Homebrew PCBs

Hi guys,

Perhaps one of you chemistry guys knows what happened here.  While 
etching a board, I got to thinking about how the Ferric Chloride 
stains some metals (and wood, and other things) black.  Always one to 
try things, I dipped an aluminum bar in the stuff for a few seconds.

When I pulled it out, it had what appears to be rust scale on it like 
crazy!  I assume this to be bits of Copper and not rust, but I was 
wondering if someone could explain what happened there?  I don't think 
it was electrolysis - no electricty going through the mess.

Yet, somehow, the copper seemed to attract to the aluminum - it didn't 
stick though.  A rinse in water removed it quickly.  The aluminum did 
turn gray in color and not black like i had hoped - so it was a failed 
experiment.  But, it sure was interesting and raised a few questions!

Chris

there is no copper.
  :)))

lcdpublishing <lcdpublishing@...> wrote:
   I assume this to be bits of Copper and not rust, but I was 
wondering if someone could explain what happened there?  
		
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[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "lcdpublishing" <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, April 07, 2006 2:55 PM
Subject: [Homebrew_PCBs] Chemists? Ferric Chloride and Aluminum?


> Hi guys,
>
> Perhaps one of you chemistry guys knows what happened here.  While
> etching a board, I got to thinking about how the Ferric Chloride
> stains some metals (and wood, and other things) black.  Always one to
> try things, I dipped an aluminum bar in the stuff for a few seconds.
>
> When I pulled it out, it had what appears to be rust scale on it like
> crazy!  I assume this to be bits of Copper and not rust, but I was
> wondering if someone could explain what happened there?  I don't think
> it was electrolysis - no electricty going through the mess.
>
> Yet, somehow, the copper seemed to attract to the aluminum - it didn't
> stick though.  A rinse in water removed it quickly.  The aluminum did
> turn gray in color and not black like i had hoped - so it was a failed
> experiment.  But, it sure was interesting and raised a few questions!

You can get an electrolytic effect (a battery) by putting two dissimilar 
metals in an acid solution, and iron can be coated with copper just by 
putting it in copper sulphate solution: iron is dissolving and being 
replaced by copper. Perhaps that was happening in your case.

Leon 

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Don't know the actual chemistry, but what happened is the Ferric 
Chloride actually etched the aluminum at a VERY fast rate. If you 
dip the aluminum into room temp solution and leave it for a minute 
or so it will actually start the solution boiling against the 
aluminum the reaction is so fast. Plus the part will get hot. Was 
just playing with this yesterday after doing some research on 
etching aluminum. Dunked a 1/2" dia aluminum bar about 6" long with 
about 2" of the bar in the room temp etch. Within a minute the other 
end of the bar was getting noticably warm. Washed off the scale and 
scum and measured. About .008" of diameter was removed from the bar. 
The resulting gray is the etched surface of the metal.

Tim 
A2Z CNC 
1530 W Tufts Ave Unit B 
Englewood CO 80110 

tim@... 
www.A2ZCNC.com 

USA made accessories for desktop mills & lathes.

If you put some iron or steel in the CuCl it gets a copper coating.
I dunno what happens here, i expect it is some form of electroless plating.

But i think in your case something different is happening, since the CuCl  
copper coat on iron is thin and mostly smooth.

If you want to get the aluminum black you can anodize it and use black  
color with that. Seems quite easy to set up at home, although i didn't  
find enough need so far.

ST


On Fri, 07 Apr 2006 15:55:54 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

> Hi guys,
>
>
> Perhaps one of you chemistry guys knows what happened here.  While
>
> etching a board, I got to thinking about how the Ferric Chloride
>
> stains some metals (and wood, and other things) black.  Always one to
>
> try things, I dipped an aluminum bar in the stuff for a few seconds.
>
>
> When I pulled it out, it had what appears to be rust scale on it like
>
> crazy!  I assume this to be bits of Copper and not rust, but I was
>
> wondering if someone could explain what happened there?  I don't think
>
> it was electrolysis - no electricty going through the mess.
>
>
> Yet, somehow, the copper seemed to attract to the aluminum - it didn't
>
> stick though.  A rinse in water removed it quickly.  The aluminum did
>
> turn gray in color and not black like i had hoped - so it was a failed
>
> experiment.  But, it sure was interesting and raised a few questions!
>
>
> Chris

Hello Chris,

  Friday, April 7, 2006, 3:55:54 PM, you wrote:

> Hi guys,

> Perhaps one of you chemistry guys knows what happened here.  While 
> etching a board, I got to thinking about how the Ferric Chloride 
> stains some metals (and wood, and other things) black.  Always one to
> try things, I dipped an aluminum bar in the stuff for a few seconds.

> When I pulled it out, it had what appears to be rust scale on it like
> crazy!  I assume this to be bits of Copper and not rust, but I was 
> wondering if someone could explain what happened there?  I don't think
> it was electrolysis - no electricty going through the mess.

> Yet, somehow, the copper seemed to attract to the aluminum - it didn't
> stick though.  A rinse in water removed it quickly.  The aluminum did
> turn gray in color and not black like i had hoped - so it was a failed
> experiment.  But, it sure was interesting and raised a few questions!

