Cooking on a grill made of mild steel is fine, provided there is no dangerous electro plated metal on it llike cadmium or a less poisonous metal, zinc. If it's unplated soft steel, you're fine.
To season the steel, get it as hot as possible to burn off any impurities on the steel, then get an paint brush or damp rag and slap the steel with crisco oil. Let it burn on really good and black. Allow the steel to cool and put more crisco on it until it turns good and black like a cast iron skillet.

....and like magic, your grill surface is now "seasoned."

 

Awesome, thank you

 

This is a timely topic, as I'm planning to build a table/stand for this: http://www.northerntool.com/shop/tools/product_15490_15490
I expect I'd have to season it to help keep the areas near the burner from rusting.

 

just paint with high heat paint, that will keep the rust away...

 

The grills that I've seen that have a coating are coated with some kind of ceramic glaze that turns into almost a form of glass.

I don't think the carbonized oil coating that we use on frying pans would hold up to the heat of a barbecue, and I'm not sure I'd want to eat anything that was cooked on paint, either.

 

I usually just wash it really good with soap and water to get rid of any oils, heat it up to dry it off, and wipe on some vegetable oil to keep it from rusting. Keep it oiled up after each time you cook on it

 

I assume you guys take the mill scale off of it first too?

 

I wouldn't really worry too much about mill scale. Propane tanks are used pretty often as the smoke chambers on smokers which can have all sorts of odors/coatings/etc...usually you just do as SuperArc said and burn the hottest fire you can burn in there for a good amount of time and it takes care of business.

ETA: Here is a good website/forum with ALL kinds of information related to cookers. www.thesmokering.com

 

Mill scale on mild steel is just a form of iron oxide that forms on the surface when the hot iron reacts with oxygen in the air during the hot roll process. Removing it would just expose the unreacted iron. I'd leave it on and not worry about it other than use some high temp vegetable oil to keep the surface seasoned, which is basically trying to keep air and water from the iron, so it doesn't rust, by filling the pores with oil.

Which reminds me, I need to make a new grill for my propane cooker.

 

Leave the mill scale on if you want something slightly less prone to rust.
Take it off if you want something more pretty and uniform looking.

 

Mild steel is fine to use. I used expanded metal on my UDS, works fantastic.

See..................

 

People used to cook on cast iron all of the time. You have to season your cookware. That means don't wash it with detergents and let the fatty oils build up some. The oils that come naturally from the food you cook will keep things from rusting.

 

I suggest Anodized Cookware as I have done huge research oh cookware.So I know the good results of Anodized Cookware.

 

Years ago almost every family I knew had an old cut in half 55 gal drum out back with some rebar rods across the top and a chunk of expanded metal for a grill in the backyard.
BTW
Powder Coat will burn just like paint!