parrucco
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How can i make a surface conductive without going mad or broke?
Hi, for some weeks I tried everything I can to make some wax and plastic small items's surfaces conductive. The truth is I failed every time.
I am not a chemist, but i like to read and play with chemicals.
I want to do this to make some art. Please be patient with my ignorance and presumption to tinker with this matters.
I need to achieve this to electroplate and/or electroform this objects with copper and/or nickel. I already can electroplate on metals with no
problem.
I've got a good lab power supply I can regulate to output from 0.1 to 30 volts and from 0.001 to 5 amps. Plus all containers, connectors, supports, an
entire setup.
I made copper acetate and nickel acetate solutions from distilled vinegar, deionized water and metals samples (copper wires and nickel electrodes for
welding).
I repeat, plating on metals is not a problem (various pieces of metal sheets, coins, scrap iron, keys etc.).
I can make the deposits shiny and thick (on metals).
But I need to plate wax, cloth, cardboard and other fragile materials for my artistic endeavours.
Here is a synthesis of the attempt I made, I used for every try the same rigid plastic strips as sample.
- I tried almost any "cold galvanizing paint" spray or brush applied (containing zinc powder, in theory) I can source locally. They are not
superficially conductive, they are not conductive below the surface, or inside. I can not measure any resistance or flow of current with my
multimeter. I even tried to make a substitution reaction immersing painted samples in copper sulfate (agricultural, seems clean but not reagent grade)
to make the surface covered in copper. Nada.
- I tried all metallic looking finish spray paint I have (just in case). As imagined, niet.
- I tried to apply graphite from a graphite pastel (tested conductive) in all imaginable methods to the strips and paper with no appreciable results.
The best was a conductivity of several hundred thousand ohms per millimeter.
- I tried to apply graphite in powder form (lubricant), mixing it with several type of paints or glues. No.
- I tried to apply magnetic photocopier toner as well. No.
- I can obtain very small amount of very fine copper powder mixing 2g of copper sulfate (agricultural) with 5g ascorbic acid in 200ml of boiling
deionized water. The dried powder seems conductive on paper. Mixed with any proportion of paints seems not. The quantities involved are so small I can
not make many test...
- I bought "graphit 33" a graphite based spray paint, the datasheet say it can be used for electroforming, but it not work for me. Too high
resistance. Also is very easy to detach from any smooth surface when immersed in water. By heating at 100° Celsius for an hour they say surface
conductivity will be better. Not applicable with wax, obviously. They say polished with a brush will make it better, but it is too delicate. With the
softest brushes it will be removed or ruined instantly.
- I see online many inks and paints based on silver, graphite, copper, alluminium or even gallium. I can not afford to buy them. Like 300 $ for 1
liter is VERY too much.
- I know silver nitrate with ammonia can do electroless silvering. But it is too costly.
- I started to hate graphite by frustration... I will like something like copper or nickel electroless deposits much more. Copper sulfate plus
hydrazine will make a copper mirror inside a container (plus heat). But I dont want to mess up with hydrazine (wich I can not buy, also).
Also, copper oxyde plus hydrogen gas (and much more heat) will make a copper mirror (at least on glass heated with a flame). I can make hydrogen gas
easily by electrolisys or reacting aluminium with lye, but i can not flame-heat wax...
- Solution based on palladium salts activators like used for pcb making are too costly. (I will be delighted if proven wrong...)
- I condidered vacuum deposition with one (or more) fridge or air conditioner pumps. I can build/hack something like that. I think the heat involved
will destroy my wax models.
In conclusion, sadly I am severely limited by my finances (starving hacker/artist? can be a definition), I can use only products available in stores
and I have to accomplish this. What a challenge eh?
Please enlight me with some ideas. I have accumulated several type of chemical reagents, like several common acids for example. I can make some salts.
I can make explosions and survive stronger and deafer. I can resist several other failings, buy I have to win.
Tips? Tricks? Encouragement?
[Edited on 12-2-2015 by parrucco]
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papaya
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try aluminium spray paint - a friend once had a success covering plastic with copper. also you say graphite has low conductivity - sure, but you must
provide electrical contact not in a single spot - take some metal mesh and cover that graphite paintet area and when there grows enough copper it will
get more conductive I guess. Don't treat what I said as coming from expert, no.
