|
|
Post by aldarith on Jun 23, 2023 0:09:57 GMT
Hey folks!
I have seen Rust Converter products for sale for automotive that purport to convert active rust to ferric phosphate and it has me asking:
Is there a way to do this at home with household materials?
A lot of these converters contain polymers that are presumably there to help stabilize the body of the car and inhibit further corrosion but I'm not sure I want polymer coating on a blade.
I can force a patina using Vinegar, Salt and Water but it's time consuming, and I know the Peroxide and Salt trick for producing a lot of rust FAST, but what about converting that rust to inert patina?
|
|
|
|
Post by mrstabby on Jun 23, 2023 7:05:28 GMT
You can covert any red ferric oxide into black oxide by boiling it in water until it goes black. It will still be a slow process since you need to redo the process a few (like 10) times. But the "superrusting" agent can leave the surface pitted instead of giving a smooth finish, unlike the slower working vinegar. The resulting rust might also be a bit porous when you use H2O2/NaCl. Rustig adds volume and it will swell up and not keep the dimensions it had, not a problem with thin layers, more so as the rust gets thicker.
Cold blueing agents are available, they are easy to use but a bit toxic (so need to take care, do it in a ventilated room with gloves) and the resulting finish won't be as thick and durable as you get from other methods. It works very well and a small bottle will be enough for a big area.
|
|
|
|
Post by aldarith on Jun 23, 2023 17:22:56 GMT
Interesting - when you say boiling in water is the cooling and re-heating part of the conversion process?
I am totally willing to do that, and if you have any process tips I would love to hear them.
|
|
|
|
Post by Sir Thorfinn on Jun 23, 2023 18:14:58 GMT
I posted this somewhere on here, can't find it, so give this a look.
|
|
|
|
Post by aldarith on Jun 24, 2023 4:52:32 GMT
That's awesome, thank you!
|
|
|
|
Post by larason2 on Jun 24, 2023 15:10:10 GMT
It's helpful to know what exactly you are trying to patinate? For Japanses tsubas, Jim Kelso has a recipe for traditional rust patina on his web site: www.jimkelso.com/tutorials/ironpatina.htmIt doesn't have arsenic, so it's safer than some of the other traditional Japanese formulas out there, but it does have some ingredients that can be hard to get (like the potassium nitrate). As Jim mentions though, there are tons of recipes for this. It really depends on what you want to do. Ford Hallam also has a recipe for "Florentine Brown," which was used to darken gun barrels in europe, which is 1 tsp ferric chloride, 1/2 tsp ferric nitrate, 250 ml of hot water. Thinly coat a metal surface that has been thoroughly degreased, leave on a few hours to over night, then scrub off the loose rust with newspaper, and boil in tea. Repeat until the desired patina is desired. Again, it all depends on what you want to do. Different treatments leave different surface finishes. |
|
