Anodizing Titanium

B

Brad Lilly

Moderator and Awards Boss
Hey guys

What is everyone doing for a power source for anodizing titanium? I was thinking a power source could be built but electrical stuff quickly goes over my head.
 
Brad,
Mine is the same brand as Stan's,only mine is the 3 amp version.
I don't think you could build one as controllable and reliable as these and save enough money to make it worthwhile.
 
wow, I never knew they made something like that at that price point. I use the old school variac but that has got to be more controllable voltage wise.
my problem with my variac is passing color ranges. IE.. going for bright gold, then a little more,little more, just a little..then DANG, going blue......
I might have to get one of those.
 
bladegrinder said:
.... going for bright gold, then a little more,little more, just a little..then DANG, going blue......
Click to expand...

Just a side note, as I'm interested in this subject too, I thought anodizing colors worked the opposite of heat coloring. Meaning this: in heat coloring as heat increases you get pale yellow, then straw then gold then brown then purple then blue etc. I thought with anodizing, as you increased voltage you got the purple/blue first then gold with higher voltage.

The above quote confused me a bit. But I've never anodized anything so I'm not sure. Does anyone know? Thanks.
 
With these machines you can dial in the voltage you want to the .10th of a volt and repeat it any time you like. The output voltage is what you dial in so if the input voltage changes,and it will, you can still dial the output,DC, voltage you desire.
 
Calvin - doesn't your power supply display amps as well as volts? Can you tell me the range of current that is normally used? Voltage range also please.

Thanks, Ken H>
 
Yes Ken,it shows the amps that the machine is pulling. The way I use this machine is, I dial in the voltage I want,lower the piece I am anodizing into the solution then turn on the output power. Watch the amperage spike then drop,when it stops dropping then I turn off the output power and remove my piece.
The most common colors I see anodized are bronze,gold and blue. Those colors will all fall below 30 volts. You can go as high as 120 volts with my machine and get many different colors,I think that Michael Walker must have done most of his anodizing in the higher voltages because of the colors that he achieved.
You don't set the amperage on this machine,it shows the amperage that is being drawn and a circut breaker will trip and automaticly reset if too much amperage is drawn,on my machine that is 3 amps. The bigger the surface area of the piece you are anodizing,the higher the amps will be. Like I said,the amperage will spike at first and then gradually drop as the oxidization builds up,when the amps stop dropping your done.
 
If anybody is planning on buying one of these power supplies....get the 3amp model. I purchased the less expensive one (1amp), and it is totally inadequate for anything larger then a pocket clip. I made several attempts to anodize frame lock scales....and the 1 amp machine would take 3-5 MINUTES to achieve the "dialed in" color. I actually gave that one away, and went back to my old home made anodizer, wich colors almost instantly.

Once you understand how anodizing works, there are a LOT of possibilities for various color combinations. (lower volts will not color over higher volts....this means that you can anodize at say 22 volts for blue, then selectively sand an area, then go over it will something less then 22 volts, and have different colors)

One of the techniques I use is to reverse the polarity, and clip the end off a Q-tip clamped into the negative alligator clip.....and use it like a paint brush. Something that I recommed doing is to create yourself a "color chart" with YOUR andodizer, and the solution YOU use. Use that aforementioned "Q-Tip" and start at 2 volts on your machine. wet the Q-tip and dap is on a piece of Ti.....and keep going until you've gone through the full range of volts on your machine (I went every 2 volts). I used a .050" piece of Ti, that was big enough to hold a "dot" of color through the full voltage range of my machine. It's a quick reference guide so when you want a given color, you simple dial that number of volts in, and then either dip your parts, or "brush" on the color.

As far as the colors go.... a picture is worth a thousand words: (numbers were cut in with my rotary tool. Numbers indicate the volts for each color)
 
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Replace most of Eds "amps" with "Volts"

Great idea on the color chart technique Ed.

I made a bunch of coupons, but this is better!
 
Fellhoelter said:
Replace most of Eds "amps" with "Volts"

Great idea on the color chart technique Ed.

I made a bunch of coupons, but this is better!
Click to expand...

Yep,it's volts not amps. I read Ed's post and didn't even pick up on that.
It's the different voltage that causes the different colors,the amps are what they are,depending on the voltage and size of the piece.
 
Thanks for covering my butt guys! Don't know why my brain was stuck on AMPS! :) Just replace every "amp" with "volts" LOL! I think because I was talking amps in the beginning, I just kept going with it......I went back and edited it to be correct. :)
 
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Is the reason people anodize and not heat color for uniformity?
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I'm guessing hear but I would say control and uniformity are the biggest things. Trying to heat something to exactly the same temperature over the entire object is not as easy as it sounds. Add to that it would be easy to over heat and ruin the colors you were looking for. I don't know about titanium but any other metal I have worked with it will move or warp with a surprisingly small amount of heat.
 
Along with the things Brad mentioned, durability with anodizing is much greater then heat coloring. Both have their place since anodizing is generally used on Titanium......and it doesn't work on "steel".
 
Here is a color chart I found with approximate voltages for color range:

DC voltage for Titanium Colors.jpg

Since I've never done any anodizing (yet) I have no idea if these color/voltages are even close, but should be a general guide.

Ken H>
 
J. Doyle said:
Just a side note, as I'm interested in this subject too, I thought anodizing colors worked the opposite of heat coloring. Meaning this: in heat coloring as heat increases you get pale yellow, then straw then gold then brown then purple then blue etc. I thought with anodizing, as you increased voltage you got the purple/blue first then gold with higher voltage.

The above quote confused me a bit. But I've never anodized anything so I'm not sure. Does anyone know? Thanks.
Click to expand...

You are correct. The purple blue come with lower voltage and the lighter blue to gold comes at higher voltage. Another thing is you can always go from a color in the lower voltage to a color in the higher voltage without re-polishing but the reverse is not true. Once you are back to bare metal the process starts again like new so if you do not achieve a color you desire its easy to keep going until you get it right. It is also important to not remove your parts to early but keep them in the acid bath until the reaction stops. The finishes on your parts are also important to the color! Not that it changes the reaction, but it drastically changes the "look" of reflected light off the parts which is how we see color anyway.
 
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Bone Arrowhead Adam said:
You are correct. The purple blue come with lower voltage and the lighter blue to gold comes at higher voltage. Another thing is you can always go from a color in the lower voltage to a color in the higher voltage without re-polishing but the reverse is not true. Once you are back to bare metal the process starts again like new so if you do not achieve a color you desire its easy to keep going until you get it right. It is also important to not remove your parts to early but keep them in the acid bath until the reaction stops. The finishes on your parts are also important to the color! Not that it changes the reaction, but it drastically changes the "look" of reflected light off the parts which is how we see color anyway.
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This is all good advice,but. Did you mean to say "acid bath"?,or was that just a slip up like Ed calling,volts,amps?
Because the anodizing solution is not acid,it's ,distilled water(I use distilled water that I collect from my air conditioner condensat line.) and trisodium phosphate or some other additive,sometimes I use borax,that will oxidize the titanium when the electrical current causes the oxygen molecules to break loose and adhere to the titanium.
 
KenH said:
Here is a color chart I found with approximate voltages for color range:

View attachment 51584

Since I've never done any anodizing (yet) I have no idea if these color/voltages are even close, but should be a general guide.

Ken H>
Click to expand...

Ken,
Yes,those are approximate,you will discover how approximate when you start doing your own anodizing. It's best to do your own color chart from your own machine and referr back to it when you want to duplicate a color.
 
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