Thread: Mirror Polish: Just For Looks?

Still haven't finished my first restore, but Santa brought me some things I needed to get the job done.

I started to wonder about etching the blade (with vinegar?) after polishing it. Why? The contrast between the honed edge and the dark blade might look cool. Additionally, I am a novice honer, and the contrast might help me during bevel creation.

But what happens when you etch a piece of steel? As I understand it, the etching agent dissolves the metal. At a microscopic level, the steel crystals or grains hold onto each other in a jumbled fashion, each oriented randomly. This causes the crystals to dissolve at different rates relative to each other, and the surface transforms from a smooth plane into a pitted, uneven one. Any light bouncing off this surface will be diffused or scattered, and the metal will appear darker.

Now, for the practical side of the question: Will it affect how well the blade resists corrosion? After shaving, a razor is covered with an array of potentially harmful chemicals in the form of water, soap, skin, hair, oil, and whatever else might have been on your face. If your razor has a mirror finish, this gunk merely rests atop the smooth plane of metal and is easily wiped or rinsed off. But is etched steel so easy to clean? Are the molecules of these "pollutants" small enough to fit into the pits of the etched surface? If so, will they evade my [conventional] efforts to cleanse the blade? And finally, if they do, will they cause the metal to corrode faster than it would if it was mirror finish and completely free of gunk?

Anybody with theories, advice, or experience, please chime in.

Originally Posted by MisterLewisR

....But what happens when you etch a piece of steel? As I understand it, the etching agent dissolves the metal. At a microscopic level, the steel crystals or grains hold onto each other in a jumbled fashion, each oriented randomly. This causes the crystals to dissolve at different rates relative to each other, and the surface transforms from a smooth plane into a pitted, uneven one. Any light bouncing off this surface will be diffused or scattered, and the metal will appear darker.

Now, for the practical side of the question: Will it affect how well the blade resists corrosion? After shaving, a razor is covered with an array of potentially harmful chemicals in the form of water, soap, skin, hair, oil, and whatever else might have been on your face. If your razor has a mirror finish, this gunk merely rests atop the smooth plane of metal and is easily wiped or rinsed off. But is etched steel so easy to clean? Are the molecules of these "pollutants" small enough to fit into the pits of the etched surface? If so, will they evade my [conventional] efforts to cleanse the blade? And finally, if they do, will they cause the metal to corrode faster than it would if it was mirror finish and completely free of gunk?

Anybody with theories, advice, or experience, please chime in.

Hmm, good questions. If you only want a grayish surface I'd suggest some warmed, not hot, apple cider vinegar. Although any vinegar should work. This is a weaker acid, so you won't have problems with overshooting the mark and finding you cut too deep.

It really will not take more than 30 seconds to achieve the "look" you want. Leaving it in over night will cause some serious pitting. But either way, you are leaving a fresh, non oxidized surface that will be more prone to rusting after the etch.

Neutralize the acid used with baking soda. I make a paste and rub it in thoroughly. This also helps clean the surface a bit as the BS is somewhat of a mild abrasive. You should have a satin look to the surface after this. I'd suggest considering using a cold gun bluing solution if you don't like the gray color. The blade will take on as deep a blue, nearly black if you want it, color as you wish to paint on. The bluing will cause oxidation of the surface. This leaves less places for oxygen to find a point to start rusting.

Now, you'll still have bright steel at the edge where you're honing, that will rust as easily as any other exposed non-oxidized steel.

Hope this helps.

Originally Posted by Mike Blue

I'd suggest considering using a cold gun bluing solution if you don't like the gray color. The blade will take on as deep a blue, nearly black if you want it, color as you wish to paint on. The bluing will cause oxidation of the surface. This leaves less places for oxygen to find a point to start rusting.


Hope this helps.

Mike, is there a certain cold bluing you prefer?
Thanks

Here's a link to a decent show and tell about four different solutions: GunTech : Cold Bluing Touch-Ups - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools

I buy locally at Gun Bluing Made Easy with Van's Instant Gun Blue! In the end they all work about the same and it comes down to the color you want and whether your choice will get you there.