Homebrew PCBs

Hello, everyone, 

I've got a question that comes with a quick back-story.

Last winter, I started etching with a batch of cupric chloride that I had made myself.  I was hoping to aerate it for a while for reuse, so I left the lid off the waste container and let it sit on the garage table.  Unfortunately, I left back to school about a week later, but thankfully my dad kindly covered it back up for me.  

Unfortunately, when I returned in the spring, I noticed that from that week with the lid off, the nearby power drill had developed a fine layer of brown rust on some of its exposed metal parts.  

In retrospect, I should've predicted this, but I didn't since we've all discussed aerating our solutions without any issues.  

In light of "the unintentional etch," has anyone else had this issue before?  Also, how are y'all aerating your solution to avoid this problem?  I can imagine that aerating near something like a computer for a week could be disastrous since the vents expose the metal inside.  

I'd really appreciate any thoughts/hints for "responsibly" aerating!

:)

Many thanks for your input!

On 27/05/12 12:39, poofjunior wrote:
> Hello, everyone,
>
> I've got a question that comes with a quick back-story.
>
> Last winter, I started etching with a batch of cupric chloride that I had
> made myself.  I was hoping to aerate it for a while for reuse, so I left the
> lid off the waste container and let it sit on the garage table.
> Unfortunately, I left back to school about a week later, but thankfully my
> dad kindly covered it back up for me.
>
> Unfortunately, when I returned in the spring, I noticed that from that week
> with the lid off, the nearby power drill had developed a fine layer of brown
> rust on some of its exposed metal parts.
>
> In retrospect, I should've predicted this, but I didn't since we've all
> discussed aerating our solutions without any issues.
>
> In light of "the unintentional etch," has anyone else had this issue before?
> Also, how are y'all aerating your solution to avoid this problem?  I can
> imagine that aerating near something like a computer for a week could be
> disastrous since the vents expose the metal inside.
>
> I'd really appreciate any thoughts/hints for "responsibly" aerating!

The only aeration i do is when my PCBs are etched in the running bubble etcher. 
After that, i cover the top of the tall tank with a piece of wood to stop the 
HCl vapours escaping and corroding surrounding metal objects. I put a bit more 
HCl in every couple of months.

On Sun, 27 May 2012 02:39:10 -0000, you wrote:

>Hello, everyone, 
>
>I've got a question that comes with a quick back-story.
>
>Last winter, I started etching with a batch of cupric chloride that I had made myself.  I was hoping to aerate it for a while for reuse, so I left the lid off the waste container and let it sit on the garage table.  Unfortunately, I left back to school about a week later, but thankfully my dad kindly covered it back up for me.  
>
>Unfortunately, when I returned in the spring, I noticed that from that week with the lid off, the nearby power drill had developed a fine layer of brown rust on some of its exposed metal parts.  

That's fumes from the HCL inside.
>
>In retrospect, I should've predicted this, but I didn't since we've all discussed aerating our solutions without any issues.  
>
>In light of "the unintentional etch," has anyone else had this issue before?  Also, how are y'all aerating your solution to avoid this problem?  I can imagine that aerating near something like a computer for a week could be disastrous since the vents expose the metal inside.  
>

Happens a little.

1) store it outside.  A cheap plastic yard seat has storage in the
bottom, so I'd leave it outside and away from things if at all
possible.

2) etch outside, always.  

3) if I run a batch of boards, depending on the etchant strength, it
takes perhaps 20 minutes/board.  I run multiple boards, 2 or 3 sides
at a time.  so it won't take that long.

Harvey

>I'd really appreciate any thoughts/hints for "responsibly" aerating!
>
>:)
>
>Many thanks for your input!

It also depends on the HCl concentration.
Only add just enough HCl for it to work.
I see no rusting since I do this and keep the tank covered.

ST

On Mon, May 28, 2012 at 4:32 PM, Harvey White <madyn@...> wrote:
> On Sun, 27 May 2012 02:39:10 -0000, you wrote:
>
>>Hello, everyone,
>>
>>I've got a question that comes with a quick back-story.
>>
>>Last winter, I started etching with a batch of cupric chloride that I had made myself.  I was hoping to aerate it for a while for reuse, so I left the lid off the waste container and let it sit on the garage table.  Unfortunately, I left back to school about a week later, but thankfully my dad kindly covered it back up for me.
>>
>>Unfortunately, when I returned in the spring, I noticed that from that week with the lid off, the nearby power drill had developed a fine layer of brown rust on some of its exposed metal parts.
>
> That's fumes from the HCL inside.
>>
>>In retrospect, I should've predicted this, but I didn't since we've all discussed aerating our solutions without any issues.
>>
>>In light of "the unintentional etch," has anyone else had this issue before?  Also, how are y'all aerating your solution to avoid this problem?  I can imagine that aerating near something like a computer for a week could be disastrous since the vents expose the metal inside.
>>
>
> Happens a little.
>
> 1) store it outside.  A cheap plastic yard seat has storage in the
> bottom, so I'd leave it outside and away from things if at all
> possible.
>
> 2) etch outside, always.
>
> 3) if I run a batch of boards, depending on the etchant strength, it
> takes perhaps 20 minutes/board.  I run multiple boards, 2 or 3 sides
> at a time.  so it won't take that long.
>
> Harvey
>
>>I'd really appreciate any thoughts/hints for "responsibly" aerating!
>>
>>:)
>>
>>Many thanks for your input!
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>