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aga
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Hmm.
Limited options, considering it's a wax.
Most things will not adhere to wax.
Why must it be electrically conductive for Art ?
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Marvin
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Dipping the item in glue then graphite powder is supposed to work well. You need to be patient and electroplate at low current density until the item
has an complete coating of metal, then you can up the current. I've seen leaves, as in from a tree, done this way.
Edit, thinking on it I have no idea what glue was used, obviously it needs to resist water when cured. Copper powder was the best, I found some at a
local paint shop but never tried it for this. It tarnished quickly in storage.
[Edited on 12-2-2015 by Marvin]
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jock88
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Deposited lead dioxide will make things conductive. LEAD MAKES GREAT PAINT.
http://oxidizing.typhoonguitars.com/chlorate/leaddiox/porous...
http://oxidizing.typhoonguitars.com/chlorate/leaddiox/plasti...
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smaerd
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DC Magnetron Sputtering a metal such as copper or aluminum onto it. That's the best way!
However, sputtering on wax isn't something I'd probably bother trying. There are things like conductive fabrics but jeese I'm not sure if there's a
super easy perfect way to go about this. If you find one it probably is worth a patent.
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WGTR
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| Quote: |
- I tried to apply graphite in powder form (lubricant), mixing it with several type of paints or glues. No.
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Three points here:
1. You didn't make it concentrated enough. Add as much as you think you need, and then add twice as much. It will be quite thick. It's easy to not
add enough.
2. You need more than one form of graphite. Powder is good for promoting surface conductivity, and flake graphite is good for promoting bulk
conductivity. A 50:50 mix of each is a good start. One doesn't work too well without the other.
3. Using the method from #2, I have made bulk conductive microcrystalline wax. Just stir the graphite into the melted wax. Letting it sit for a bit,
if a glossy layer of melted wax forms on top of the mix, not enough graphite has been added.
| Quote: |
- I bought "graphit 33" a graphite based spray paint, the datasheet say it can be used for electroforming, but it not work for me. Too high
resistance. Also is very easy to detach from any smooth surface when immersed in water. By heating at 100° Celsius for an hour they say surface
conductivity will be better. Not applicable with wax, obviously. They say polished with a brush will make it better, but it is too delicate. With the
softest brushes it will be removed or ruined instantly.
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Two more points:
1. A conductive graphite coating has too high a resistance to be directly electroformed. All of the copper will first plate out up near where the
electrical connection is for two related reasons. One, the bath is too conductive relative to the part resistance, and two, the overvoltage for
plating copper onto graphite is higher than that for plating copper onto copper. You must first "strike" the part. One way to do this, is to
electroplate with a very dilute plating bath, probably 0.01-0.1g/L of copper sulfate. If the copper still tends to plate only near the connection,
then dilute the bath and try again. The strike solution will practically be as clear as water. Once there is a thin, even layer of copper on the
part, then it will be easier to electroform it.
2. Think of your finger as the pencil, and the wax as the paper. The graphite powder has to be rubbed into the wax surface pretty vigorously, not
simply brushed on. It makes for messy fingers, but it works this way. Even with bulk conductive wax, it is a good idea to perform this step to
promote more even surface conductivity.
| Quote: |
- I can obtain very small amount of very fine copper powder mixing 2g of copper sulfate (agricultural) with 5g ascorbic acid in 200ml of boiling
deionized water. The dried powder seems conductive on paper. Mixed with any proportion of paints seems not. The quantities involved are so small I can
not make many test...
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Copper made this way very easily oxidizes in air. It may be conductive when you make it, but not for long...if you go back and check the copper that
you streaked on paper, I'll bet it will be non-conductive by now. This is why silver is normally used in metal inks.
| Quote: |
- I know silver nitrate with ammonia can do electroless silvering. But it is too costly.
- Solution based on palladium salts activators like used for pcb making are too costly. (I will be delighted if proven wrong...)
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Silver is only about $20/troy ounce, and it goes a long way.
Instead of palladium, some surfaces (glass, for example) can be activated with dilute stannous chloride. Silver will deposit faintly onto this from a
1g/L AgNO3 bath. This is enough silver to form a silver mirror on. Silver also catalyzes copper deposition from an electroless
copper/formaldehyde bath. A silver mirror gives more even results for copper deposition, but it seems to work to a certain extent even with only the
1g/L AgNO3 immersion step.
