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Controling coloring of titanium


#1

How can I control the coloring of titanium and repeating? Is there is
any supplier/ tools for it?


#2
How can I control the coloring of titanium and repeating? Is there
is any supplier/ tools for it? 

What I’ve been taught is to control the color by experimenting with
(and recording) the voltage applied to the item, as it is withdrawn
from a trisodium phosphate bath. We used the anodizer sold by
Reactive Metals - http://www.reactivemetals.com

Lorraine


#3

http://www.reactivemetals.com/ with out question. They have been
doing it for decades and are nice people.

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand


#4

Lorraine, (my mother’s name, too!)

Bill Seeley, owner of Reactive Metals, will be doing a workshop here
at Whaley Studios in San Diego Nov. 13 and 14. If you are in area,
this should be a great workshop with lots of about
forming and coloring titanium and niobium. Bill will have plenty of
materials and equipment here for sale as well.

Jay Whaley


#5

As Lorainne said you can do it with a powerful transformer /
rectifier. Which is expensive and you would need to be doing a lot
to justify the cost. You can also get a reduced range of colours and
control the colour reasonably accurately in a kiln. You can get all
the temperatures (and the voltages) in Oppi Umtracht’s book. or on the
web. Or just clean up a piece of titanium and wash it in alcohol, dry
with a clean tissue and hold over a flame, experiment and practice.

David Cruickshank
jewellerydavidcruickshank.com.au


#6
Lorraine, (my mother's name, too!) Bill Seeley, owner of Reactive
Metals, will be doing a workshop here at Whaley Studios in San
Diego Nov. 13 and 14. 

Thank you, Jay. Your mother must be a wonderful person. :slight_smile:

It was King Hi Li who originally asked. I replied because I’ve taken
a class on this method at the Gem Cutter’s Guild in Baltimore.

Lorraine


#7

David, It does not take a powerful expensive transformer to anodize
titanium and niobium. 0-120VDC, 0-1AMP SMT Micro Anodizer, $235 is
not a lot of money in todays world. A 0-150 DC power supply in a
surplus store even less money. Or build your own from surplus
parts… essentially a Variac type transformer, full wave bridge and
an isolation transformer. Done, under $100. Now, if you want to do a
bicycle frame that would be another matter.

Heat coloring is fun, way hard to control. I started out with heat.
Was not long before I wanted to do something specific and repeat it.
Had to anodize.

Bill
Reactive Metals Studio, Inc


#8

You can do this by connecting batteries together in series.

It’s not an ideal solution and as the batteries wear down you lose
exactitude - but it will work.

If you just need a few pieces anodized then I think this is a very
sensible way to go and it’s comparatively cheap.


#9

Thanks for putting me right. Sorry if i misled anyone. I am happy to
hear that you can get 120v dc anodizer in US. I have been unable to
find anything in Australia of that type under $1000 US and all much
larger units than I would need.

David
jewellerydavidcruickshank.com.au


#10
Thanks for putting me right. Sorry if i misled anyone. I am happy
to hear that you can get 120v dc anodizer in US. I have been unable
to find anything in Australia of that type under $1000 US and all
much larger units than I would need. 

David, if you can find any business around that deal in surplus junk
electronics and electrical gear, go look there for old
autotransformers, also called variacs. These things are what used to
be used widely to control the dimming of things like theatrical
lighting, before that was mostly replaced by solid state controls.
The variacs of course, also are made smaller, but in surplus, it’s
common to find them about the same size as a 1/4 hp motor, usually
rated 10 or 15 amps. What these things do is take 110 volts input (or
220, for many of them), and with the turn of a dial, convert it to 0
to 130 volts (most allow a range of from zero to a bit more than the
input voltage. These are interesting transformers in that they don’t
have two seperate input and ouput windings, just one, with a variable
center tap. What that means is that they do NOT isolate the input
voltage from the output, but you can take care of that safety issue
at little cost. Anyway, with these things giving you variable AC
current, then find a few higher current diods or a full wave
rectifier bridge. Again, one can find them in surplus, but new from
the electronics parts crowd, they’re not that costly. Add to these, a
modestly large electrolytic capacitor to filter the output DC ripple,
and you can have a crude, but workable titanium coloring rectifier.
You can get fancier. An isolation transformer either on the input
gives you greater safety, but these can cost sometimes as much as
the variac itself. You can get safety too, with a so-called “dead
mans switch”, a large pushbutton switch arranged so you have to hold
it down under pressure to keep the circuit running. Pull your hand
away, or jerk it away such as if you get shock, and the power cuts.
You can also use more sophisticated ripple filtering. Add a large
resister to the capacitor, for better filtering (the cheapest high
amperage low resistance resister I’ve found is a big light bulb) If
you can find in surplus an old higher rated choke coil, you can get
an even more efficient filter.

Anyway. Look up circuits for simple power supplies and variac power
supplies. I expect you can get ideas from the web easily enough.
Finding that variac is the key part. Even new, a 10 amp one shouldn’t
be too much more than a hundred bucks.

And if you don’t mind working slowly, meaning a power supply that
does not put out lots of amps, but rather only small currents but
still in the fill variable voltage you need, you might investigate
the sort of small variable power supply that used to be used with
model railroad trains. Usually these put variable 0 to 12 volts on
the track, but a step up transformer with that would give you higher
voltages. The low currents you get would mean it would take some
time to reach the desired color, but that’s not always a bad thing.

