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Rosco Bodine
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| Quote: | Originally posted by Xenoid
| Quote: | Originally posted by Rosco Bodine
The color of the TiH2 should be a duller darker gray as opposed to the light metallic gray silvery color of the
unhydrided Ti .
This could account for and explain Xenoids observation that the hydrided substrate "passivated" immediately , if the TiH2 more precisely "immuned"
layer
was behaving in the same way as a passivation layer .
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If the hydrided layer is a darker grey, then I never achieved a hydrided layer. Despite varying the conditions the treated surface remained the
silvery light metallic grey!
Regards, Xenoid |
If it didn't darken , then you were probably just happily generating hydrogen on the surface of the *real* passivation layer of oxide that was never
etched away 
Oh well , better luck next time 
[Edited on 30-11-2007 by Rosco Bodine]
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dann2
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Hello,
Got around to plating with Cobalt Oxide in Ti
Going on patent US 3,399,966 Examply 2. (exact ratio of Co to O unknown!!!)
240 grams of CoSO4:7H2O in 500ml of made up solution in a 500ml standard beaker.
Temperature is 43C
pH is 2.8 (it was 6.8 when I made up solution, added some Sulphuric but added too much).
Stirring with magnetic stirrer
Two Ti cathodes
The anode(s) are a strip of Ti 1.1cm by 8cm by 0.2cm thick.
Current is 3mA (approx.) per square cm.(about 4 volts accross electrodes).
63mA total current into anode.
First anode into tank was a freshly etched Ti strip. It was totally etched in hot HCl for
about one hour (lots of bubbles coming off Ti). No Oxide left what-so-ever.
Connected + before putting it into beaker. It passivated immediately, with current going
very low after about 10 to 15 sec.
Next up was a piece of totally etched Ti (same as above) that had been left sitting on the
bench for a few days (I just happened to have it lying around from my DTO'ing).
Connected + before putting anode into beaker.
Funny thing is, it is plating OK, or at least the current is staying steady. It has been going now for
about 50 minutes.
Will leave for eight hours.
How would you raise the pH of the Cobalt Sulphate tank?
Add some Co Carbonate?
Is sulphuric acid formed at the anode?, if so its a bit like the Pb Nitrate tank where Nitric is formed at the anode.
If I wanted to try a Co Chloride tank I can make Co Chloride easily from Ca Chloride + Co Sulphate (Ca Sulphate will ppt)
How might one make Co Nitrate from Co Sulphate?
The DTO'ed Ti strip that I am testing in NaCl solution is still going OK. It has run now for a
total of 40 hours. It received five coats (five bakes). Who needs LD, eh.
Still have not gotton around to wheeling out the Lead Nitrate tank................
Dann2
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Rosco Bodine
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| Quote: | Originally posted by dann2
How might one make Co Nitrate from Co Sulphate?
Dann2 |
Depends on what things you have on hand of course .
One likely way is to precipitate the Cobalt carbonate by adding a solution washing soda or perhaps baking soda .
Decant the byproduct sodium sulfate solution , add fresh water as a rinse and decant the rinse water .
Then you can use nitric acid to make the nitrate from the carbonate , CO2 effervescing as byproduct . This would be the cleanest and best method .
Or you would likely get it by adding an ammonium nitrate
solution to the cobalt carbonate and boiling , ammonia and CO2 being evolved as byproducts , leaving a cobalt nitrate solution . This would be a
cruder method as it may not go to completion , leaving some unreacted ammonium nitrate mixed with the cobalt nitrate. There's a possibilty here too
that it may not work because of a complex of ammonia and cobalt nitrate forming , and then decomposing to the oxide
as the end result .
Another less clean method than the first , which would involve more loss and purification would be to add calcium nitrate solution to the cobalt
sulfate solution , and filter out the byproduct plaster sludge , leaving an impure Cobalt nitrate solution .
[Edited on 1-12-2007 by Rosco Bodine]
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Xenoid
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| Quote: | Originally posted by dann2
How might one make Co Nitrate from Co Sulphate?
