best protection for steel hull

I have read some treads "Powder coating" and so on...But it wont get any clearer to me?! What is the best protection for steelhull?
You can check my tread here http://www.boatdesign.net/forums/metal-boat-building/boat-building-progress-31503.html#post344900

 

Powder coating requires the object to be heated to 200 C. for 10 minutes after electrostatically applying the powder.

I have a vivid imagination, but I doubt that shoving a steel hull in an oven is feasible.

 

The individual plates would have have to be done before welding...

 

(My guess to about the powder to, have done some A-Ford frames in the past!) The next best thing to protect the steelhull then? couple of years ago I put on some JOTUN coulor for the ship industri. but today I see the same Jotun falling off the hull. I put it on with a "Brush"( don't know the english word?) But obviosly couldn't get a real grip in the steelplates...Could need the help from you.
Hakan in Swe

 

no short cuts, blast, 75 microns dft zinc, 250 microns qualirty 2 pack epoxy like altex devoe 231, awlgrip number one etc Film thickness is everything on steel
search in the forum cos this has been covered a squillion times,
DFT= DRY FILM THICKNESS, as wet film thickness = wft
25 microns in one thou

 

Arc sprayed Zinc/ Aluminum(85/15) covered with paint.

 

Thanks friends!

 

Lead paint, or coal tar epoxy.