surface rust

[bishopgrandpa]

What is best way to remove surface rust from mold?

[Bent Ramrod]

If the surface rust is just "there;" no pitting or anything, I spray it with WD-40 and rub with #0000 steel wool. Sometimes, even a coarse paper towel is enough to remove it. If it's a little heavier or more persistent, I use Liquid Wrench instead of WD-40 and soak the piece for a while.

If I have something going where I have boiling water handy, I drop the piece in the boiling water and leave it for a few minutes. Depending on your elevation, the red rust will convert to black rust ("bluing"). Most will come off (or rub off when I dry and oil the piece) and the rest will be indistinguishable from whatever blued finish remains on the piece.

I've also just put handles on the mould and cast a bunch of boolits with it. Generally, the rust is either "blued" as above or otherwise not in evidence by the end of the session.

Again, this is the light haze of orange that (to me) is what the term "surface rust" denotes. Heavier rust accompanied by pits can also be boiled away (depending on the size and depth of the pits), but generally requires the steel wool treatment, if not lapping or more extreme desperation measures to remove.

[405grain]

Whatever you do, don't try scrubbing it off with a wire brush. Doing that will all but destroy a good set of molds.

[45DUDE]

I have a bead blaster and use a fine sugar sand with low pressure. Could you post a photo? If you were a neighbor I would do it for free -or you could use my equipment.

[M-Tecs]

Evapo-Rust https://www.evapo-rust.com/

[JonB_in_Glencoe]

oil and denim, is what I use.

[gwpercle]

Surface rust ... I like to soak it in Kerosene for a couple days and then scrub away with 0000 steel wool dampened with more kerosene .
Kerosene is gentle and an old school rust removing agent .
I've saved a lot of rusty "stuff" by doing the kerosene Soak & Scrub on it .
Old school method but it still works .
Gary

[Taterhead]

Evapo-rust works great!

[MT Gianni]

Take a #2 pencil, the oldest yellow one you can find. Sharpen it and go over the mold with the graphite, concentrating on the rust. Then break the point off and go over it with just the wood. For decades, until the early 00's the wood was Osage Orange. It should get the rust off and give it a slight lube.

[Jack Stanley]

The boiling method would work , if it's a little more rusty than light soak it in your favorite "cola" . The acid in that will work and washes out with water easy .

Jack