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Hi Dann2, I have had absolutely no success with Patent 3,399,966 nor with the hydriding process, I've tried all sorts of combinations!
We must be thinking along similar lines, I'm having a look at Patent 4,366,042 - the substituted cobalt spinel paper.
I am at this very moment making some cobalt nitrate by reacting some calcium nitrate with cobalt sulphate. One gets a pretty thick goopy result like
strawberry yoghurt, but I've put it through my pressure filter and I now have a nice red cobalt nitrate solution. This is the same process I used for
making manganese nitrate, but this time I'm going to concentrate and recrystallise it to get a purer product. I'm going to make some zinc nitrate by
the same process, and have a go at a simple zinc cobalt spinel coat on Ti.
Regards, Xenoid
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Rosco Bodine
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I still have confidence that what I suggested five months ago has validity .
I think the Co(NO3)2 will work as a first interface baked treatment . No recipe of multiple ingredients to foul up , or get complicated , but just
Cobalt nitrate painted on and baked .
The combination with Zinc nitrate is an evolution on the same process , but Cobalt nitrate alone was first reported to work acceptably well .
http://www.sciencemadness.org/talk/viewthread.php?goto=lastp...
And if a DTO composition is going atop that , I'd be trying the ammonium stannate - ammonium antimonate derived
from 95/5 solder , or perhaps the syrupy chlorides derived polymer mixture (with zero free HCl) .
I have some Ti rods ordered , and have cobalt carbonate on hand . Have to get some 95/5 and a few other things
like oxalic acid before I'll be set up to do it . Definitely have the power supply requirements covered , have three lab supplies (and counting) but
need some fixtures and clamps .
I also have a 7'' X 1" rectangular burner and a Zero max
adjustable slow speed rotisserie for doing some spray coating experiments . I have to improvise an insulated chuck for holding the end of the Ti rods
. Figure maybe
a hole saw a bit larger than the rod and wrap the rod with
woven fiberglass strip or muffler bandage to fill the space . Maybe slot the hole saw lengthwise each side and put a split halves 2 screw set collar
around it so it works like a mega sized pin vise , the fiberglass providing a thermal break with the hot rod .
I have so many different things going on with other business though that I stay backlogged on experiments
I plan to do , so anyone else feel free to have at it if
you have time .
[Edited on 1-12-2007 by Rosco Bodine]
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Xenoid
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A couple of points:
To remove the passivated coating on my Ti rods, I have been putting them in an electric drill press and spinning them whilst holding 100 grit garnet
paper around them. I do this for about 30 sec to 1 min. I then transfer them to a small measuring cylinder containing concentrated HCl (290g/L). The
surface then begins to generate H2 and the HCl is turning mauve, presumably due to TiCl3. I have found however that sometimes nothing happens, if I go
back to the drill and grind it again it is usually OK! This implies that the passivated layer really is quite thick and tough!
I just couldn't resist it so I tried a single coat of unpurified Co(NO3)2 on a Ti rod and heated with a hot air gun for about 10 mins at about 250 oC.
This produced a fairly crappy mess (needless to say) but much of the rod turned a purplish colour. Initially I thought this was just dried nitrate but
now I think it may have been a thin oxide (spinel) layer (similar to lens coatings). It wasn't changing much with time, so I let it cool and tried it
in a perchlorate cell (it was handy). The crappy bits dropped of immediately, but the purplish coat kept on running for about 15 mins. I am quite
impressed with this. Looks like some good experimenting ahead!
Regards, Xenoid
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Rosco Bodine
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Here's some more bits of information that may be useful .
The oxide layer on Ti is tough but definitely *not* thick .
It is transparent and almost immeasurably thin .
For example freshly etched Ti heated in air for one hour at 500 C forms a TiO2 layer less than 1 micron thickness , and it can be doped , even if
the dopant coating is not applied until the second baking *if* it something that can dissolve into that (sub) 1 micron layer .