> Chris



  You should try with some used Fe3Cl

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Please be advised what was said may be absolutely wrong, and hereby this disclaimer follows.  I reserve the right to be wrong and admit it in front of the entire world.



[Non-text portions of this message have been removed]

I had thought about getting into annodizing, but I got too many 
things going now.  I just thought i would give it a try - much to my 
surprise the strange things happened :-)




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> If you put some iron or steel in the CuCl it gets a copper coating.
> I dunno what happens here, i expect it is some form of electroless 
plating.
> 
> But i think in your case something different is happening, since 
the CuCl  
> copper coat on iron is thin and mostly smooth.
> 
> If you want to get the aluminum black you can anodize it and use 
black  
> color with that. Seems quite easy to set up at home, although i 
didn't  
> find enough need so far.
> 
> ST
> 
> 
> On Fri, 07 Apr 2006 15:55:54 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> > Hi guys,
> >
> >
> > Perhaps one of you chemistry guys knows what happened here.  
While
> >
> > etching a board, I got to thinking about how the Ferric Chloride
> >
> > stains some metals (and wood, and other things) black.  Always 
one to
> >
> > try things, I dipped an aluminum bar in the stuff for a few 
seconds.
> >
> >
> > When I pulled it out, it had what appears to be rust scale on it 
like
> >
> > crazy!  I assume this to be bits of Copper and not rust, but I 
was
> >
> > wondering if someone could explain what happened there?  I don't 
think
> >
> > it was electrolysis - no electricty going through the mess.
> >
> >
> > Yet, somehow, the copper seemed to attract to the aluminum - it 
didn't
> >
> > stick though.  A rinse in water removed it quickly.  The 
aluminum did
> >
> > turn gray in color and not black like i had hoped - so it was a 
failed
> >
> > experiment.  But, it sure was interesting and raised a few 
questions!

> >
> >
> > Chris
>

Just like what drives pretty much everything in this universe, entropy. 
The copper ions in solution are more electronegative than aluminum 
metal. As a result electrons are transfered from aluminum to the copper 
ions. The copper atoms become neutral (metal) and the aluminum atoms 
become ions (dissolved in solution).

Why is your experiment be a failure?. You clearly determined the answer 
to your question if ferric chloride can turn an aluminum surface black.

lcdpublishing wrote:

> Hi guys,
> 
> Perhaps one of you chemistry guys knows what happened here.  While 
> etching a board, I got to thinking about how the Ferric Chloride 
> stains some metals (and wood, and other things) black.  Always one to 
> try things, I dipped an aluminum bar in the stuff for a few seconds.
> 
> When I pulled it out, it had what appears to be rust scale on it like 
> crazy!  I assume this to be bits of Copper and not rust, but I was 
> wondering if someone could explain what happened there?  I don't think 
> it was electrolysis - no electricty going through the mess.
> 
> Yet, somehow, the copper seemed to attract to the aluminum - it didn't 
> stick though.  A rinse in water removed it quickly.  The aluminum did 
> turn gray in color and not black like i had hoped - so it was a failed 
> experiment.  But, it sure was interesting and raised a few questions!
> 
> Chris
> 
> 
> 
> 
> 
> 
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> 
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
>

Chemistry - strange stuff :-(

Yes, you are correct, it was not a failed experiment.  It just 
didn't give me the results I wanted - black. But, in reality, that 
isn't too much of a surprise - it was just a fleeting thought while 
bored :0

Thanks for the explanation though!  Chris


--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...> 
wrote:
>
> Just like what drives pretty much everything in this universe, 
entropy. 
> The copper ions in solution are more electronegative than aluminum 
> metal. As a result electrons are transfered from aluminum to the 
copper 
> ions. The copper atoms become neutral (metal) and the aluminum 
atoms 
> become ions (dissolved in solution).
> 
> Why is your experiment be a failure?. You clearly determined the 
answer 
> to your question if ferric chloride can turn an aluminum surface 
black.
> 
> lcdpublishing wrote:
> > Hi guys,
> > 
> > Perhaps one of you chemistry guys knows what happened here.  
While 
> > etching a board, I got to thinking about how the Ferric Chloride 
> > stains some metals (and wood, and other things) black.  Always 
one to 
> > try things, I dipped an aluminum bar in the stuff for a few 
seconds.
> > 
> > When I pulled it out, it had what appears to be rust scale on it 
like 
> > crazy!  I assume this to be bits of Copper and not rust, but I 
was 
> > wondering if someone could explain what happened there?  I don't 
think 
> > it was electrolysis - no electricty going through the mess.
> > 
> > Yet, somehow, the copper seemed to attract to the aluminum - it 
didn't 
> > stick though.  A rinse in water removed it quickly.  The 
aluminum did 
> > turn gray in color and not black like i had hoped - so it was a 
failed 
> > experiment.  But, it sure was interesting and raised a few 
questions!
> > 
> > Chris
> > 
> > 
> > 
> > 
> > 
> > 
> > Be sure to visit the group home and check for new Links, Files, 
and Photos:

> > http://groups.yahoo.com/group/Homebrew_PCBs
> > 
> > If Files or Photos are running short of space, post them here:
> > http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> > Yahoo! Groups Links
> > 
> > 
> > 
> >  
> > 
> > 
> > 
> >
>