I got a regular art airbrush from a friend. I have never used one. Will it work the same as one bought specifically for cake decorating ...only I will use the airbrush food coloring? Or is there a reason why I would need to buy the brands made specifically for decorating cakes?

It's the amount of psi from the compressor you need to be concerned about. I don't know how many psi are in an art airbrush, but I think my KopyKat airbush is 0 to 30 psi? Too much psi will blow a part your icing.

Before i decided to decorate cakes i actually gave airbrushing a go. I didn't like it but kept my airbrush that i used, it's a badger. I have used it a couple of times on my cakes and never had a problem with it. I'm not sure of the psi's??? but it works fine.