1 micron = .001 mm = .000039 inch ,
( a bit over a third of one ten thousandth inch )
1 micron = 10,000 Angstroms
To compare with what is the thickness of passivation
oxide layer on unbaked Ti , look again at this information
dann2 posted earlier in the thread .
| Quote: |
From www.azom.com
____________________________________________
Oxide Film Growth
The oxide film formed on titanium at room temperature immediately after a clean surface is exposed to air is 12-16 Angstroms thick. After 70 days it
is about 50 Angstroms. It continues to grow slowly reaching a thickness of 80-90 Angstroms in 545 days and 250 Angstroms in four years.
The film growth is accelerated under strongly oxidizing conditions, such as heating in air, anodic polarization in an electrolyte or exposure to
oxidizing agents such as HNO3, CrO3 etc. The composition of this film varies from TiO2 at the surface to Ti2O3, to TiO at the metal interface.
Oxidizing conditions promote the formation of TiO2 so that in such environments the film is primarily TiO2. This film is transparent in its normal
thin configuration and not detectable by visual means.
A study of the corrosion resistance of titanium is basically a study of the properties of the oxide film. The oxide film on titanium is very stable
and is only attacked by a few substances, most notably, hydrofluoric acid. Titanium is capable of healing this film almost instantly in any
environment where a trace of moisture or oxygen is present because of its strong affinity for oxygen. Anhydrous conditions in the absence of a source
of oxygen should be avoided since the protective film may not be regenerated if damaged.
__________________________________________
Dann2 |
So before baking , the layer is *really thin* although
it is most definitely really tough material .
It is something like a very tough "stubborn stain " in so far as a "coating" goes .
And "staining" it with something else , staining the stain
as it were is what doping accomplishes .
Part of how this happens is because the very thin coating
has columnar wells in it , pores which extend almost down to the surface of the Ti metal substrate . You have seen color anodized aluminum , well
that is done by dye getting trapped in the pores .
Now suppose instead of dye , we used something that can conduct electricity and it reaches down deep into
the pores where there may be only one molecule thickness
of TiO2 , or that a reaction occurs there which changes
that thinnest molecular layer of TiO2 into something modified to conduct electricity better . Current flows right up through those "dopant filled
channels" that are like stalagtites suspended from the conductive layer above , reaching downward to the Ti metal floor , ( theoretically speaking
) It takes an electron microscope to see this stuff , and unfortunately , I
don't have one . So no picture requests , please
IIRC , it takes about 360 C to develop the cobalt nitrate .
With regards to the spinels and substituted spinels ,
too much heat leads to different materials , so they definitely can be overbaked as well as underbaked .
The bimetal spinels are tougher coatings than the
plain cobalt spinel . Zinc was the best of these IIRC .
Copper is another one that had good electrical properties ,
as an added bimetal with cobalt , and I'm reviewing
to see what was the deficiency there if any , for chemical resistance perhaps or some other factor that made it
not get much attention , as did the zinc bimetal with cobalt . I think there was just some summary statement
which said that of the several tested zinc was the preferred one , but others worked also , and they didn't give complete details on all the ones that
were tested ,
except for the one voltage reported for the copper and cobalt bimetal spinel .
In an electrolytic capacitor patent describing similar baked on coatings using a nitrate , it was a baked MnO2 coating ,
improved results were gotten by mixtures of the carbonate
at about 10% of the amount of the nitrate , using the carbonate as a thixotropic thickener . This same technique is possibly equally applicable to
other nitrate
precursors . Also the hydrated nitrate salts can be melted for application or suspended in water or other solvents , like acetone or alcohol , DMSO .
These things along with possible use of the carbonate provide some room for experimentation .
That "blue stuff" is probably the "good stuff" you are wanting .
Here's a thought , when you are sanding your spinning rod
of titanium in the drill press , try wet sanding it with glycerin
or ethylene glycol and then put it into an alcohol or acetone solution of the cobalt nitrate , see if any cobalt plates onto
it as the solvent cuts through the glycerin film . You might try
mineral oil as a wet sanding also as the Titanium may form
an alcoholate with the glycerin or glycol .
