Homebrew PCBs

I'm about to start using CuCl for etchant and was wondering if a 
plastic container marked "HDPE" (and a "2") would be suitable for 
doing the etching. The plastic is fairly thin but I plan to brace it 
with a frame around it.

I'd want to store the etchant in the container for an extended period 
of time with some sort of a lid. 

Any thoughts or suggestions as to how well this type of plastic would 
stand up to the CuCl?

Thanks, Bob

On Tue, 23 Aug 2005 05:44:36 +0200, Bob_xyz <bob_barr@...> wrote:

> I'm about to start using CuCl for etchant and was wondering if a
> plastic container marked "HDPE" (and a "2") would be suitable for
> doing the etching. The plastic is fairly thin but I plan to brace it
> with a frame around it.
> I'd want to store the etchant in the container for an extended period
> of time with some sort of a lid.
> Any thoughts or suggestions as to how well this type of plastic would
> stand up to the CuCl?
> Thanks, Bob


I keep HCl 30% in HDPE bottles, and after a few years there is a salt on  
the outside.
CuCl was kept in a PET bottle, salts on the outside too, quicker.

ST

Hi - HDPE = High Density Polyethylene. In general, this  is a long chain 
saturated (viz., no double bonds) chain of carbon and hydrogen and is very 
inert.  Chances are it will do just fine - we store hydrofluoric acid, which 
will attack glass, in these containers.

However, the salt formation has me a bit puzzled - where did this form - all 
over the container or around the lid?

Bruce
PS:  I am a chemist in my real life.
----- Original Message ----- 

From: "Bob_xyz" <bob_barr@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, August 22, 2005 11:44 PM
Subject: [Homebrew_PCBs] HDPE container for CuCl etching?


> I'm about to start using CuCl for etchant and was wondering if a
> plastic container marked "HDPE" (and a "2") would be suitable for
> doing the etching. The plastic is fairly thin but I plan to brace it
> with a frame around it.
>
> I'd want to store the etchant in the container for an extended period
> of time with some sort of a lid.
>
> Any thoughts or suggestions as to how well this type of plastic would
> stand up to the CuCl?
>
> Thanks, Bob
>
>
>
>
>
>
> 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
>
>
>
>
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>
>
>

On Tue, 23 Aug 2005 12:08:57 +0200, bdl7431 <bdl7431@...> wrote:

> However, the salt formation has me a bit puzzled - where did this form -  
> all
> over the container or around the lid?
> Bruce
> PS:  I am a chemist in my real life.


It has me puzzled too.
Not around the lid, all over the bottle, under and maybe also above liquid  
level inside.
Also, the HCl bottle appeared to get small protruding dimples after  
several years, which is why i hadn't refilled it last time but instead got  
a new one.

I have no idea what the salt is, i am only guessing it is salt. It's a  
white powder and somewhow it feels like a very fine salt to the touch.
My workaround (to prevent getting it on my fingers) was to cut off a  
larger bottle and use it as a sleeve around the bottle. Also, i found if i  
keep the HCl bottle really close to spray cans this isn't good, as they  
will rust at the seam. Note that the lids on those bottles are very  
reliable, i'm sure the acid traces came "through" the bottle.

Those are the standard-issue bottles at my chemicals store, so i use them  
for lots of stuff and don't see this problem with anything else, only with  
white spirit there was a problem too, it evaporated throught the bottle in  
an amount that would cause it to deform inwards, i use a glass bottle for  
that now. I am surprised petrol doesn't evaporate through jerry cans then,  
maybe those are PP and not PE, no sure. Haven't observed any contraction  
of the can with those.

I would look forward to any guesses you might have as to what this salt  
might be, i've tried to find out but nobody came up with an explanation so  
far.

ST

Bruce and Stefan - Thanks for your replies. It sounds like I'm good
to go with the HDPE.


Regards, Bob


--- In Homebrew_PCBs@yahoogroups.com, "bdl7431" <bdl7431@s...> wrote:
> Hi - HDPE = High Density Polyethylene. In general, this  is a long 
chain 
> saturated (viz., no double bonds) chain of carbon and hydrogen and 
is very 
> inert.  Chances are it will do just fine - we store hydrofluoric 
<snip>

On Wed, 24 Aug 2005 04:50:04 +0200, Bob_xyz <bob_barr@...> wrote:

> Bruce and Stefan - Thanks for your replies. It sounds like I'm good
> to go with the HDPE.
> Regards, Bob


Short term - certainly.
Long term - probably. Especially if you can live with it not looking so  
nice and put it in a try or something to catch the mysterious deposits on  
the outside.
I didn't notice any significant structural problems, like it going brittle  
or anything.