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BromicAcid
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I have seen a few threads come up concerning making conductive paints or coatings for one reason or another but decided to dredge up my own thread
from... well, eleven years ago:
http://www.sciencemadness.org/talk/viewthread.php?tid=1990
There is some good stuff in there regarding conductive coatings.
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Dr.Bob
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How about fulleranes mixed in the wax?
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Praxichys
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What about lost-wax casting?
You could cast it directly with copper, or cast from aluminum and plate it with copper.
Even easier, make a silicone mold of the wax model, melt the wax out, and fill it with a low-melting alloy. Pure tin melts at 450F, and there are
high-temp silicone molds that will withstand that temperature. You could also go for something like Wood's metal which melts at 158F, similar to wax
in melting point but completely conductive. Plate it after casting with whatever you wish.
Here is a range of 13 alloys at various cost which range from 117F to 338F:
http://www.rotometals.com/Low-Melting-Fusible-Alloys-s/21.ht...
Here is the first Google hit I got for castable silicone that works up to 500F when cured:
http://www.aeromarineproducts.com/high-temperature-silicone....
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parrucco
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Thanks all for the nice and informed support, and for not saying me (even if you tought it) I'm already both mad and broke (as per topic's title). You
rocks guys (and girls if any).
papaya: I will try aluminium spray paint, I will buy it from a local store in the next days and make you all know the results. The
problem with this spray cans is they not specify how much metal powder is in... I have to "sense it" by istinct and choose one or two brand based on
magical thinking, talking about science... OR, I can search for an online supplier with free shipping and copious datasheets...
aga: I need to electroplate etched (engraved) steel plates with copper, solder on it small electroformed non conductive objects (like
wax parts, decorations), and plate it all again with copper and nickel to make one unique object. If this process work I can also use this technique
(electroforming of non conductives) to make almost anything I have in mind out of metal. I can possibly melt the wax out of the copper/nickel shells
and cast tin or aluminium inside them.
Praxichys, suggested used lost-wax casting (see below), something I already do in a measure. But this system seem more versatile to me, better
surfaces and finer details can be achieved (theoretically).
Marvin: I see on internet everyone and theirs grandmas can electroform over graphite to make leafs and natural objects as pieces of
jewelry. No matter how I tried to emulate, shamefully copy, learn, experimented, tried, prayed... This not work for me. I started to hate graphite.
Even talking of carbon start to upset me now. And I'm made of carbon in a percentage! Shit.
jock88: Lead dioxide seems promising (and surprising as I read), but I think it is too toxic/dangerous to use on the kitchen table
(or anywhere?) without too much paranoia. I have to pass... Sorry.
smaerd: Magnetron Sputtering is something I desire to try someday, but for this particular application doesn't seem the right thing.
Like vacuum deposition the big problem is most objects of my interest can not withstands the vacuum/heat combination. Sorry.
WGTR: As you suggested I tried to make several strike test baths with your indicated amount of copper sulfate (on 1 liter of
deionized water) and the addition of a drop of sulfuric acid in another, and the addition of 1 gram of citric acid in another. Same result. Copper
will deposit preferentially on copper wire ignoring the rest of graphite if not for 0,5 mm around the wire. I've waited patiently. Nothing. I tried
also both to overvoltage and to keep normal plating settings.
You were right, my samples covered in copper powder are not conductive anymore.
Regarding copper powder, what do you think about a suspension of this powder in alcohol (to prevent oxydation of particles) with a small amount of
paint thinner in a magnetic stirrer (I've built one out of scrap, but it work wonder) with the parts to be made conductive first painted with plain
colored spray paint, then immersed and, in theory, covered by the fast moving particles in suspension adhering to the surface made sticky by the
thinner?
Or a chamber with the powder made in motion by a jet of compressed gas/air on a freshly painted object ("naturally" sticky)?
And, do you (or any other) know a method to precipitate tin out of a tin salt acqueous solution?
I can by electrolysis dissolve some pure tin I have as an electrode in water plus sodium chloride or sodium carbonate added. If I can precipitate tin
particles maybe they will resist more to oxydization than copper.
