Nice rig!
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)
Watch this:
It is *really* a much better method.
Reg
When we were kids we used to use exactly the copper clad scratch method shown at 2:30 in the video, except we didn't have Exacto knives or Dremels back then, so we were just using a hand file and a piece of blade from a former dented metal sawing blade, or a broken knife, or a broken drill. Almost any metal was good enough, because copper is very soft, and we were not shy to reach the file and reshape again the scratching pick when necessary.
We also used to use concentrated nitric acid HNO
3 as a PCB etcher, for circuits too complicated to build on a scratched PCB. I still recall the brown fumes and the specific smell of nitric acid. We were about 4th grade, I think, and we were handling a bottel so big that would probably put any adult in prison nowadays, when the chemicals are so tight controlled. It was a huge glass bottle with thick walls and a matte glass stopper, the kind used for chemistry, 5 liters I guess, and it was about half with acid. The other half was always filled with some brown fumes.
It was hard to pour the acid without spilling, and every drop landed on the pavement was fizzling and bubbling a lot, and if a drop happen to land on the skin, the blister would have took many days to heal. However, our greatest fear was the smoke. We were told the brown smoke from the nitric acid is poisonous and to avoid it (which is correct), but it was outside. With acid in an open tray, the brown smoke was moving with the air currents, many times heading straight to us. We were many kids around that fuming tray, without any adults around, and we were running away like little squiggling piglets when the smoke was heading toward us
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif)
, then we were flocking again around the acid tray, and so on, back and forth for about a minute or so, until the etching was complete.
Being around the tray was a very high stake game, because the acid was etching very fast, with fizzling bubbles like it was sparkling water. With as little as 10 or 20 seconds too much etching, we would have ended with completely ruined PCBs. It was not only about loosing all the work and drawing effort (the PCB traces were drawn by hand, with paint or with tar, printers or computers were not yet a thing). It was mostly about wasting the copper clad that was so scarce.
However, the biggest fear of all, for us, was to avoid any drops of acid falling on our cloths. Or else, when we got back home our moms would have slapped us and punished us badly for ruining our cloth.
![Rant :rant:](https://www.eevblog.com/forum/Smileys/default/rant.gif)
It's funny how back then no mom was thinking to sue the electronic club or the teacher "for gross negligence with the kids", and instead just slap and guilt trip us for not being careful enough with our cloth.
![Blah :blah:](https://www.eevblog.com/forum/Smileys/default/blah.gif)
Today I would probably be arrested if I'll be caught outside, puoring 2 kilos of fuming HNO
3 in a tray!
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
I bet HNO
3 is illegal now, as a bomb precursor or a drug precursor, or something.
Yet, with all that acid and all that behavior back then (outrageously irresponsible for today norms), nobody "dieded" or got permanently "damaged".
![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
Sorry for the short offtopic novel.
w2aew has a few videos about circuit prototyping methods: