[jimmontg]

I haven't done this,but it may be worth experimenting with. It will only work with alloys that heat treat under 1700 degrees F as that is the melting point of brass (copper,tin, zinc). Take, let's say a knife made from O1 and brass plate before HT. The brushing method is about a thousandth, 0.001 of an inch thick btw.
If you have the ability to electroplate the knife to 0.004 it may be interesting to see the resulting product. A controlled atmosphere kiln would be a prerequisite for the endeavor. I'm sure somebody has tried it, so I am sure it isn't a feasible financial deal. I was just pointing out that if you wanted your knife to appear golden you could wire brush it while it's hot after temper. You could of course just simply electroplate it after it was finished, but it cost money to have somebody do that.

BTW, FYI CO2 is not used for a controlled atmosphere oven as it has carbon in it. Don't be tempted because it's cheaper than Argon which isn't all that much higher and Helium is much more expensive. Helium is actually a byproduct of natural gas production. Once it is released into the atmosphere helium escapes into space never to be recovered again. All of our helium comes from the ground, there is precious little of it in our atmosphere and it is gone tomorrow.

I'm way overeducated for my station of life. I know enough about most things, but usually just enough to be dangerous. LOL