anyone using the circuit specialist 120VDC for annodizing?

PURPLEDC

PURPLEDC

Joined
Apr 4, 2007
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Im having serious issues with this thing. Im using a mixture of purified water and borax. Anything over 70 volts on larger pieces sends this power supply into a epileptic state. It switches from constant voltage to constant current and the voltage drops as soon as a large Ti piece hits the water. Im trying to anodize handles from a benchmade 42 balisong. I got good bronze, blues and light blue but when i tried going to the light purple higher on the voltage scale my anodizer started crappin out. Anyone got some ideas?
 
I built mine with a variable AC transformer and bridge rectifier. By putting in a DPDT switch I can use it for etching also. It also has a digital voltmeter.

Ebay is a good place to find used variable AC transformers.
 
I've used one from Circuit specialists for years. I don't know that its the same one as yours but I've never had anything come up with mine. In fact from the stand point of what I use it for its been flawless.

STR
 
STR said:
I've used one from Circuit specialists for years. I don't know that its the same one as yours but I've never had anything come up with mine. In fact from the stand point of what I use it for its been flawless.

STR
Click to expand...

Here is a link to the one im using. http://www.circuitspecialists.com/prod.itml/icOid/7859 its model number is CSI12001X. And like i said if i do anything over 70 volts and put a 42 handle in the water the voltage drops to 23 volts and I get a very uneven color of pink and yellow. What is the largest piece you have anodized with yours? I havent tried the paintbrush type method and am trying to just do a dipping bath. Care to give me any insight on how to properly use this thing? Id really appreciate any insight.
 
That is the exact same one I use. They've gone up in price. They were $99 when I bought mine.

I have anodized big and little pieces left and right for customers as well as myself. Whole knives, all of which you could see posted on my forums or in my blog. If the voltage drops and does not continue to got back to where you set it it sounds like there is some stainless on the piece you are anodizing like maybe a big stainless detent ball or maybe you are dipping it too deep and touching the alligator clip to the water which will do that also. You need an extension piece or a scrap hook of titanium to use in the alligator clip if you don't have one. Dipping the clip in the solution will corrode the clip and if any stainless screws or the detent are left in the parts they'll corrode as well as bring the voltage down sometimes preventing it from ever getting to where you are wanting it.

Also, if you are not using the multi-etch I'd seriously recommend it.

STR
 
Also, you don't want to touch your negative plate of whatever you are using for that. This can cause a drop if not shock the crap out of you should you not have gloves on. I hardly believe that would be the case because you'd know it. Wal-Mart sells some plastic mesh screen in the craft section which is good for a separator for the tank to keep things from touching. Thats what I use.

STR
 
well, the only thing stainless is my cathode which is about a two foot piece of threaded rod that has been bent into a spiral about one foot of 1/2" material is submersed at all times. The handles im trying to do are all Ti with all screws and hardware removed. And im using dip hooks and tongs made of TI wire from Halpern Titanium. and when im dipping the parts its only into the first inch of water. Im wondering if im saturating the water with too much borax. Ill admit in the past ive used enough borax to where it wont even dissolve all the way. Im gonna contact tech support tomorrow with circuit specialists. From what your telling me im doing most of the stuff right. I dont know if this could be a problem but i havent been using distilled water but rather just purified tap water. I wondering if there is heavy metals in it effecting the current in the water. Im gonna get some distilled tomorrow and try again with less borax. I havent got the multi-etch yet but I hear it can remove a buggered up anodizing which will be great for me since sanding these handles is a PITA. Thanks for your help.
 
I've found if I bead blast first, then etch the piece right after that for 30 seconds that I get nice bright colors. I use the TSP PH which is Phosphate Free sold by Reactive Metals and have had great results with it. Never used Borax so I can't tell you much about it. Dish soap for the dishwasher is common and some guys use industrial grade sewer cleaner with hydrochloric acid in it. Personally I like the TSP free stuff and etch combo. In my own experimentation I've learned a lot and basically widened both the brightness as well as the various shades of colors I get by keeping notes on what each voltage gives me depending on how it was finished.

