This is a pic of my middle son Casey's very first attempt at air abrasive work. Its a Phareodus that he found (in pieces) and is now cleaning it with 50% bicarb and 50% dolomite mix. Being a bit scared and nervouse I could see that he was being too cautious. I wasnt worried, I had the media flow turned down a little and the pressure was at about 40 psi. I had him start on the head bones so he could get a feel for it and not ruin anything. I think he's just getting a handle on it.
RB