Rust and Bar keepers friend

[bigmike13]

Had some surface rust on a mold that I got in trade and Bar keepers friend cleaned it perfectly and left the cavities all shiny and new after about a minute of scrubbing with a toothbrush.

[DLCTEX]

I use Bon Ami, as similar product.

[Greg5278]

Any product containing Oxalic acid will do the trick on Rust. You just need to make sure the part is degreased first. Vinegar works too, but needs a few hours. The rust is converted to Iron Acetate.
Greg

[selmerfan]

So rhubarb leaves would work? Oxalic acid is the poison in rhubarb leaves.

[Greg5278]

I don't believe that Oxalic acid is the poison in Rhubarb. Oxalic acid in Rhubarb or Sorrel can cause Kidney stones of one sort. The poison part of Rhubarb is in the green portion of the Leaves, I am not sure of the Chemical composition. Oxalic acid is useful in it's rust removing abilty. It is much safer than some idustrial alternatives. I believe one is Hydrofluoric acid, which dissolves glass. I wouldn't want to mess with Hydroflouric, especially since Oxalic acid is readily available in some products. Marine stores carry a granular oxalic powder, which requires gloves to handle.
Greg

[Ranger Bob]

Oxalic acid is also used as a bleach for wood and leather.

[JesseCJC]

after the rust is removed, what is a good method for storage coatings?

[MtGun44]

Personally, dry it well and put in an ammo box with a dessicant pack that has been
run in the oven at about 150F for a few hours. Never any rust then, no moisture.
No need to clean the mold before using like you would if you use oil or grease.
Bill