Youd be as well getting half a gallon of dulux gloss. The formula isnt that much different and itll dry slightly slower so the paint will relax more and youll end up with less brush or roller marks. Pound for pound it also has more pigment in it and more solids at a similar size so the finish will be shiner and almost as hard. Early enamel was called so to identify the size of the solids. It was ground finer to give a better finish but these days a top quality domestic 'trade' gloss is as good as an old school enamel. ICI produced most of the countries pigments so you got more in Dulux their paint company. This tradition is being held up by todays Dutch owners.
Prep as normal, one coat of thinned undercoat, one coat of thinned 50/50 undercoat and gloss then a final coat of thinned gloss will give you a very good finish indeed. Cutting back to smooth with a fine wet and dry between coats. Dont be tempted to get dulux from anywhere other than a trade center as B&Q and the like stock a DIY formula of dulux and it is made for out of the can application. Its not a patch on the real gear that has to be thinned for any use never mind flatwork. Oh and use white spirit not turps substitute from the same Dulux Decorators Center. Its important
Try and use a good quality 'USED' brush to lay the paint off. Even a house painter wouldnt dream of using a new brush for a front door never mind steel. They must be worn in over time and ask any decorator that knows his onions and he will tell you. A new brush only goes in emulsion for at least six months.