Anyway , the TiH2 schemes are for minimizing or eliminating
the development of any usual passivation layer , nipping that problem in the bud before it goes anywhere .
[Edited on 2-12-2007 by Rosco Bodine]
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Xenoid
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Rosco, do you ever get that sense of "deja vu" in this thread.
Regards, Xenoid
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jpsmith123
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| Quote: |
How might one make Co Nitrate from Co Sulphate?
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According to one of the handbooks I have, with regard to ethanol, CoSO4 is slightly soluble, Co(NO3)2 is very soluble, NaNO3 and KNO3 are slightly
soluble, and their sulfates are insoluble; so maybe reflux the CoSO4 with KNO3 or NaNO3 in alcohol?
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dann2
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Hello,
I have never read a patent yet where the end product (anode) was the vastly superior, long lasting, novel, better than enything before, etc etc.
Ti metal when placed in HCl (cold) and then the whole lot heated to hot, will not etch. I presume the oxide coat gets thicker and thicker as the
challenge increases. If you put the Ti into hot HCl it will etch ok. Or OK in cold HCl if sasndpapered
I placed a piece of freshly etched Ti into my 500C oven for about 10 minutes. I t turned an exquisite velvet like purple.
Very pretty to look at.
My Ti strip has plated with Cobalt Oxide OK. It is like No. 50 sandpaper. When viewed under microscope it is a mass of nodules and holes. Plated for
7.5 hours. Will try in perc hlorate cell.
Connot rub off coating. It is rather weird that freshly etched Ti passived but the etched stuff that sat around for some days plated OK.
Dann2
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dann2
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Hello,
From a thermodynamic (spelling ) point of view LD will oxidize Ti, therefor we
need an undercoat ( Pt, DTO).
Is Cobalt Oxide capable of oxidizing Ti?
dANN2
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Xenoid
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| Quote: | Originally posted by dann2
I have never read a patent yet where the end product (anode) was the vastly superior, long lasting, novel, better than enything before, etc etc.
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Surely you mean..... "I have never read a patent yet where the end product (anode) was NOT vastly superior, long lasting, novel, better than enything
before, etc etc."
I have concentrated my crude Co(NO3)2 solution, during this process some very fine colourless crystals kept forming. I repeatedly poured of the
supernatent liquid and continued concentrating to about 1/4 to 1/3 volume. The liquid is now a very dark bergundy colour, like a fine Australian red
wine. and largish red crystals have deposited on the bottom. I have left it
overnight in the fridge. I believe the earlier fine crystals were residual CaSO4 as it does have appreciable solubility.
Edit: Hmmmm.. on closer inspection the largish red crystals are actually agglomerations of finer crystals. But they are Co(NO3)2
Regards, Xenoid
[Edited on 2-12-2007 by Xenoid]
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Rosco Bodine
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| Quote: | Originally posted by dann2
Hello,
From a thermodynamic (spelling ) point of view LD will oxidize Ti, therefor we
need an undercoat ( Pt, DTO).
Is Cobalt Oxide capable of oxidizing Ti?
dANN2 |
Sure Co oxide is capable of oxidizing it , but that is what would form the bimetal spinel or other molecular compound
interface ( substituted perovskite ? CoTiO3 ? ) .
You are going to have some sort of boundary layer that
is an intermetallic compound , or a bimetal or trimetal spinel ,
regardless of what goes on top . And PbO2 can be plated directly onto a Ti substrate in a highly acidic electrolyte .
Anyway that boundary layer is a modified solid solution sort of mixed oxides interface , or a molecular compound , and it
doesn't continue to react once it has formed AFAIK , it is stable unless it is subjected to some sort of attack by a third party temperature or
chemical influence which would disrupt that stable condition . That is probably why whatever conductive interface is formed on the substrate , it is
then blanketed beneath a thicker working layer to protect that interface from permeation of materials which might attack it ,
but generally that would be something from the electrolyte itself , not the coating .