For example I get more subdued colors with just bead blasting alone but bead blasting combined with etching really brings them out quite bright. Also, anything above 70 volts is quite difficult to get by just bead blasting alone. In most cases the colors after that limit get blotchy at best so the etch really does eliminate a lot of that hassle.

With the colors under 70v you can notice differences in how some colors look and again for example 15 volts with just bead blasting gives me a dark brown. With bead blasting and etching first and then using the same voltage it brings more of a copper tone to the color that you don't get with just bead blasting alone. Its hard to describe but it really does matter a lot after 70 volts. I can pretty much religiously get the colors I chose by bead blasting the part alone up to that magic number. After that its hit or miss as to what I get without that etch and even then if you don't etch right away after blasting you need to soak the part longer in the etch to get what you will get anodizing right after bead blasting and etching. In other words its best not to let the parts sit before you anodize. What I think happens is that the titanium oxidizes on its own the longer you leave it out.

Others may have different experiences but these are mine. I've also run into times where some colors are harder than others to duplicate. Another example of this is that although both the lock and non lock side of a frame lock are anodized at the same voltage and even prepped the same before hand they come out different shades of that color. This seems to be more an issue when the parts were cut from different sheets or where one is thin and one thick and stuff like that or when say I did one years ago and had someone send me a knife to re do the color on because it scratched in places. I've found in those cases that if you have one part that needs re-done you can do that one and not notice until you get it back on the knife together side by side with the rest of the parts that they no longer match so anymore I end up just as a general habit redoing the whole thing whether it all needs it or not. This way its all the same again in most cases. Sometimes though I still run into rare issues where slight differences occur especially when I anodize a pocket clip I made and it comes out the same color of course, but obviously lighter or darker or just off by some amount. All I can figure is there are slight differences in the alloy make up of one sheet of my stock of titanium vs another.

STR
 
Thanks alot man. Im gonna get the TSP and etching solution. From what ive seen alot of the colors im trying to get will be able to be had at a lower voltage if the pieces are etched. Thanks again
 
My cathode is bigger than anything I anodize by quite a bit as far as the surface area of it. I just grabbed a scrap piece of titanium. Many people use a stainless screen in the bottom of the tank or to the side separated by a layer of that plastic screening or some other such thing to shield it from physical contact with the anode so stainless will work for the negative wire to connect to. I just happened to have plenty of scrap titanium. It could be your rod is not big enough I guess but since I've not run into any issues as yours I don't know what to tell you. If it acts the way it does for something obviously smaller than the rod just like it does for something bigger I'd say its not the cause.

STR
 
Hrm.

For anyone else curious, I wrote up quite a bit on how anodizing occurs, and how to build an anodizer, in a couple posts on this thread here: http://www.bladeforums.com/forums/showthread.php?t=690293&page=2

But, troubleshooting time.

Okay, first, to describe what is occurring electrically...

Amps = Voltage / Resistance.

Amps is a result.

Your power supply can put out anywhere from 0-120 volts, and draw up to 1 amp max. You can see by the simple formula above, that the higher the voltage, the higher the amps. Double the voltage, you'll double the current.

The reason your voltage is suddenly plummeting, is because that power supply is only rated for 1A, and it has current control turned on. Current control is a bit sneaky, because, as you can see from the formula... current and voltage are chained together, and the only other piece is resistance, which isn't changing. So, to control current, the power supply actually controls voltage, internally.

Suppose you were trying to anodize using 100 volts, and your resistance was only 20 ohms.

Amps = Volts / Ohms
Amps = 100 / 20
Amps = 5.

Uh oh, your power supply can only support up to 1 amp max before it fries. So, what does it have to do? Internally, it has to ease back on the voltage, until it's drawing at most 1 amp. How much?

Max 1 amp = Volts / 20
Volts = 20.

Make sense?

So, the basic operation of you power supply goes like this:

1 - Tries to supply the voltage you set it to.
2 - As long as the amps are less than 1, it keeps it at that voltage.
3 - If the amps rise higher than 1, it drops the voltage to limit the current to 1 amp.

Now, you'll also notice, your power supply lets you *manually* control the current too. This just lets you set a different 'max' current.

