I have made myself a good anodiser, with a good amp control, but I
have not found the best anodising solution for titanium.
Reactive metals speak about Tri Sodium Phosphate (Na3PO4) but this
is in the Netherlands not available, even not at the chemical
suppliers. It seem to be completely banned here. I have tried Sodium
Tio Phosphate (Na5P3O10), but the colours will not be very bright and
are fading if the object is longer in the solution at lower voltages.
It seem to be etching the titanium. Now there are subscriptions who
say Ammonium sulphate, Sulphuric acid solutions ect. can be used.
My question is who has experimented with several different chemicals
or mixtures and can advise me a good solution.
Bill Seally recommends a material called “TSP Not” I think this is
Sodium meta silicate. I think someone said it was sodium carbonate
(soda ash) but I would think it is not??? I’ll try to find out
more for you. Jesse
Martin In regard to the anodizing solution, I thing almost any ionic
(that is any acid, alkali or salts) will work. I took a class from
THE expert in the field, Bill Sealy (? spelling) who claims to have
use every thing from Coke Cola (has phosphoric acid) to white wine
(sulfites and tartarates). I have used pickle and TSP (TriSodium
Phosphate, Na3PO4 -xH2O) with good results. A couple of hints- I
have heard that Chlorine is bad for color development so avoide table
salts and other chlorides. I think that two other factors are at work
hear. Titanium will not give as rich a color as Niobium and Titanium
is so reactive that it will form a nastry clear oxide on a clean
surface which will also interfere with the development of good
colors. There are many grades of Ti out there, from CP
(commercially pure) to various alloys like 6-4 (6% Al, 4% Vanadium)
or 6-2-4-2 (Al, Sn, Zr, Moly), these alloys do not color as well.
The way I have use Ti is to clean the surface by washing and then by
sanding with a random orbital sander, being sure that the sand paper
is not coated with a dust release compounds, then using the metal
soon afterwards.
I would urge anyone to contact Bill Sealy at http://www.reactivemetals.com for more info. He has a great deal of
knowledge about this stuff and sells some sort of cleaner for the Ti
so that you do not need HF acid to pre-etch the metal to get good
colors.
I have made myself a good anodiser, with a good amp control
Titanium anodising requires control that is based on voltage
variability not amperage variability. Are you sure you have built the
correct power source?
Reactive metals speak about Tri Sodium Phosphate (Na3PO4) but
this is in the Netherlands not available,
‘Sugar soap’ is another (common) name. But we use dishwash. Mix up a
solution that uses about as much dishwash liquid as you would if you
were about to wash the dishes by hand in the kitchen sink. That’s
your electrolyte.
... but the colours will not be very bright and are fading if
the object is longer in the solution at lower voltages.
That’s titanium for you. Niobium produces brighter colours. However
I suspect you are using too high a voltage. Please tell us exactly
what voltages and amps you are using.
OK, here is my two cents worth=85 The electrolyte really does not
matter. Low sudsing detergent of any kind is a good choice. It wets
and cleans the surface. Literally anything that will carry
electrical current will work. The most important thing is surface
preparation. In rare cases have I seen Commercially Pure grades of
titanium produce a full color range without a chemical surface
prep.It can be Nitric/HF or our MultiEtch. No amount of sanding can
replace a chemically cleaned surface. Interestingly Grade #5,
referred to as 6/4 and its sister alloy 3/2.5 will often color the
full range with out a surface prep. Don’t know why! Anodizing
titanium is nearly always a pain in the arse. As soon as you think
everything is working right something will change. The next batch of
Ti will need totally different treatment. Niobium is expensive, but
in this case you get what you pay for. Ease of use, formability and
outstanding anodizing. Bill
Hello Brian and Ruth, and other advisers My power supply is based on
a variac (variable transformer) after this a rectifier, stabilizer
and a FET (field emitter transistor) controlled constant power
output. So I can control the voltage and the amps.
I was making some test plates coming from the higher voltage going
to lower voltage. On these plates I have made a polished, brushed and
an etched area. And I degreased before using. They say the lower
voltage will not change the oxide layer made by the higher voltage. It
was for me impossible to purchase the TPS and thought Sodium Tio
Phosphate (Na5P3O10), will do the same. This stuff seem to etch
second order colours form 50 to 80 volts. A colour made at 85 Volt
nice green, fades if I use 75 Volt Is this the reaction of this
chemical or something else? It seems to me that it does not make a
difference if I use a high power 1 Amp/Cm2 or 0.1 Amp/Cm2. The
literature says that the oxide layer made with higher voltage, will
work as an insulator on lower voltages. ( Also some insulation
layers in capacitors are made of titanium oxides) But in my test
solution the bubbles also come of the higher voltage areas. Does
this mean that the oxide layer breaks of? . Next week I will try some
different solutions and see what happens.