@ Xenoid ,
Yeah like Yogi Berra said , It's deja vu all over again
Regarding patents , yeah you never see the patent declaring
that after a lengthy and costly laboratory analysis which
bears out the worthlessness of the proposed invention ,
management has decided it is only reasonable to spend
yet more of the stockholders money to secure legal protection for the intellectual property work product that
is Soooo not worth a damn and Sooo going nowhere
BTW , acetone will probably purify the nitrate fine as IIRC
a 50% solution is possible for the cobalt nitrate hexahydrate
in acetone .
[Edited on 2-12-2007 by Rosco Bodine]
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Xenoid
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| Quote: | Originally posted by Xenoid
......but much of the rod turned a purplish colour. Initially I thought this was just dried nitrate but now I think it may have been a thin oxide
(spinel) layer (similar to lens coatings). It wasn't changing much with time..... |
Hmmm.. I have changed my mind on this after heating some of my purified Co(NO3)2 on a piece of metal, it dehydrates and turns an intense purplish
colour just before decomposing to brownish crud. Not sure why the nitrate coating lasted in the perchlorate cell, given how soluble it is especially.
I'm harvesting a bit more Co(NO3)2 from my solution, then I'm going to recrystallise it to ensure I'm starting with a pure product. I checked with a
chemical supplier here in NZ, Co(NO3)2 (lab grade) was NZ$104 for 100g + $32 postage  so this is well worth while!
Regards, Xenoid
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Xenoid
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| Quote: | Originally posted by Xenoid
Edit: Hmmmm.. on closer inspection the largish red crystals are actually agglomerations of finer crystals. But they are Co(NO3)2
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Errrr... No they aren't, they are still fine, fibrous CaSO4, when harvested, and the "juice" is squeezed out they are colourless. I have concentrated
the solution even more, it is very viscous and a dark concentrated red wine colour. I've put it in the fridge and several "chunky" looking crystals
are now forming. This stuff (Co(NO3)2) sure is soluble, (98g/100g water). The viscous liquid should be good for painting purposes though!
Edit: ... Damn! This is more dificult than I though, the whole volume of liquid has transformed into crystals. I guess all the water has been consumed
in forming the hexahydrate. I've redissolved it all and added a little more water, I'll see how it goes!
Regards, Xenoid
[Edited on 2-12-2007 by Xenoid]
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Rosco Bodine
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Xenoid , go back to next to last post on page 19 where Twospoons and I were talking about purification of the nitrate . There is a lower *Tri*hydrate
that comes out
first at a higher temperature , above 56 C and that may
facilitate separation . If you decant on cooling at say 60C and harvest those crystals having formed , it should be mostly the trihydrate .
This could be a "beaker buster" so evaporation in an open bowl on a water bath might be a good idea .
http://www.sciencemadness.org/talk/viewthread.php?tid=2465&a...
More deja vu Something I suggested way back sort of
goes along with the "wetsanding" of the spinning rod scenario . I had thought of mixing some valve grinding compound carborundum grit with cobalt
nitrate or chloride
made into a paste with alcohol or DMSO or glycerin ect.
and using the mixture as an abrasive on titanium , figuring
that wherever the oxide was abraded , the surface reaction
with the cobalt would occur , possibly resulting in an intermetallic interface . Coating and baking would then further develop it into the spinel .
This method could also be applied to hydrided Ti .
[Edited on 2-12-2007 by Rosco Bodine]
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Xenoid
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Guys!....Guys!........
It's early days, but this is looking really, really promising!
Unable to constrain myself with the excitement I brushed onto an etched Ti rod, a SINGLE coat of the supernatant, saturated Co(NO3)2 solution from my
crystallising pan. I shook of excess, and put it in my improvised, hot air gun oven. It was baked at about 350 oC for 10 mins. After cooling, (which
takes some time for a 9.5mm Ti rod) the surface had a dark-grey to black, velvety coating. It was a bit uneven in parts and smudged slightly when
rubbed with a finger. I put it in saturated NaCl solution (chlorate cell) and adjusted the current to about 50mA/cm^2 which was about 1 Amp. The
voltage was 3.6 volts, a small amount of black detritus is floating around, but the anode still appears to be in good condition. After 2 hours the
voltage has risen to 3.9 volts but now seems stable. Most importantly, I haven't seen any coating flaking off, it appears to be well bonded. I think
the small amount of black crud floating on the surface has come from the coating surface, where it was a bit thick.
