Hiya,
I'll put in my couple cents on this. I worked for a Dupont distributor for 8 years that specialized in industrial and automotive coatings. I would suggest that since your abrasive blasting the equipment and starting with a bare surface that you use a metal prep solution to oxidize the steel for primer adhesion. You can use a sealing primer such as Dupont sand n seal or Sem coat then apply a non catalyzed enamel top coat observing drying times of all layers. If possible, set the implement in a baking oven for 4 to 6 hours or for several days in hot sun, that should set the top coat and offer maximum adhesion.
I would strongly advise against using catalyzed enamel if you do not have a proper supplied air breathing system. The polyisocyanates in the catalyst will cause nerve damage. Read the MSDS sheets, they will scare the S out of you. I know people that have been effected by them for not taking the warnings seriously, it is not worth the risk.
Tom