Homebrew PCBs

On Sun, 21 Aug 2005 22:10:56 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

>
> hydrogen peroxide (H2O2), is this the same as what I can purchase at
> the local drug store? Or, is there a stronger solution or something
> I have to get at a specialty supplier?

often the drug store stuff is only 3%, you want around 30% or you add too  
much water.

> hydrochloric acid (HCl), I know I have seen this for some purposes
> but can't recall common uses - toilet bowl cleaner perhaps?  Again,
> where would I purchase this, and is there a certain strength I
> should look for?

Around 30% is a common strength again, it has many uses, cleaning stuff  
like bricks, toilets, ...

I get both chemicals at my chemists shop. I don't remember the price  
exactly, but it is well below 10eur for a liter each, and that lasts you  
quite a while.


> With this chemical make up, do you still want to use a heater?

NO! HCl will form vapor somewhere low, around 50C, and even below it will  
create much more fumes when heated.

> Does anyone know which plastics will be okay to use as a tank for
> this type of etching? I was thinking of using Acrylics, but that
> stuff can be a pain in the ass to glue up good.  Then I thought
> about polystyrene which you can get translucent and I believe it can
> be glued up more readily.

Use glass. easier to cut and cheaper too.
Some plastics like lexan are said to be no good 'cause they take up water  
(etchant). I had it in a PET bottle the first year or so, ad it did go  
"through" that (salts on outside of bottle).
glued with RTV silicone holds up very well.


I've just boken the blade of my nibbler pliers stupidly. At the moment i'm  
still supressing thinking of it but i'll have to come to terms with it in  
a few minutes. Those are so darn expensive... I really didn't need that.

ST