I'm very impressed with this, given that it was a quick and dirty trial before attempting the real thing. It looks and behaves like a genuine MMO
anode.
I note the Patent does not actually mention the concentration of the solution to use, that's why I was trying out the saturated solution. In
retrospect it appears too strong and could probably be diluted by half to produce a more even coat, not to mention the additional 11 coats!
I will report back!
Regards, Xenoid
[Edited on 2-12-2007 by Xenoid]
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chloric1
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MMO
The true test will be week run in a 1 litre chlorate cell. If it holds up then there you go. Also, if this cobalt oxide is adherent, you can plate
in the cobat nitrate/sulfate bath to buid a more robust coating. Your next mission will be to plate this with lead dioxide or manganese dioxide.
Fellow molecular manipulator
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Rosco Bodine
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| Quote: | Originally posted by Xenoid
I'm very impressed with this, given that it was a quick and dirty trial before attempting the real thing. It looks and behaves like a genuine MMO
anode.
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Outstanding !  One coat only !
Hell , even I was figuring a minimum of three coats
would probably be needed . This is damn good news ,
I was beginning to feel snakebit on this whole deal
And with a bit of finesse with tuning whatever works ,
subsequent "wear coatings" to build thickness if needed ,
this thing ought to fly .
The bimetal spinels , with zinc , copper , and the cobalt ,
and the manganese - vanadium , or manganese - lead
combinations , along with a whole slew of other combinations could be workable also . DTO could go on top as a vitreous sealing layer over the spinel
, if the temperature isn't exceeded which trashes the spinel .
That could be a workaround for the whole bugaboo that
involves getting a good conductive interface with the DTO ,
letting the spinel take that task . You could even come back on top of the DTO with more spinel as a catalytic baked on coating built up to a good
wearing thickness , and maybe never have to electrodeposit anything as a coating .
[Edited on 2-12-2007 by Rosco Bodine]
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jpsmith123
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Xenoid my first sample ran for a little while, then, shortly after I noticed some black stuff floating around, I took it out of the brine and wiped
it, and that's when it all came off.
BTW I was wondering about trying to improvise a furnace somehow using a heat gun. How did you rig up your improvised furnace?
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Xenoid
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| Quote: | Originally posted by jpsmith123
Xenoid my first sample ran for a little while, then, shortly after I noticed some black stuff floating around, I took it out of the brine and wiped
it, and that's when it all came off.
BTW I was wondering about trying to improvise a furnace somehow using a heat gun. How did you rig up your improvised furnace? |
Killjoy...
No, I've got a good feeling about this, given what a crappy effort I put into the coat. It's been going for 4 hours now, most of the black stuff
appeared in the first 1/2 hour.
I've got a Black & Decker hot air gun that can sit upright on a built in stand. I fit an ~5cm x 300mm Al tube on top in a vertical orientation, so
the air is blowing upwards. About 1/3 the way up the tube I drilled a small hole for a thermocouple so I could measure temperature. On the top of the
tube I've got a bit of Al with lots of holes in it to act as a baffle to slow the air flow down a bit. The bottom of the Ti rod sits on the slots of
the air gun and the Al tube is fitted over, so the rod is sitting at an upright angle. Make sure the end of the thermocouple is in free air and not
touching the Al tube or you will get a false reading.
I was going to say I saw an old toaster mini oven at a recycling centre the other day. I think I'll pick it up and fix/modify it. The hot air gun
method is very cumbersome and the temperature control is not very good. In particular there is a big temperature gradient, probably 50 oC or more,
between the bottom of the rod and the top, thats partly why I'm surprised this coating is holding up so well!
