Yep , me again I was going to get some Ferric Acid crystals today to make a circuit board (my first one ) but relised I had some funky stuff in the garage that might work. I have a 7 litre can of Phosphoric Acid Surface etching solution , its used for car spraying. Would this work for copper clad boards to make my PCB or is it a bit strong Rusty
Oh right, may be its got some thing else in as well then, cause this stuff eats away metal big time. I remeber years ago i put a rusty bike chain in the solution and forgot to take it out, next morning it had eaten the chain down to little bits at the bottom. Do you think it has some thing else in then. It must be able to eat away copper
Dropping coins in coke cleans them up lovely. I've also used coke to freshen up old stripboard. Makes it taste nasty, though.
But if Phosphoric acid is in coke then why cant the stong concentration in the etching solution I have work
It may work. All you risk to find out is one board. Do a test on some scrap. Phosphoric acid is a weak acid, its dissociation constant is low (one reason you can safely drink the stuff). I don't know off the top of my head whether the copper salts you'd get from the process would be ridiculously toxic or just mildly toxic, I'd have to crack some books to find out. (Not gonna happen.)
Ferric chloride isn't exactly harmless, so don't get it on your flesh. Ammonium persulphate is more pleasant to use, but is slower, and one problem with slow methods is the copper gets under-cut at the resist edges, so fine traces could end up sunk without trace. Stripboard is fine for anything working below radio frequencies.
