Rust

[comdiver]

I have a few molds that are rusty. What is the best way to clean it off.

[imashooter2]

I like Electrolytic rust removal. Lots of others like Evaporust. Some use citric acid or vinegar. Lots of threads on the subject. A quick search will turn up hours of reading and discussion.

[comdiver]

thank you

[gwpercle]

Don't use any power tools or wire wheels or wire brushes. A lot depends on how rusty and where rusty. A good soaking in PB Blaster Penetrating lubricant , kerosene (hurricane lamp oil), kroil , Liquid Wrench Penetrating oil or any product designed to loosen rust would be a good start. soaking will not damage the mould, you can let them soak for a month or two. Then go slow and easy and use copper wool to remove any rust. Hensley and Gibbs has a good " how to clean and remove rust" directions on their web site.
Gary

[94Doug]

This also depends on what you are referring to as rust. If it's a light dusting of surface rust, you sure can use a copper gun brush and lightly clean it off with no finish loss. Clean with oil when done.

Doug

[William Yanda]

Citric acid bath will loosen rust. Warmed up the reaction is faster. Coke will leave a phosphate coating that will resist rust.

[longbow]

This is why I oil all my moulds after use. Even brass and aluminum moulds have steel parts that can rust.

As mentioned, if it is just light dusting of extremely fine rust it can be removed safely a variety of ways. In fact, if it is a really light dusting I would probably just wipe it with a rag or some copper/brass wool then cast with it as is.

I would not use anything aggressive that isn't designed to be used for rust removal. There are products like Naval Jelly (phosphoric acid base and Evaporust that dissolve rust and do not harm the parent material though apparently long contact with phosphoric acid can etch an iron mould ~ I have never seen this but...

Also as mentioned, don't use aggressive mechanical methods to clean off the rust. Things like steel scrapers, sand paper, emery cloth and tumbling can and likely will damage the mould

I have used Naval Jelly to clean up a couple of old moulds and it did a good job for me. It will remove the bluing as well though, not sure about Evaporust. If you heat the mould up just past regular casting temperature it will heat blue or a coating of cold blue will help protect it.

After use when the mould is still a bit hot to the touch, I wipe it down with oil and make sure all surfaces are coated. I also put boolits in the cavities so that they keep the oil on the cavity surfaces through capillary action. I have never had a mould rust doing this.

I simply wipe the oil off next time I set up to cast then pre-heat the mould until it just starts to smoke, then start casting.


YMMV but it works for me.

Longbow

[zuke]

Tumble in SS media, each 1/2 seperately

[cajun shooter]

Use Evaporust, It's unreal results will surprise you. I purchase it from Lowes. They had a sale on them about a year ago and the manager had 12 bottles that he sold me for $1.00 ea. Later David


PS Be careful if you use it on any blued gun parts as it will strip all the bluing. Don't ask me how I know