Heat Anodizing Steel

[AbidTalwala]

Hello Fellow Members,

Another few question I had for all you guys out there who know more than I do. I see a lot of heat anodizing / heat coloring / heat bronzing / heat bluing of steel liners, steel screws, and steel pocket clips; what does this do to the strength of the steel? Any negatives or positives that result? Any insight, knowledge, and wisdom you guys can provide would be awesome.

Best regards,
Abid.

 

[Cereal_killer]

Not a knife part but watch this video.

Around here (in the knife world) it's much more common to see Ti heat colored, not steel. The video linked above is a vaporizer (e-cig) part but the technique is the same and the guy gives very ckear and detailed instructions.

Start on something big, not a screw, its harder to mess up and overheat. Overheat the part and it'll turn white, almost like the original color and unlike Ti which you can just sand down and try again its much harder to get steel to take the color a second time.

 

[Comeuppance]

I've spent a lot of time heat anodizing stainless steel. I have a butane torch. I have a lot of knives. I get bored.

Heat anodizing stainless steel can affect the heat treatment if you go too far. Never heat anodize a blade. I haven't had any problems with the liners and pocket clips I have heat anodized, but I never go past a bronze on the lockbar annodization. When you start getting into blues and purples, you're talking about heats that could reasonably tamper with the heat treatment of the steel.

I heat-anodized all of the hardware on my Cold Steel Tuff Lite and my Ontario Utilitac II. Notice that they are both cheap knives that are beaters by nature - if you're going to heat anodize a knife, remember that you might lose some potential lifetime on the knife and that all warranties are voided in the process. My Tuff Lite is one of the few knives I'm keeping in an upcoming purge and the Utilitac is going to a friend for free. I don't recommend heat anodizing locksides or pivot hardware (including the stop pin) unless it's a knife you're not too worried about.

Now that I have all of those warnings out of the way, some tips:

• Windex is your best friend. Heat anodization is an oxidization process, which means that oxygen has to get to the steel, which means the steel should be absolutely as clean and oil-and-residue-free as possible.
• You will always get the better color from higher polishes.
• Lighting is extremely important. Make sure that you have VERY good lighting when heat anodizing, as the brightness of the flame and the subtle nature of the color changes can make it difficult to tell if you've hit the color you're looking for.
• Windex again. Keep a small glass of it handy for the process. Once the color is reached, IMMEDIATELY dip it in the windex to both cool it down and clean the surface of soot from whatever heat source you have used.
• Stovetop anodizing, in my experience, is more hassle than reward. Electric stoves have surfaces that are not optimal for perfectly even anodizing, and the way they work tends to leave a pretty uneven and ugly finish - and you can't see the side being confronted with the most heat because it is, by necessity, face down on the stove.
• I'll say it again. Make sure there is NOTHING on the surface. No finger oil. No leftover water. Nothing. Bare and bone dry.
• Keep a close eye. Anodizing is easy if you want bronze, but if you want purple or blue you have to watch like a hawk. The temperature ranges that steel changes color at is super slim. It'll be bronze for a solid minute, and then it's PURPLEBLUERUINEDYOUMISSEDIT. Seconds count. Know where your cooling solution is. It should, again, be windex.
• Watch your fuel levels. If you're heat anodizing and not using a stove, chances are that you're burning fuel. Steel anodizes when it reaches a certain temperature. Thicker steels require more time being heated to reach that temperature. More time means more fuel. If you run out before you hit the temperature you wanted, the refueling time will almost definitely mean you'll have to start over - especially since you have to find a place to put a metal object that is so hot that it would instantly cause 3rd degree burns. Chances are, that go is a bust.