I'm starting to wish I hadn't wasted all that time trying to bake MnO2 coats onto gouging rods several months back.
Regards, Xenoid
[Edited on 2-12-2007 by Xenoid]
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Twospoons
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You'll find temperature control in a toaster oven to be a lot worse. The thermostats in those things are ghastly. You'd do better to work on your
hot-air gun - e.g. use a steel tube, wrap it in fibreglass wool, add thermocouples top and bottom, add a flow control baffle to the inlet of the
hot-air gun as a temperature control (caution required!) - or use a variac to control the heater (better). You should be able to get a nice steady
flow of constant temperature air, vs 40C of thermal cycling in an oven.
Helicopter: "helico" -> spiral, "pter" -> with wings
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dann2
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Hello,
About ovens, mine consists of a nichrome wire hung in a box made from domestic tyles surrounded by perlite and the whole lot wrapped in fiber glass
(roof insulation). The heater is 'controlled' with a variac, in other words it is not controlled. The oven holds the correct temp. when the variac is
set a a certain voltage. A clamp meter on the ac input lets you keep an eye on curretn going into heater if you so wish. It takes the oven about 4
hours to warm up and stablaize.
The toster should work OK if you have a variac and take out the toster controller yoke. Remove anything that is liable to go on fire (wire with
plastic insulation) and wrap the lot in fiber glass. If you only need to go to 350C fiber glass shoud stick that. You need to go to clost to 500 if
doing DTO.
The heat gun is more universal though!
Not having much luck with the Co plating stuff:
I tried out my Cobalt Oxide on bare Ti anode. It passivated within about one minute.
Current density was 100mA per square cm.
700g per liter Sodium Chlorate (Perchlorate cell).
Large quantity of bubbles came off of anode while it drew current.
The Cobalt oxide was completely stripped off the Ti at the surface of the liquid. There is a gold colour on
the Ti where the stripping took place, (Co metal ?). It is quite possible that the gold colour is there all
the time and when Oxide was stripped away cleanly the gold showed. I thing I can see gold color when
I scrape off Oxide with needle.
There is black suspended solid in jar due to this
Oxide stripping.
Coated a DTO on Ti strip with Cobalt Oxide. Similar set up as to last try on bare Ti.
It coatd OK. I only coated for 3 hours as the pH was getting very low (1.7) and I was afraid
the coating would start to strip off (or some such) so I stopped it. Looks similar to last attempt under microscope, just thinner.
Put it into Perchlorate cell. It is going OK. Large quantity of bubbles coming off anode. Black scum appearing on liquid surface.
It has been going for about one hour, no sign of any Perchlorate .............yet???????
Put DTO on Ti strip into Perchlorate cell to see how DTO would hold up in a Perc. cell.
It has already done 56 hours in a NaCl solution.
Dann2
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jpsmith123
National Hazard
Posts: 764
Registered: 24-6-2005
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How hot can a toaster oven get? I didn't think they would go much over 250 degrees C, which is probably not enough.
Anyway, my latest experimental anode is in the plating tank right now, and it has behaved differently from its predecessors. This one seems much
better, electrically, so far. Unfortunately, somewhere along the line I mixed up my array of Ti samples and I'm sorry to say I don't know how this
particular piece was prepared. It'll be my luck that this one will work very nicely and I won't be able to duplicate it.
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Xenoid
National Hazard
Posts: 775
Registered: 14-6-2007
Location: Springs Junction, New Zealand
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Toaster Oven
I said fix/MODIFY ....
I'm thinking about adding extra elements, fitting a thermocouple feedback triac energy controller and maybe a small metal fan on a metal shaft driven
from outside!
Cobalt spinel coated rod still stable after 5 hours...
I'm wondering if a new thread should be started for cobalt oxide coated anodes, as Rosco points out there is a lot of scope for experimentation here.
It's getting a bit removed from LDO anodes and this thread is getting too long!
Regards, Xenoid
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