Hot Bluing

[ddickey]

This is an okay method to help prevent corrosion?
Heat part until blue/purple and place in oil.
Any reason why I shouldn't do this?

 

[RJSakowski]

It works, sort of, and I use this method although mostly for decorative purposes. I spray with a coat of automotive clear coat which holds up fairly well. It is my belief that the oxide layer isn't as thick as on a hot blued job and is more easily scratched. I have blackened forged iron work by heating in a forge until red and plunging into oil. The oxide layer that forms in that process is much thicker, like that on hot rolled steel. The oil seems to penetrate the oxide, making it rust resistant. I have forged iron artwork that has stayed rust free for several decades. However, if the intent is to expose it to the elements, just like hot rolled, it will eventually rust.

 

[dulltool17]

Try Rust Bluing. Easy, cheap, and effective.

 

[12bolts]

Hard Beeswax rubbed onto warmed, (finger burning, but not scorching) steel will provide a thin easily scratched layer of protection. Linseed oil does a pretty good job on heated, (blue) steel, and provides a more durable layer. Carnauba Wax is also an option.

Cheers Phil

 

[epanzella]

I use rust bluing on my rifles. Easy to do an very durable.

 

[chips&more]

If the part is heat treated, that process will affect temper.

 

[epanzella]

If the part is heat treated, that process will affect temper.

I assume you're not talking about rust bluing . Rust bluing doesn't raise the temp of a part above 212 deg F.

 

[RJSakowski]

Heat bluing as the OP is describing will take the piece to more than 600ºF and destroy any temper.

 

[ddickey]

Nothing hardened, just 12l14 and some 1018.

 

[ghostdncr]

You might give Kasenit a try. It's fairly cheap, easy to work with, and produces a nice matte gray finish on mild steels. I have absolutely zero scientific evidence to back this up, but it seems that pieces I've treated with it have considerably more resistance to corrosion than similar untreated parts. Plus you get the benefits of a hardened surface. Here's a link to Brownell's Kasenit web page: http://tinyurl.com/k7qhr2c