ST

Stefan Trethan wrote:

> On Wed, 24 Aug 2005 04:50:04 +0200, Bob_xyz <bob_barr@...> wrote:
> 
> 
>>Bruce and Stefan - Thanks for your replies. It sounds like I'm good
>>to go with the HDPE.
>>Regards, Bob
> 
> 
> 
> Short term - certainly.
> Long term - probably. Especially if you can live with it not looking so  
> nice and put it in a try or something to catch the mysterious deposits on  
> the outside.
> I didn't notice any significant structural problems, like it going brittle  
> or anything.
> 
> ST
> 

I've stored conc. HCl in HDPE bottles (what else is there ?), and 
noticed thin film of white salt near the lid opening after some months. 
I normally just rinse it off, and ignore it, but I'm intruded as what it 
can be. I know these bottles do not seal perfectly on the lid, so 
microscopic amounts of escaping HCl is inevitable. Wetted salts have a 
nasty habit of creeping through gaps and opening them up wider.

If your getting salt on the container body then use better bottles. I've 
never seen this happen, except my 70% nitric acid. Its in one of those 
black 'poison' labeled HDPE bottles and its continuously wet on the outside.

Adam

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Tue, 23 Aug 2005 12:08:57 +0200, bdl7431 <bdl7431@s...> wrote:
> 
> > However, the salt formation has me a bit puzzled - where did this
form -  
> > all
> > over the container or around the lid?
> > Bruce
> > PS:  I am a chemist in my real life.
> 
> 
> It has me puzzled too.
> Not around the lid, all over the bottle, under and maybe also above
liquid  
> level inside.
> Also, the HCl bottle appeared to get small protruding dimples after  
> several years, which is why i hadn't refilled it last time but
instead got  
> a new one.
> 
> I have no idea what the salt is, i am only guessing it is salt. It's a  
> white powder and somewhow it feels like a very fine salt to the touch.
> My workaround (to prevent getting it on my fingers) was to cut off a  
> larger bottle and use it as a sleeve around the bottle. Also, i
found if i  
> keep the HCl bottle really close to spray cans this isn't good, as
they  
> will rust at the seam. Note that the lids on those bottles are very  
> reliable, i'm sure the acid traces came "through" the bottle.
> 
> Those are the standard-issue bottles at my chemicals store, so i use
them  
> for lots of stuff and don't see this problem with anything else,
only with  
> white spirit there was a problem too, it evaporated throught the
bottle in  
> an amount that would cause it to deform inwards, i use a glass
bottle for  
> that now. I am surprised petrol doesn't evaporate through jerry cans
then,  
> maybe those are PP and not PE, no sure. Haven't observed any
contraction  
> of the can with those.
> 
> I would look forward to any guesses you might have as to what this
salt  
> might be, i've tried to find out but nobody came up with an
explanation so  
> far.
> 
> ST

I guess this salt can be ammonium chloride (NH4Cl)
I stored two HCl PE bottles for about 2 years and noticed
a thicker salt deposit on one of these bottles
It puzzled me because these bottled were otherwise identical
But one of them was standing near an ammonia bottle... and salt
deposit was nearly twice as thick as the other bottle
It easy to show: just open an hydrocholic acid and ammonia bottle
near each other, when HCl and NH3 mix in the air it forms whitish
NH4Cl fumes
I guess HCl and NH3 gas can slowly diffuse through PE and form NH4Cl 
on surface.
Deposit was seen only on hydrochric acid bottle on all the area
This phenomemnon also shows with an HCl bottle alone as air contains
small quantities of ammonia gas but salt growing is much slower

On Mon, 29 Aug 2005 10:44:51 +0200, dgallavardin <dgallavardin@...>  
wrote:

>
> I guess this salt can be ammonium chloride (NH4Cl)
> I stored two HCl PE bottles for about 2 years and noticed
> a thicker salt deposit on one of these bottles
> It puzzled me because these bottled were otherwise identical
> But one of them was standing near an ammonia bottle... and salt
> deposit was nearly twice as thick as the other bottle
> It easy to show: just open an hydrocholic acid and ammonia bottle
> near each other, when HCl and NH3 mix in the air it forms whitish
> NH4Cl fumes
> I guess HCl and NH3 gas can slowly diffuse through PE and form NH4Cl
> on surface.
> Deposit was seen only on hydrochric acid bottle on all the area
> This phenomemnon also shows with an HCl bottle alone as air contains
> small quantities of ammonia gas but salt growing is much slower
>


could well be...
i have ammonia containing products nearby.

ST