if I was u id just change the blast nozzle on the cheap pot to a carbide one and try it out then if your reasonably happy with it change the metering valve . use -- -one 14cfm comp and if its just to say usable buy another and work your way up -- 2 comps and an uprated - pot wont be more than 400 quid
Already got a 3mm carbide nozzle for it but will probably need to go bigger when I uprate the compressor, I did have a bit of a brain fart today though, would it be possible to drill out the 3MM carbide nozzle to something bigger like a 4mm when the new compressor came?
The pot constantly blocks I can't run it for thirty seconds without it blocking, it drives me utterly bananas sometimes. This is why why spending money on it now to get the back of the problems.