And if you’re not that much of a tinkerer with thngs electronic, how
come you’re letting little things like a wee bit of ocean get in your
way? Bill Seeley would no doubt be happy to ship one of his fine
anodizers to you in Australia, and they’re worth every penny… Would
Australian customes charge you too much?

Peter Rowe


#11

Hi Peter, Thanks for the plug. We dozens of anodizer down under.
Easy to do.

The big power supply you describe would be great accept for the
size. There are smaller Variac type transformers about. A 10amp would
power a bath big enough to anodize a bike frame! A lot of power and
dangerously high amperage. Not to be played with lightly. We made a
very nice little one for years based on a 3 amp Staco variable
transformer and a #4314 full wave bridge. It should be noted that
reading the DC voltage output on these gets a bit dicey. The out put
is dirty DC and for a volt meter to actually predict the finale
voltage that the bath will see some smoothing is required. The need
is to smooth the voltage as it goes to the meter. The bath will take
care of itself.

Bill
Reactive Metals Studio, Inc


#12
David, if you can find any business around that deal in surplus
junk electronics and electrical gear, go look there for old
autotransformers, also called variacs. 

I made our own anodiser almost as Peter suggests. But I made it from
a new 240v variac transformer. We use some device on the power supply
that interrupts in the event of a short. I think it’s called a RDU or
some such. (RDI??) I forget now. Anyway it was deemed to be safer
than an isolation transformer.

Ruth uses the machine a lot, as she’s big on Ti and Nb. Bill and co
know us from way back when he came here and demonstrated anodising in
his own wine glass.

Anyway, for us the full 240v is useful, as a lot of Ruth’s favourite
colours appear at or above 110v.

The sauvignon blanc electrolyte is the biggest running cost.

:wink:

Brian

Brian Adam and Ruth Baird
Auckland
New Zealand
www.adam.co.nz


#13
Hi Peter, Thanks for the plug. We dozens of anodizer down under.
Easy to do. 

You’re welcome. Nice to see that I not only onee who needs to
prrroofread betterrr befur hitting sent… (grin)

The big power supply you describe would be great accept for the
size. There are smaller Variac type transformers about. A 10amp
would power a bath big enough to anodize a bike frame! 

Yes, I know. I mentioned those big ones simply because, at least ten
years ago, they seemed to be a lot more common in cheap surplus
electronics shops, for dirt cheap prices (I found a couple once in a
Salvation Army store for five bucks each…) The smaller 3 am Stako
variacs are more suited but I’ve not usually seen them at much of a
discount. Perhaps you have…

A lot of power and dangerously high amperage. Not to be played with
lightly. 

Again, correct. The higher amperage though, can be nice if you want
to use this for, say, electroplating or electroforming. Usually, one
then gets the higher amperage from a larger step down transformer, so
the output is 0-12 volts or something like that, but with these large
variacs, there’s no reason the variac can’t be fed by a smaller step
down. Again, saves money. No other reason. Oh, and a too-large variac
does have one advantage. The variacs have one main weak point, and
that seems to be the connection to the movable tap. Too high a
current through one, and those seem to be where they burn out. And
the old used surplus units sometimes blow out before they should. So
an oversized variac means you’ll blow the fuse first, instead of the
variac itself. As for dangerous amperage, at the voltages used for
anodizing titanium, a whole lot less amperage is also dangerous.
Doesn’t take much to kill at 140 volts. The smaller unit one might
make from a smaller variac needs just as much concern for safe
handling.

We made a very nice little one for years based on a 3 amp Staco
variable transformer and a #4314 full wave bridge. It should be
noted that reading the DC voltage output on these gets a bit dicey.
The out put is dirty DC and for a volt meter to actually predict
the finale voltage that the bath will see some smoothing is
required. The need is to smooth the voltage as it goes to the
meter. The bath will take care of itself. 

That’s why the capacitor (minimum) or a resistor/capacitor filter.
For a bath, of course you don’t need a filter, since as you say, the
ripple takes care of itself just with the nature of a bath. But with
good output filtering, less heating and potential burning would take
place in the case of a small bath or, in the use of brush anodizing
(questionable safety there, without an isolation transformer…)

You can help the whole issue of a meter by not using a digital
voltmeter. use the old analog dial meters, and the meter will show a
decently repeatable reading for any given setting. It’s the
mean/average, of course, not the peak voltage, but it’s reasonably
repeatable, so usable. With filtering, of course, it’s much better.
The main other issue to mention with a capacitor filter is that one
should use a fairly high value resister in parallel with the
capacitor to bleed off it’s charge when the circuit is turned off.
Again, a safety thing… As to accuracy of the meter for getting a
desired color, it’s simple enough to start with a slightly lower
voltage setting and increase it till you get the desired color. That
way, differences in current load won’t throw you off too much.

Now, with all that nonsense said, I’ll also say that while I used
one of my home built anodizers for many years, when I finally bought
a decent digitally controlled one (from Bill, of course), it was a
distinct improvement in safety, repeatability, and ease of use. I’ve
not used the old patched together one since, (actually I sold it last
year to a young hopefully up and coming artist who couldn’t yet
afford a commercial one). (another plug for Bill Seeley and Reactive
Metals. great folks to do business with, or to share dinner with at
a SNAG conference… :slight_smile: )

cheers
Peter