On 27/05/2012 12:39, poofjunior wrote:
>
> Hello, everyone,
>
> I've got a question that comes with a quick back-story.
>
> Last winter, I started etching with a batch of cupric chloride that I 
> had made myself. I was hoping to aerate it for a while for reuse, so I 
> left the lid off the waste container and let it sit on the garage 
> table. Unfortunately, I left back to school about a week later, but 
> thankfully my dad kindly covered it back up for me.
>
> Unfortunately, when I returned in the spring, I noticed that from that 
> week with the lid off, the nearby power drill had developed a fine 
> layer of brown rust on some of its exposed metal parts.
>
> In retrospect, I should've predicted this, but I didn't since we've 
> all discussed aerating our solutions without any issues.
>
> In light of "the unintentional etch," has anyone else had this issue 
> before? Also, how are y'all aerating your solution to avoid this 
> problem? I can imagine that aerating near something like a computer 
> for a week could be disastrous since the vents expose the metal inside.
>
> I'd really appreciate any thoughts/hints for "responsibly" aerating!
>
> :)
>
> Many thanks for your input!
>
Like others have said. Don't have too much acid. High acid will increase 
etch speed, but the consequences are fuming and corrosion as you are 
experiencing. Of course if there are splashes and micro droplets finding 
there way to surrounding items then unwanted corrosion is inevitable. If 
you ever had a fish tank with aerator and no cover, you may of found 
water splashing a foot radius or more.  The etching tank *must* be 
covered with a lid when bubbling. I have noting more than 3mm slit 
opening in the lid , just enough for the PCB, and even so there are 
splashes.


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

--- In Homebrew_PCBs@yahoogroups.com, "poofjunior" <seeifyoucanmeetme@...> wrote:
>
> Hello, everyone, 
> 
> I've got a question that comes with a quick back-story.
> 
> Last winter, I started etching with a batch of cupric chloride that I had made myself.  I was hoping to aerate it for a while for reuse, so I left the lid off the waste container and let it sit on the garage table.  Unfortunately, I left back to school about a week later, but thankfully my dad kindly covered it back up for me.  
> 
> Unfortunately, when I returned in the spring, I noticed that from that week with the lid off, the nearby power drill had developed a fine layer of brown rust on some of its exposed metal parts.  
> 
> In retrospect, I should've predicted this, but I didn't since we've all discussed aerating our solutions without any issues.  
> 
> In light of "the unintentional etch," has anyone else had this issue before?  Also, how are y'all aerating your solution to avoid this problem?  I can imagine that aerating near something like a computer for a week could be disastrous since the vents expose the metal inside.  
> 
> I'd really appreciate any thoughts/hints for "responsibly" aerating!
> 
> :)
> 
> Many thanks for your input!
>


Acid is incredibly nasty stuff, actually anything that will etch copper will also attack most other metals to some degree. Even stainless is easily rusted by HCl or Ferric Chloride.

Whenever I aerate the stuff I try to do it outside, or at the very least in a well ventilated area away from any metal objects. It is inevitable that you will get some vapor in the air.

> Like others have said. Don't have too much acid. High acid will increase 
> etch speed, but the consequences are fuming and corrosion as you are 
> experiencing. Of course if there are splashes and micro droplets finding 
> there way to surrounding items then unwanted corrosion is inevitable. If 
> you ever had a fish tank with aerator and no cover, you may of found 
> water splashing a foot radius or more.  The etching tank *must* be 
> covered with a lid when bubbling. I have noting more than 3mm slit 
> opening in the lid , just enough for the PCB, and even so there are 
> splashes.
> 

I lay down several layers of newspaper under my etching tank to catch the mist. If the tank is particularly full or foul weather forces me inside, I lay a paper towel across the top of the tank to keep most of the mist from getting out. 

When finished, I pour the etchant into a clearly labeled sealed plastic bottle for storage and rinse out the tank with baking soda water. Unless you etch a lot of boards on a regular basis, I highly recommend storing the etchant in something that can be tightly sealed. If the tank gets knocked over somehow you'll have a real mess on your hands.