Needing help on a Mild Steel Finish

[chadolvr]

Hey guys, I am very new to blacksmithing. I have made a set of fireplace doors for my grandmother, and the material I used had been sand blasted. So I am trying to figure out how to get black finish back on it. If I use the Beeswax, Turpentine mixture, will that acheive the look that I am after?

 

Any help is greatly appreciated, and thanks in advance.

 

Chad

[son_of_bluegrass]

Maybe.  There are many finishes that give a dark color to metal.  Some need to be applied while the metal is hot, others not.  

One solution is a high temp paint.

Beeswax, other waxes, oils and mixes involving these are generally applied to hot metal and color can vary depending on the specific wax/oil and the temperature applied.  Alternatively, they can be applied cold and then heated.  The temperatures required to achieve a darkening are in the range of 300 to 500 F.

There there are various cold and hot blueing solutions.

Or you could heat until the oxide colors turn dark (for black you're looking at the range of 650 to 800 F) and apply a protective finish over that. 

Or you could let it rust and apply rust converter, that usually achieves a dark finish.

 

Now what questions do you have?

 

ron

[Jim Coke]

Greetings,

 

When you get right down to it fire place doors don't get that hot.. Look in the store and you see them made from brass and glass...  SANDBLAST ????

Now that you have Rustolem and other high temp paints are your only soloution.. If you read the can they suggest that it is applied without primer...

I would question the use of regular primer and paint....  You could also gold plate them for grandma...

 

Good luch with your project...

 

Jim

[chadolvr]

Son of Bluegrass,
That is an interesting thought about the rust converter, would you have a recommendation for a converter? Also you mentioned heating until the oxides turn dark, are you meaning that I should heat the solution to these temperatures that you mention, or heat my material, and then apply solution. Sorry if that seems redundant, but I am on a short time frame to deliver to her newly remodeled home. So I am trying to not make to many mistakes. Also I thank you for your time, and help.

[son_of_bluegrass]

The rust converters I've use have been based on phosphoric acid, they work by converting the iron oxide to iron phosphate (at least that is my understanding).  The iron phosphate then inhibits further rust.  For them to work, there needs to be rust.  Which means if you have clean bare metal you need to get it to rust before it will work.  And unless you can get the rust to happen evenly, don't expect the finish to be even.  Naval jelly is a common rust converter (sometimes called rust remover), there are others, I've use a rattle can for applications with lots of nooks and crannies that would be difficult to get to otherwise.  There are different concentrations requiring different levels of protective gear and different procedures and clean up recommendations.  Anything off the shelf should work, read the labels and decide what you want to try.

 

So far as heating until you get dark oxides, have you ever heated a piece of clean steel and watched it change colors?   Starting at a light yellow and progressing to blue then turning dark?  That is what I'm saying here, it is a way to achieve a dark appearance.  For this method you heat the metal until the color is what you want.  Since the oxides tend to be a thin surface layer, it is easily marred.  Thus the recommendation to add a protective finish.

 

As for the wax/oil mixes, these take some practice to get consistent.  I've done these a couple of ways depending on the heat source handy.  It can be done by heating the metal and carefully applying the wax or oil. The wax or oil should smoke but not burn.  Or the wax or oil can be applied cold then the item is heated until it smokes.  The exact color you get depends on the wax or oil used, the heat applied, how long it's held at temperature and whims of whatever gods happen to be in the area.

 

For a something with a short learning curve and few mistakes, a rattle can of paint formulated to take the heat is easy.  Stove paint, bar-b-que grill paint, I believe there are automotive paints are generally readily available.

 

ron

[K. Bryan Morgan]

This is what I do.  When I'm done forging my piece I wire brush it to remove scale then heat to a black color.  Then apply bees wax.  The finish is perminant.  I then wait for it to cool and buff to a nice semi gloss with a cotton towel.  It makes for a very nice finish.  And its quite durrable in this Alaska invironment that I live in.  I've had pieces that I have not had to re touch in over 3 years.