Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [Homebrew_PCBs] CuCl etchant - an update

From: Sam Rod <mail4sam@...>
Date: 2013-09-07

Andy,
Im sure you have already established this But i say just to make sure your clear because the devil is n the details.

1: CuCl will eat/dissolve most plastics.
2: since most pre built parts like drip irrigation etc dont include their material of construction.
2a: the easiest way to determine is a stress test. By so called parts wire ties fittings etc. and submerge in the CuCl for at least
1-3 hours. then remove. if no signs of wear softness your prob good to go. 
3: Dont build your tank/assembly assuming the plastic is safe!.

To answer your question directly.  the answer is I dont know. But Ill take a guess and say NO its more likely that it will fail.
as cheaper plastics are used to make most of these parts.
your looking for plastic like Acrylic,Acetal,PVDC to name a few.
out of the hundred of plastics I would say less than a dozen are safe.

Be safe! and lucky too :)

Sam





On Sep 7, 2013, at 1:47 AM, Andrew Volk <amvweb@...> wrote:

 

Sam –

 

Thanks for the reply.  So you are saying that standard drip irrigation system components will be eaten by the CuCl etchant?

 

Andy

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Sam Rod
Sent: Friday, September 06, 2013 7:22 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] CuCl etchant - an update

 

 

Andy,

Their was no for me to know un less I did a stress test. 

I was hoping i would no have to build some elaborate heater so I chose

to submerge the heater un powered for an hour and then check the plastic fittings.

 

the fittings showed abso no wear or degradation. the final test was to test with heat. 

which I did several times. I will report though for me the heat did'nt seem to make 

any noticeable difference. That being said any further etches I have run with no heater installed 

less parts less chance of error.

 

Had it made some difference I might have even just bubbled the parts outdoors in the sun light.

Still not using the heater.

I mentioned earlier Im in Fl. their is no shortage of free heat here.

 

 

Last thing. In previous test I had many failures with alot of the plastic fittings. even wire ties.

they would dissolve 100%. I ended up redesigning so no wire ties are even needed 

and for the fittings I special ordered some PVDC based ones. All the other ones I tried failed.

including my drain elbow. 

 

Having a chem spill is the 2nd from the last thing one needs/wants.  In all of my research I find

it amazing not many people mention the incompatible plastic factor.

 

Ill add a close up video of the bubbler in action with some water and dye it truly works magnificent .

 

Sam




 

On Sep 6, 2013, at 9:24 PM, Andrew Volk <amvweb@...> wrote:



 

 

Sam –

 

Everything looks quite straightforward, except the heater.  It looks like it is completely immersed, cord and all, in the tank.  Am I seeing this right?  The heater is that water/etchant proof?

 

Andy

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of thesn1per
Sent: Friday, September 06, 2013 12:36 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: CuCl etchant - an update

 

 

All,
I posted up some pics of my tank broken down and assembled with and with out boards.
their are quite a few pics hard to take pics of clear plastic.

http://thesn1per.blogspot.com/2012/11/etching-tank-update-110812.html

Feel free to ask away but it should be pretty self evident.

Sam