Etching solution is probably more well known as solution containing Iron(III) Chloride. This Iron (III) Chloride is probably very bad for our environment (it is) or toxic plus very acidic. (See Wikipedia here for more info.)
If you have kids in your house and you like to etch your own PCBs, having too much of this toxic, etching solution is probably not a smart idea nor is it great for the environment everytime you wash it down the toilet (or sink).
Now, there’s a better, environmentally-friendly way about doing your PCB Etching, that is by making your own DIY etching solutions, and I am not talking about this one where it uses hydrochloric acid, which is still bad.
Stephen Hobley, a gadgeteer/circuiteer of all sorts, has just found out that you can substitute all the toxic acid for white vinegar. His DIY etching solution basically consists of slightly diluted vinegar, hydrogen peroxide, and salt.
The important thing is that you get the copper to precipitate out, as the dark “rust” – if the liquid is just turning blue then this is not the reaction involving the salt – just the other two ingredients. This works too, but takes a long time.
Vinegar – Distilled White Vinegar – diluted with water to 5% acidity (Meijer)
Peroxide – 3% solution (Meijer)
Salt – to taste. (Just keep adding it until the “fizzing” continues all by itself).
Right now, I still don’t know what’s going on exactly – the fumes are slightly noxious – but only in a “OMG I just inhaled vinegar” kind of way. Repeat the experiment at your own risk.
Here’s a video of Stephen demonstrating his DIY etching solution in action:
That’s pretty ridiculously cool for environmentally-sensitive people like myself.
If you want to find out more about this DIY, check out Stephen’s blog post here.
And don’t forget to leave comments below on what you think of this DIY Etching Solution!