Regarding silver, I can in effect try to make silver nitrate out of small almost pure ingots (wich I can buy if I find this prices locally) with
nitric acid (which I have). I tried to make this with some cheap silver jewelry but I have failed refining the solution containing copper and god
knows what other. In effect silver seems the simple answer to all my problems, several reactions can give a silver mirror with it.
BromicAcid: I already read your thread weeks ago. It is there (I think) I've got the cold galvanization-paint-to-copper process
suggestion. Wich not worked, probably by the poor quality of the paints I've got. There are a bunch of interesting ideas in there...
Dr.Bob: Ahah, what about a conductive alien diamond teleporting itself in the quantum matrix of the wax to make it a sexy
superconductor? The chances of me getting fullerene in any amount are equally absurd, sadly. Or maybe I miss some important informations, wich can be.
Ok, it is almost sure. No, ok, it is sure.
Praxichys: As I mentioned above, this is a process I used with some results, but for the type of things I've to do now it is not the
right thing. Thin sections, small details, engravings, parts wich need to enclose glass or other things... I'm comfortable melting tin alloys, but as
a note high temp silicone gave me not very good results. Not for repeated casting. I think for a single-use mold a (very dry) plaster shell work best.
But the product you linked seems better, it is practically made for this application, not an hobby store ten dollars things like mine.
[Edited on 14-2-2015 by parrucco]
[Edited on 14-2-2015 by parrucco]
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huegene
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I am struggeling with the same problem.
Recently i stumbled upon a few promising methods.
Escalating to the more complex/dangerous i have in mind:
thermal decomposition of copper formate.
i really hope that this one works because decomposition yields only non hazardous chemicals
thermal decomposition of copper formate or acetate in glycerol
next chemical deposition of copper with hydrazine tartrate salts,
check https://www.google.com/patents/US2801935
this looks very promising but getting hydrazine tartrate salts may be a problem. I wonder if tartaric acid is able to hydrolyze acetone azine or MEK
azine (any insight from an experienced chemist is more then welcome because i kind of want to evade the next step)
next copper mirror via reducing copper acetate with hydrazine hydrate.
check https://www.youtube.com/watch?v=8KUl3h5DeiM
my last resort is to try (fasten your seat belts)
red P -> white P,
white P -> calcium hypophosphite,
(without starting a serious fire and or killing myself in the process)
calcium hypophosphite -> copper hypophosphite
thermal decomposition -> copper
all that only to have a convinient (cheap) way of through hole plating printed circuit boards
i believe to have seen a copper mirror post in the pretty pictures thread
http://www.sciencemadness.org/talk/viewthread.php?tid=14644&...
reducing tetramine copper with ascorbic acid, I am not sure, if that gives me a nice conductive layer to plate on.
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aga
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Simplest way to make a surface conductive is to use either aluminium, copper or gold foil and rub it onto the surface.
The surface of the substrate material might not be conductive, but the metal is.
There is no chemistry here.
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careysub
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Another material that should be in play here, along with the graphites, is chopped carbon fiber. Those fibers are much longer than graphite flakes and
should help create conductive paths.
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aga
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Seeing as it needs to be electroplated, all you really need is for the wax form to be electrically conductive.
How about 'wire glue' ?
http://www.ebay.co.uk/itm/Conductive-Wire-Glue-Paint-NO-Sold...
Dip the wax form in the 'glue' and it will coat it with a conductive film.
Being a semi-liquid, it will conform to all the fine details too.
Edit:
If Al casting is OK, why not make a mold using the wax form and refractory cement, then melt the wax out before casting ...
[Edited on 2-12-2015 by aga]
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Sulaiman
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A little random but it may be very useful place to start if very interested in conductive surfaces,
I have seen a masterpiece of conductive plating onto plastic,
(I assume that it was plated, thinking about it it may have been sprayed)
a particular model of Programmable Logic Controller that we have repaired a few times has a plastic case,
the rear casing is covered in a high gloss chrome-looking finish, which forms an RFI/EMC screen/shield which is 'earthed'.
Inside there are plug-in p.c.b. headers on the rear wall, nothing special, but
the bus 'wiring' looks to be the same as the overall coating (but matte finish) with spaces where the underlying plastic can be seen.
the plastic case is also a printed electrical interconnection bus backplane.
I do not remember any of the faults being related to the 'backplane'
It must have some problem because I've not seen it widely adopted.
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