cleaning iron parts

[greghaa]

All

I have been rebuilding this lathe/mill machine. I have done electrolysis on some of the machined parts that are
plain iron and they come pretty clean. But I have seen other restorations that those parts come out looking new.
I know after the rust sets in there are these black lines deep in the iron. Is there any way to get those parts looking new
again without machining them? I have read about citric acid and I think another type of acid to clean these parts.
I have powdered citric acid and am wondering can I just mix it with water and use that? What other agents have people used to get the iron
shiny and new again without the use of cutting tools or any machining. Electrolysis got me 98% of the way there. It's that last 2 %
that is bugging me.

Any input would be greatly appreciated.

-g

 

[pdentrem]

Maybe someone can step in and tell us about Evap o Rust. I have seen it but never used it. Maybe it may work, I just do not know.
Pierre

 

[ScrapMetal]

I love the evapo-rust but I'm not sure that those "lines" you're seeing are even rust. I see the same thing happen with the evapo-rust depending on the metal. The electrolysis should remove every bit of oxidation so what remains may be some kind of discoloration but not "rust". We'll need someone who really knows their way around steel to fill us in on what you're dealing with.

-Ron

 

[pdentrem]

You could be right about the dark lines being grain structure or flow lines etc. Think of Damacus steel for example.

 

[greghaa]

That's exactly it. Like dark lines on the grain. Small sections of grain lines are stained or something.

All rust is gone, but it just has this darkness to it because of the tiny stains. I have tried scrubbing
with baking soda but I know citric acid can be harmful so I am reluctant to try it. I should find some old
piece somewhere with the same problem and try on that maybe.

--

 

[brucer]

how about naval jelly?

 

[ScrapMetal]

I've got a lot of stuff that needs rust removal as well as stuff that has the "stains" we're discussing. I'll start to play around with it a bit and see what I can come up with.

-Ron

 

[GK1918]

I think you are trying to achieve that fresh machined look. I have wrote this somewhere before. I like
the fresh look also, like lathe ways mill, shaper tables and these surfaces develop age spots or blemishes,
that your eyes just focus on that I can't stand. May sound silly but shoes get shoe polish, cars get waxed,
so, I brush on (silver) never seze right out of the bottle rub it in polish with paper towel. I just figure
this stuff sticks on your fingers so why not, it wont hurt anything. Nice clean look.

 

[ScrapMetal]

I think you are trying to achieve that fresh machined look. I have wrote this somewhere before. I like
the fresh look also, like lathe ways mill, shaper tables and these surfaces develop age spots or blemishes,
that your eyes just focus on that I can't stand. May sound silly but shoes get shoe polish, cars get waxed,
so, I brush on (silver) never seze right out of the bottle rub it in polish with paper towel. I just figure
this stuff sticks on your fingers so why not, it wont hurt anything. Nice clean look.

Interesting. I may give that a try. The stuff stinks to high heaven though it's not so bad after it's "rubbed down" a little.

-Ron

 

[ScrapMetal]

Did everyone see these videos on cutting cast iron and steel?
http://www.youtube.com/watch?v=XZh6WGR16q0
http://www.youtube.com/watch?v=uwh3ouvzSLk
http://www.youtube.com/watch?v=-TfNouJbJrg

Looks like chunks of iron with spaces filled in by carbon & other stuff. I have a feeling that rust (iron oxide) is simply leaving the carbon & other stuff behind, which is the stain we are seeing. We can get down below it to get a nice surface, but we lose whatever was left of the original surface in doing that. We can sand it down to that original surface and use Naval Jelly to convert what's left back into iron, but it's not a durable surface in my experience. I kinda like the suggestion of Never-Seeze, but won't it wash out with oil?

And it will still "rub off" a little on your skin. That stuff is almost as nasty as "prussian blue" when it comes to spreading around, aluminum paste everywhere.

I brought home a couple pieces this afternoon with the intent of experimentation. Think I'm going to try and start with Flitz metal polish and go from there.

-Ron