On 29/05/16 00:13, Harvey White madyn@... [Homebrew_PCBs] wrote:
ferric chloride every few months, the etching will last for years, which is way
cheaper than any ammonium persulfate setup. No heating above room temperature is
needed either. I started with an equal part of water with the ferric chloride
atleast 5 years ago and it still works well.
> On Sat, 28 May 2016 09:29:41 -0400, you wrote:If you use air agitation which adds oxygen and add half a cup of HCl to the
>
>> What about ammonium persulfate ? when I worked at the electronics plant that
>> was what we used to etch our boards. It is clear and turns blue as it etches
>> . we used to put it in a corningware baking pan and warm it with a hot plate
>> underneath . if you put more into the mix it of course eats away the copper
>> faster. In time it will take the shine off the corningware in the area where
>> the heat source was.
>
> Same kind of problem with price, I think. I could only buy it from a
> chemical supply plant, and it's rather expensive.
>
>> Have also used ferric chloride, it also works better if you warm it. Ferric
>> chloride is usually used in sewage treatment plants to coagulate the solids.
>
> Had used that for years, hard to find in good sized lots, 30
> bucks/gallon or more plus shipping.
>
> Peroxide and muriatic acid is far cheaper.
>
> If I could find a cheap source of ammonium persulphate, that would be
> nice.
>
> The stuff in the pool supply stores (Oxy-shock) is 10 bucks/kilo, and
> has trace ingredients (undisclosed). It does work, but I'm not happy
> at that price.
ferric chloride every few months, the etching will last for years, which is way
cheaper than any ammonium persulfate setup. No heating above room temperature is
needed either. I started with an equal part of water with the ferric chloride
atleast 5 years ago and it still works well.