Rust bluing slipjoint

[ISKski]

I am working on this slip joint (A2) and once the blade is ground I want to slow rust blue it with the vinegar/peroxide/salt method.

Do I have to mask off any areas ? Or can I blacken everything … as it sits the walk and talk are right where I want them…

 

[Stacy E. Apelt - Bladesmith]

Mask off the tang if you don't want it etched and causing issues.

 

[A.McPherson]

As Stacy said you should mask it off, rust bluing does add a tiny bit to the surface.

I don't know if you've done rust bluing before or not, but I've done it a couple times with varying levels of success.

A couple super critical things:
1 Keep your dirty mitts off!! (Wear gloves and don't scratch your face while wearing them!)
2 heat your work piece up a lot more than you think you need to! (Not too hot to touch, but close). If you don't droplets of water will form as steam condenses on the work piece, and leaves a blotchy finish
3 polish the work to as high of a finish as you want BEFORE you blue it, or you're gonna have to start over and you'll hate your life more than a one legged man at an as$ kicking contest.