Homebrew PCBs

As I understand it, the H2O2 is used to provide oxygen to the HCl, 
but using 3% peroxide slows it down because of dilution of the 
HCl.  Has anyone tried just bubbling some oxygen through the HCl? Or 
is this just too dangerous to contemplate?? Thought I'd ask before 
trying. <smile>

Mark

On 22/03/2010 18:35, Mark Lerman wrote:
> As I understand it, the H2O2 is used to provide oxygen to the HCl,
> but using 3% peroxide slows it down because of dilution of the
> HCl.  Has anyone tried just bubbling some oxygen through the HCl? Or
> is this just too dangerous to contemplate?? Thought I'd ask before
> trying.<smile>

It's not all that dangerous, but you won't get much, if any, 
oxidisation. H2O2 is needed.

Leon
-- 
Leon Heller
G1HSM

It's not oxyGEN you need, it's an oxiDIZER you need.  Bubbling oxygen 
through the solution can re-oxidize the chemicals that are there (such 
as with CuCl etchant), but oxygen alone isn't enough to work with plain HCl.

On Mon, 22 Mar 2010 14:35:42 -0400, you wrote:

>As I understand it, the H2O2 is used to provide oxygen to the HCl, 
>but using 3% peroxide slows it down because of dilution of the 
>HCl.  Has anyone tried just bubbling some oxygen through the HCl? Or 
>is this just too dangerous to contemplate?? Thought I'd ask before 
>trying. <smile>

Just bubble air.  IIRC, it will convert to CUCL soon enough.  That
will require air to work.

Harvey

>
>Mark
>
>

Has anyone tried just bubbling with O3 (ozone) ?
That might be a good alternative to too diluted H2O2 as ozone is a good oxidizer if I recall right.

$0.02

Jean-Paul

--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:

>
> It's not oxyGEN you need, it's an oxiDIZER you need.  Bubbling oxygen 
> through the solution can re-oxidize the chemicals that are there (such 
> as with CuCl etchant), but oxygen alone isn't enough to work with plain HCl.
>

Maybe a better source of oxygen is sodium perborate. A while back, I accidentally stumbled upon this site while searching the topic of PCB etching,

http://catmacey.wordpress.com/projects/making-pcbs-with-simple-tools/etching-the-board/

Note the statement, "It's the standard mix for sale here in Barcelona". I could not find any further reference to its use in PCB etching. I collected some notes on sodium perborate. Apparently it's widely used in non-chlorine bleach (e.g. OxiClean), but is in general considered a solid form of hydrogen peroxide. To wit:

(ref. forgotten source)

"Sodium perborate tetrahydrate is prepared by reaction of sodium 
borate with hydrogen peroxide. Sodium perborate releases back 
hydrogen peroxide, if dissolved in water. Its properties in 
aqueous solution are practically similar to those of a solution 
of hydrogen peroxide. Accordingly, sodium perborate is considered 
as a solid form of hydrogen peroxide used as a strong oxidizing 
agent in various industry including in detergent. In comparison 
with solution of hydrogen peroxide, solid form of sodium perborate 
compounds provide better conditions of stability and convenient 
handling. Sodium perborate monohydrate provides a high available 
oxygen content equivalent to 32% hydrogen peroxide - 50% more 
active oxygen than the same weight of sodium perborate tetrahydrate."

The common product is tetrahydrate and I bought 1 lb. from here,

http://www.soapgoods.com/Sodium-Perborate-TetraHydrate-p-772.html

I haven't tried it. I think you just make up a saturated solution for your hydrogen peroxide equivalent. I am still using the Edinburgh etch version of ferric chloride which incidentally is much faster than straight ferric chloride, but still nasty. When I use up my supply of this stuff, I am going to give CuCl a try with sodium perborate.

Baxter

--- In Homebrew_PCBs@yahoogroups.com, Mark Lerman <mlerman@...> wrote:
>
> As I understand it, the H2O2 is used to provide oxygen to the HCl, 
> but using 3% peroxide slows it down because of dilution of the 
> HCl.  Has anyone tried just bubbling some oxygen through the HCl? Or 
> is this just too dangerous to contemplate?? Thought I'd ask before 
> trying. <smile>
> 
> Mark
>
Air Bubbling works great.  I don't put peroxide in it anymore.  Sometimes add some HCL from time to time and sometime leave the lid off to reduce the level sometimes.  It does take a while for Air Bubbling to get it back to the nice bright Green.  I kept my tank on the back porch.  It etchs fine even when it was Cold outside.

Ben

--- In Homebrew_PCBs@yahoogroups.com, Harvey White <madyn@...> wrote:
>
> On Mon, 22 Mar 2010 14:35:42 -0400, you wrote:
> 
> >As I understand it, the H2O2 is used to provide oxygen to the HCl, 
> >but using 3% peroxide slows it down because of dilution of the 
> >HCl.  Has anyone tried just bubbling some oxygen through the HCl? Or 
> >is this just too dangerous to contemplate?? Thought I'd ask before 
> >trying. <smile>
> 
> Just bubble air.  IIRC, it will convert to CUCL soon enough.  That
> will require air to work.
> 
> Harvey
> 
> >
> >Mark
> >
> >
>
You have to get enough copper in it first, then air will work.

On 22/03/2010 22:04, Bip's wrote:
> Has anyone tried just bubbling with O3 (ozone) ?
> That might be a good alternative to too diluted H2O2 as ozone is a good oxidizer if I recall right.

Ozone is difficult to make, rather toxic, and won't work very well.

