AggieBlacksmith

Cast iron skillet finish on cast iron brake rotor? Is it possible?

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Howdy Yall,

As much as I have searched, I haven't been lucky in finding an answer to this question. I'm going to be making a brake rotor forge for my backyard and from everything that I have heard, these things are made of CAST IRON. However, after I clean the rust off, the rotor is shiny silver. I DON'T WANT THAT. I like the cast iron, black, seasoned finish and would like my brake drum forge to imitate that. There's no way that seasoning it would get it from shiny silver to skillet-black either, so I'm at a loss at what to do.

Any ideas?

Thanks

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@Charles R. Stevens I've seen some examples of that and it's definitely given me some good ideas, but no demos that I have seen have tried to create a black finish from something shiny silver. Most steel that I've seen seasoned is the color of regular stock (dark, cold grey). 

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The problem is that the forge may run hotter than the oil finish will allow and burn it off.   Have you thought of rust bluing it?  Or finding an old patinated rotor and just removing any loose rust and using it.  With the scaling of the surface in use it will darken!

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@ThomasPowers I agree regarding the oil finish. I've looked at rust bluing a little, but honestly it doesn't turn the metal very black. It's still at kind of a mid-range darkness grey color. What exactly do you mean by the scaling of the surface darkening though?

Maybe I just need to call up one of the cast iron skillet makers and ask what their process is. 

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The cast iron skillets are seasoned by rubbing cooking oil on them and placing them upside down in a 400F degree oven for an hour. They are made from a different cast iron than brake rotors though, which is an alloy G3000. Just use it and it will blacken from the fuel & heat.

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Build a fire, toss the rotor on. When a drop of oil on it bursts into smoke or better yet flame, remove it and brush it down good with oil. Another way to blacken it is to use Alex Bealer's finishing recipe from "The Art of Blacksmithing." It's basically melt wax, add lamp black and turpentine to suit. I used enough turps to make it like shoe polish but it evaporated out in a couple years leaving it wax block hard. 

I just used paraffin because he didn't specify a reason not to and it's been a pretty durable finish. I have things that have been out in the weather a good 25 years and not a spot of rust.

However, the outside of a fire pot is something else, maybe just use Naval Jelly, that's phosphate BLACK, spray the results with a high temp spray oil, say Pledge furniture polish. It's silicon and will withstand a surprising amount of heat.

Before you get all involved in this you might want to examine WHY you're building a forge. If you want yard art then use paint, Rustolium makes a lot of "wrought iron" paints. If on the other hand you want to make a working forge who cares what color the fire pot is? Seriously, will cosmetics effect how it works?

It's your shop your rules, no problem. I'm just asking if you've thought about it from this perspective.

Frosty The Lucky.

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I don't understand why you want to patina the brake rotor before you use it. As others have stated oil finishes like on cast iron cookware won't really stay "nice" like it would start out. Just use it. It will get a wonderful black sooty color.

In the pic the one spot is shiny as I had just re welded the hole plate it and needed a good ground. 

You are using coal, right?

image.jpg

image.jpg

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@Daswulf The patina is really just an experiment. In the end, you're right, it won't matter at all, but I'd rather be looking at a forge with a nicer, black finish than a rusty old hunk of metal. 

Nice setup. 

And yes, I'll be using coal.

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Well for a quick blackened look the oil and heat mentioned above will get it a look until the coal does its job. 

I can see where you are coming from. It's all aesthetics and taste or just personal preference.  

getting the thing fired up might just bring you more joy. ;) 

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