So, for example, if you wanted to use constant current of 0.1 amp.. you could just set it to that, and then crank the voltage as high as it will go. It'll probably never end up at the max voltage because it would be constantly trying to smother it to keep the current no higher than what you set it to.

...

First thing to check, is that you didn't manually set it to max out at a lower current. If you set max current to 0.1 amps for example.. you'd be causing your voltage to die off much quicker than it was supposed to, to not exceed 0.1 amps.

If that doesn't work, the problem is that your circuit simple requires to draw more power than that power supply can put out, at that voltage. That is the only cause of the voltage dropping down like it is.

Now, there are a few things you could try to do differently:

1) Don't do a full dip. Note that the third variable in the equation is resistance. The more metal you submerge, the more "options" the electricity has to leak out, and less the resistance. So, try dipping just 1/4" of the end of the handle if you'd like. That would diagnose whether the issue is power supply related. If it anodizes to higher colors when only a little bit is dipped in, the chemical process is working, but the power supply is inadequate. At the very least, you can dunk 1/2 the metal at a time, which should perhaps double the amount of voltage you can give it before it maxes out the power supply. It doesn't matter which 1/2 way you dunk it.

2) Use less electrolyte. Why this works is a bit harder to explain. Basically, the titanium-oxide layer that forms when you anodize, resists electricity flow. So that is how you can build up an even coat, rather than just the electricity taking the shortest path. As it takes the shortest path, it builds up an oxide layer, and suddenly that's not the easiest path anymore. If this worked perfectly, amps would never be an issue, they would just mean that the reaction occurs slower, until every electrical "hole" is "patched" by an equally thick oxide layer.

However, some electricity always "leaks" out through the surface anyway, indefinitely, in a way that does not thicken the oxide layer. If your "leak" current is too high (too much surface area), there won't be anything left over to anodize the unanodized parts, or the less-anodized parts.

Part of what makes this an "easy" way for electricity to "leak" out, is how conductive the bath is. If the bath is really good at carrying electricity (lots of ions in solution), then there's going to be lots of leakage. Very low resistance. Very high current draw.

So, in some ways, you want the circuit to be poor. You want the electricity to have to hunt around and find the easiest way out, which is out the thinnest-anodized part of the metal, all over. Try starting with distilled water and just a pinch of TSP (or baking soda, or table salt, or whatever, it really doesn't matter).

However, you can also have too little. For example, if resistance to get to the other side of the bath is too high (picking ridiculous numbers):

Amps = Volts / Ohms
Amps = 100 / 1,000,000
Amps = 0.0001 .... very very tiny. So that's not any good either.

...

If you determined that a partial dip did not affect the highest color you could anodize to, then the problem is chemical.

There are many grades of Titanium, I don't know that Benchmade always used the same grade. I do know that different grades have different abilities to anodize. I also know that the higher voltage colors are sometimes not reachable without the surface of the titanium being etched first. Etching roughs it up, which gives more interference patterns, which is where anodizing color comes from.

Most etchants are dangerous, I suggest using the Multi-Etch from Reactive Metals Studio, which is kinda special. It also works for stripping the anodizing layer, if you screwed up and used too high a voltage.

...

So, there you go. Take that, and see what those tests determine for you, and that'll help me diagnose further.
 
thankyou very much for your response. Im gonna switch some things up and give it another go.
 
What he said is good science, have you tested the resistance of your anodizing bath?

if you know what voltage you need for your color, adjust your bath electrolyte to balance the resistance so you get the voltage you need

-Page
 
sunshadow said:
if you know what voltage you need for your color, adjust your bath electrolyte to balance the resistance so you get the voltage you need
Click to expand...

Doesn't work like that. You'll get meaningless numbers for the resistance until the circuit is active, for many different reasons, (and if you try to measure resistance while the circuit is active, you destroy your ohmmeter). In fact, this would be about the most misleading way of diagnosing anything.
 
A. Brett Schaller said:
What is the multi-etch?
Click to expand...

Its sold by Reactive Metals. All I can tell you is that the stuff works wonders for the colors you will be able to get. Its something I won't anodize without anymore.

STR
 
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