John
Sealey have an excellent marketing strategy, nice catalogues and so on - but their prices are usually very steep and finding an outlet near you can be a pain.
My own choice is either Machine Mart or S.I.P for pneumatic gear but as everything else, you get what you pay for!
John
My Aldi compressor is still going strong after 7 years ! I must try the impact wrench with a shorter and bigger bore hose as it's pretty useless otherwise.