Niobium gives brighter colours, but in my opinion I should be able
to achieve these same bright colours in titanium. When I colour
titanium with a flame I get very strong and sharp colours. This is
what I will try to find with voltage colouring. But maybe I want to
much, but this is an aim.
At least thank everybody in answering and if I find a good way I
will share.
Howdy, While I am a beginner at titanium working myself, I have read
that almost any ionic solution could eb used to anodize titanium.
Jewelers pickle, phosphoric acid, and Even soft drinks! The TSP I
bought was found in the paint dept. of a large hardware store. It is
used for extensive cleaning in preparation for painting.
Another possibility I may try is a wash additive called (I think)
either sodium or maybe calcium percarbonate.
I am concerned you didn't mention etching the titanium before the
anodizing process or which alloy you’re using. I assume you did etch
but if not you should expect only pastel/low saturation colors.
Also, a heavy texture will display the colors better than a highly
polished surface. The info from www.reactivemetals.com will clarify
some of these issues in depth for you. Carl 1 Lucky Texan
I was making some test plates coming from the higher voltage
going to lower voltage.
Ahah! Try the other way round.
Start with low voltages, like 15vdc or 20vdc. Then saturate the
metal at that voltage. Depending on the size of the piece you might
get an even brown colour. Then raise voltage by a small bit, like 5
volts, and watch for the colour change. Saturate at that voltage for
an even coverage.
And so on. till you see the colour range as you raise the voltage.
Useful exercise: start with 10 pieces in the anodiser and colour
them all at the lowest useful voltage. Remove one as a sample then
raise the voltage for the remaining 9 till you get the next colour.
Remove one and do the next colour on the remaining 8, etc to get a
10-colour palette.
If you start with high (80 or so) volts you’ll rapidly anodise a
thick oxide layer that zooms through the afore-mentioned colour range
to the secondary or even tertiary range and they’ll look duller and
duller the higher you go in voltage. See sparks? That’s a too high
voltage.
What are you using as an anode to touch on the workpiece? Titanium?
Occasionally you’ll need to sand the end of this to remove the
anodised (insulating) layer on this for it to continue to have an
effect.
Bill Seely-- Since you are so generous as to give advise, let me
exploit you a little more, if I may-- I have been happily anodizing
titanium for quite a while, now (using the Reactive Metals anodizer,
without any problems). I prefer the subtler colors I get with
titanium, without a surface etch. Now, I have come across some old
tantalum–sheet, not foil. Your catalog no longer lists it, and my
book and internet searches have yielded no help. Can you tell me
what it can do, and how? Why don’t you market it anymore? Any info
would be helpful, Thanks! --Noel Bill Seeley seeley_bill@hotmail.com
Brian, I wish to differ withyou on this statement. "What are you
using as an anode to touch on the workpiece? Titanium?
Occasionally you'll need to sand the end of this to remove the
anodised (insulating) layer on this for it to continue to have an
effect."
We have used the same touch rods for many years and never cleaned a
one. In this case the current runs on the surface of the rod, not
through the middle. The theory behind multi strand wire relates to
the added surface area and the capability to carry more current.
Bill
Tantalum is a very soft element and forms easily. It anodises
beautifully. The dark colored metal produces extraordinary color.
Like the others in this family you can not solder it. We no longer
carry it because of the high cost. It takes a 50 pound order per item
to have it made to specification. It would take years to sell that
amount. Niobium is very close to it in nature and costs so much less
that it becomes the practical choice. Bill
Hello all, I have done some research on the Titanium oxide layers You
never have to sand the anode. It is trough that titanium oxide layers
in combination with some salts is a perfect insulator. However the
oxide layer is only very tight to chemicals and electrons in an
oxidizing environment.
Looking at atoms level there is always an exchange of atoms, metal
oxides and electrons. Mostly they go out and others take there place.
Did you know that even metals evaporate. But is so less that it can
not weighted, but it is there. (fundamental research).
At the anode there is an reducing (H+ gas) environment created with
the few atoms, molecules who are going out the anode. This reacting is
enough to let the electrons flow out of the metal. See it as if
micro,micro crack occur in the surface where the electrons can flow
out. At the moment you stop the power on the anode the surface is
closing up again and is metal corrosion resistant again.