Hot bluing smooth rods

The rods I have are unplated mild steel, and though keeping them oiled provides a reasonable level of protection, I was considering some options on surface finishes. Having a background in firearms, I am considering hot bluing the rods.

Reasons I'm considering this:

1. I can do it myself without much cost or equipment.
2. Hot bluing is considered a fairly tough finish, as proven in the firearms industry.
3. Hot bluing is not considered to add appreciable thickness to the part.

Can anyone come up with a good reason why I should *not* do this? I'm an engineer, but my knowledge of materials chemistry is somewhat lacking.

Thanks!

I can't say I've ever tried hot bluing a rod in a mechanical device, but now I find myself asking why not? Especially if it is cheaper than stainless or nitriding. Of course, you will still have to keep it oiled.

I would suggest trying it on one part first, evaluate how well it works and holds up, and if it works then do all of the other parts.

>I can do it myself without much cost or equipment.

I've seen the price on Brownells cheap kit. You could by a lot of stainless smooth rod with that. Maybe you mean "rust bluing"? Maybe you plan to farm it out? Maybe you already have all the gear, and you mean "not much more cost or equipment beyond what I've already sunk"?

@criswilson10:

That's basically what I thought. Why not? Oiling would need to be done with just about any metal-based coating for smooth operation anyway, so why not get a little more help from the bluing.

@pica:

Brownells's kit is very expensive - you're 100% correct about that. However, it's entirely possible to mix the salts yourself, which is what I will try first. Another option is to buy just the Brownells salts and cleaner ($200) and use much cheaper options for the 2 necessary tanks (surplus ammo containers supposedly work great) and the heater (any propane burner). My research tells me that mixing my own salts will give me an 8/10 on quality, while the Brownells chemicals and my own tanks will give 9/10 or 10/10.

It could also be outsourced to a gunsmith. Something like some steel bars would not be too expensive since he won't have to do any special work like on complicated firearms components.