Leon
-- 
Leon Heller
G1HSM

--- In Homebrew_PCBs@yahoogroups.com, Leon Heller <leon355@...> wrote:
>
> On 22/03/2010 22:04, Bip's wrote:
> > Has anyone tried just bubbling with O3 (ozone) ?
> > That might be a good alternative to too diluted H2O2 as ozone is a good oxidizer if I recall right.
> 
> Ozone is difficult to make, rather toxic, and won't work very well.
> 
> Leon
> -- 


I can't speak for how well it would work, but ozone is not at all difficult to make. My hot tub has an ozonator in it, the device is nothing more than a quartz UV germicidal lamp and ballast mounted in an aluminum box with a barbed hose fitting on it. It runs during the filtration cycle and the ozone is drawn into the water with a venturi. The stuff is toxic, but dissipates and breaks down quickly.

> 
> I haven't tried it. I think you just make up a saturated solution for your hydrogen peroxide equivalent. I am still using the Edinburgh etch version of ferric chloride which incidentally is much faster than straight ferric chloride, but still nasty. When I use up my supply of this stuff, I am going to give CuCl a try with sodium perborate.
> 
>


One of the thingsI like about CuCl is that it is transparent enough to see what's happening without pulling the board out. It gets darker and darker as copper dissolves, but a teaspoon of H2O2 clears it right up. When I'm done etching I usually leave the air bubbler on while I drill and stuff the board and that re-oxidizes it some for the next use.

bebx2000 wrote: 
> Maybe a better source of oxygen is sodium perborate. A while back, I
> accidentally stumbled upon this site while searching the topic of PCB
> etching,

Thanks for posting this, I have seen this fast etchant for sale around
here too, and normally, because my curiosity i rush on finding what is
it made off, how it works and other sources for getting the same but
this time i guess am too busy and just forgot. 
The site has great pics and descriptions too. Easy nice etchant.

Time ago i search for other oxidizers sources from common household
things. I saw the 'oxy action' products for laundry cleaning, with 30%
sodium percarbonate, making it 10% hydrogen peroxide 20% sodium
carbonate and 70% of unknown, cheap but useless to try. Also saw a
swimming pool 'oxy choke' made of Potassium peroxymonosulfate (not
persulfate) not cheap or convincing to try. But the sodium perborate
seem a good solid option. I will search if i can find the sodium
perborate here too.

But for me is pure curiosity. My bubled CuCl works nice. And i even got
who offered me 90% (300vol) hydrogen peroxide for free. After many
threads here about concentrated oxidizers i wonder about the lack of
replies to this. Sodium perborate was pointed here once 5 years ago
without useful reply. It's available on ebay too.

Sim�o

On 23/03/2010 23:01, James wrote:
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Leon Heller<leon355@...>  wrote:
>>
>> On 22/03/2010 22:04, Bip's wrote:
>>> Has anyone tried just bubbling with O3 (ozone) ?
>>> That might be a good alternative to too diluted H2O2 as ozone is a good oxidizer if I recall right.
>>
>> Ozone is difficult to make, rather toxic, and won't work very well.
>>
>> Leon
>> --
>
>
> I can't speak for how well it would work, but ozone is not at all difficult to make. My hot tub has an ozonator in it, the device is nothing more than a quartz UV germicidal lamp and ballast mounted in an aluminum box with a barbed hose fitting on it. It runs during the filtration cycle and the ozone is drawn into the water with a venturi. The stuff is toxic, but dissipates and breaks down quickly.

It's difficult to make in quantity, that device is *very* inefficient. 
It's just as well, it would make you rather ill, otherwise.

Leon
-- 
Leon Heller
G1HSM

Just a hobby hacker here, not a chemist…

IIRC, 140F to become effective?. Wouldn’t this be a problem for this application?

I was going to try sodium perborate monohydrate, until I ran across that info. 

Thanks,

Roger

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Simao Cardoso
Sent: Tuesday, March 23, 2010 6:58 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: HCl Etchant Question

 

  

bebx2000 wrote: 
> Maybe a better source of oxygen is. A while back, I
> accidentally stumbled upon this site while searching the topic of PCB
> etching,

Thanks for posting this, I have seen this fast etchant for sale around
here too, and normally, because my curiosity i rush on finding what is
it made off, how it works and other sources for getting the same but
this time i guess am too busy and just forgot. 
The site has great pics and descriptions too. Easy nice etchant.

Time ago i search for other oxidizers sources from common household
things. I saw the 'oxy action' products for laundry cleaning, with 30%
sodium percarbonate, making it 10% hydrogen peroxide 20% sodium
carbonate and 70% of unknown, cheap but useless to try. Also saw a
swimming pool 'oxy choke' made of Potassium peroxymonosulfate (not
persulfate) not cheap or convincing to try. But the sodium perborate
seem a good solid option. I will search if i can find the sodium
perborate here too.

But for me is pure curiosity. My bubled CuCl works nice. And i even got
who offered me 90% (300vol) hydrogen peroxide for free. After many
threads here about concentrated oxidizers i wonder about the lack of
replies to this. Sodium perborate was pointed here once 5 years ago
without useful reply. It's available on ebay too.

Simão 





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

--- In Homebrew_PCBs@yahoogroups.com, "Roger Blair" <Roger.Blair@...> wrote:
>
> Just a hobby hacker here, not a chemist…
> 
> IIRC, 140F to become effective?. Wouldn’t this be a problem for this application?
> 
> I was going to try sodium perborate monohydrate, until I ran across that info. 
> 
> Thanks,
> 
> Roger


140F is not hard to achieve. I use a fish tank heater in the etching tank I built, I think I paid $3 for a bag of used aquarium accessories at a garage sale, there was the heater, a couple of air pumps, some tubing and other random bits. It will heat the etchant that hot no problem.